diff --git a/lib/libc/sys/kqueue.2 b/lib/libc/sys/kqueue.2 index f80c89f75d78..68929e973dc0 100644 --- a/lib/libc/sys/kqueue.2 +++ b/lib/libc/sys/kqueue.2 @@ -1,855 +1,860 @@ .\" Copyright (c) 2000 Jonathan Lemon .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD$ .\" -.Dd September 30, 2021 +.Dd October 12, 2021 .Dt KQUEUE 2 .Os .Sh NAME .Nm kqueue , .Nm kevent .Nd kernel event notification mechanism .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In sys/event.h .Ft int .Fn kqueue "void" .Ft int .Fo kevent .Fa "int kq" .Fa "const struct kevent *changelist" .Fa "int nchanges" .Fa "struct kevent *eventlist" .Fa "int nevents" .Fa "const struct timespec *timeout" .Fc .Fn EV_SET "kev" ident filter flags fflags data udata .Sh DESCRIPTION The .Fn kqueue system call provides a generic method of notifying the user when an event happens or a condition holds, based on the results of small pieces of kernel code termed filters. A kevent is identified by the (ident, filter) pair; there may only be one unique kevent per kqueue. .Pp The filter is executed upon the initial registration of a kevent in order to detect whether a preexisting condition is present, and is also executed whenever an event is passed to the filter for evaluation. If the filter determines that the condition should be reported, then the kevent is placed on the kqueue for the user to retrieve. .Pp The filter is also run when the user attempts to retrieve the kevent from the kqueue. If the filter indicates that the condition that triggered the event no longer holds, the kevent is removed from the kqueue and is not returned. .Pp Multiple events which trigger the filter do not result in multiple kevents being placed on the kqueue; instead, the filter will aggregate the events into a single struct kevent. Calling .Fn close on a file descriptor will remove any kevents that reference the descriptor. .Pp The .Fn kqueue system call creates a new kernel event queue and returns a descriptor. The queue is not inherited by a child created with .Xr fork 2 . However, if .Xr rfork 2 is called without the .Dv RFFDG flag, then the descriptor table is shared, which will allow sharing of the kqueue between two processes. .Pp The .Fn kevent system call is used to register events with the queue, and return any pending events to the user. The .Fa changelist argument is a pointer to an array of .Va kevent structures, as defined in .In sys/event.h . All changes contained in the .Fa changelist are applied before any pending events are read from the queue. The .Fa nchanges argument gives the size of .Fa changelist . The .Fa eventlist argument is a pointer to an array of kevent structures. The .Fa nevents argument determines the size of .Fa eventlist . When .Fa nevents is zero, .Fn kevent will return immediately even if there is a .Fa timeout specified unlike .Xr select 2 . If .Fa timeout is a non-NULL pointer, it specifies a maximum interval to wait for an event, which will be interpreted as a struct timespec. If .Fa timeout is a NULL pointer, .Fn kevent waits indefinitely. To effect a poll, the .Fa timeout argument should be non-NULL, pointing to a zero-valued .Va timespec structure. The same array may be used for the .Fa changelist and .Fa eventlist . .Pp The .Fn EV_SET macro is provided for ease of initializing a kevent structure. .Pp The .Va kevent structure is defined as: .Bd -literal struct kevent { uintptr_t ident; /* identifier for this event */ short filter; /* filter for event */ u_short flags; /* action flags for kqueue */ u_int fflags; /* filter flag value */ int64_t data; /* filter data value */ void *udata; /* opaque user data identifier */ uint64_t ext[4]; /* extensions */ }; .Ed .Pp The fields of .Fa struct kevent are: .Bl -tag -width "Fa filter" .It Fa ident Value used to identify this event. The exact interpretation is determined by the attached filter, but often is a file descriptor. .It Fa filter Identifies the kernel filter used to process this event. The pre-defined system filters are described below. .It Fa flags Actions to perform on the event. .It Fa fflags Filter-specific flags. .It Fa data Filter-specific data value. .It Fa udata Opaque user-defined value passed through the kernel unchanged. .It Fa ext Extended data passed to and from kernel. The .Fa ext[0] and .Fa ext[1] members use is defined by the filter. If the filter does not use them, the members are copied unchanged. The .Fa ext[2] and .Fa ext[3] members are always passed through the kernel as-is, making additional context available to application. .El .Pp The .Va flags field can contain the following values: .Bl -tag -width EV_DISPATCH .It Dv EV_ADD Adds the event to the kqueue. Re-adding an existing event will modify the parameters of the original event, and not result in a duplicate entry. Adding an event automatically enables it, unless overridden by the EV_DISABLE flag. .It Dv EV_ENABLE Permit .Fn kevent to return the event if it is triggered. .It Dv EV_DISABLE Disable the event so .Fn kevent will not return it. The filter itself is not disabled. .It Dv EV_DISPATCH Disable the event source immediately after delivery of an event. See .Dv EV_DISABLE above. .It Dv EV_DELETE Removes the event from the kqueue. Events which are attached to file descriptors are automatically deleted on the last close of the descriptor. .It Dv EV_RECEIPT This flag is useful for making bulk changes to a kqueue without draining any pending events. When passed as input, it forces .Dv EV_ERROR to always be returned. When a filter is successfully added the .Va data field will be zero. Note that if this flag is encountered and there is no remaining space in .Fa eventlist to hold the .Dv EV_ERROR event, then subsequent changes will not get processed. .It Dv EV_ONESHOT Causes the event to return only the first occurrence of the filter being triggered. After the user retrieves the event from the kqueue, it is deleted. .It Dv EV_CLEAR After the event is retrieved by the user, its state is reset. This is useful for filters which report state transitions instead of the current state. Note that some filters may automatically set this flag internally. .It Dv EV_EOF Filters may set this flag to indicate filter-specific EOF condition. .It Dv EV_ERROR See .Sx RETURN VALUES below. .It Dv EV_KEEPUDATA Causes .Fn kevent to leave unchanged any .Fa udata associated with an existing event. This allows other aspects of the event to be modified without requiring the caller to know the .Fa udata value presently associated. This is especially useful with .Dv NOTE_TRIGGER or flags like .Dv EV_ENABLE . This flag may not be used with .Dv EV_ADD . .El .Pp The predefined system filters are listed below. Arguments may be passed to and from the filter via the .Va fflags and .Va data fields in the kevent structure. .Bl -tag -width "Dv EVFILT_PROCDESC" .It Dv EVFILT_READ Takes a descriptor as the identifier, and returns whenever there is data available to read. The behavior of the filter is slightly different depending on the descriptor type. .Bl -tag -width 2n .It Sockets Sockets which have previously been passed to .Fn listen return when there is an incoming connection pending. .Va data contains the size of the listen backlog. .Pp Other socket descriptors return when there is data to be read, subject to the .Dv SO_RCVLOWAT value of the socket buffer. This may be overridden with a per-filter low water mark at the time the filter is added by setting the .Dv NOTE_LOWAT flag in .Va fflags , and specifying the new low water mark in .Va data . On return, .Va data contains the number of bytes of protocol data available to read. .Pp If the read direction of the socket has shutdown, then the filter also sets .Dv EV_EOF in .Va flags , and returns the socket error (if any) in .Va fflags . It is possible for EOF to be returned (indicating the connection is gone) while there is still data pending in the socket buffer. .It Vnodes Returns when the file pointer is not at the end of file. .Va data contains the offset from current position to end of file, and may be negative. .Pp This behavior is different from .Xr poll 2 , where read events are triggered for regular files unconditionally. This event can be triggered unconditionally by setting the .Dv NOTE_FILE_POLL flag in .Va fflags . .It "Fifos, Pipes" Returns when the there is data to read; .Va data contains the number of bytes available. .Pp When the last writer disconnects, the filter will set .Dv EV_EOF in .Va flags . This will be cleared by the filter when a new writer connects, at which point the filter will resume waiting for data to become available before returning. .It "BPF devices" Returns when the BPF buffer is full, the BPF timeout has expired, or when the BPF has .Dq immediate mode enabled and there is any data to read; .Va data contains the number of bytes available. .It Eventfds Returns when the counter is greater than 0; .Va data contains the counter value, which must be cast to .Vt uint64_t . .It Kqueues Returns when pending events are present on the queue; .Va data contains the number of events available. .El .It Dv EVFILT_WRITE Takes a descriptor as the identifier, and returns whenever it is possible to write to the descriptor. For sockets, pipes and fifos, .Va data will contain the amount of space remaining in the write buffer. The filter will set .Dv EV_EOF when the reader disconnects, and for the fifo case, this will be cleared when a new reader connects. -Note that this filter is not supported for vnodes or BPF devices. +Note that this filter is not supported for vnodes. .Pp For sockets, the low water mark and socket error handling is identical to the .Dv EVFILT_READ case. .Pp For eventfds, .Va data will contain the maximum value that can be added to the counter without blocking. +.Pp +For BPF devices, the filter always indicates that it is possible to +write and +.Va data +will contain the MTU size of the underlying interface. .It Dv EVFILT_EMPTY Takes a descriptor as the identifier, and returns whenever there is no remaining data in the write buffer. .It Dv EVFILT_AIO Events for this filter are not registered with .Fn kevent directly but are registered via the .Va aio_sigevent member of an asynchronous I/O request when it is scheduled via an asynchronous I/O system call such as .Fn aio_read . The filter returns under the same conditions as .Fn aio_error . For more details on this filter see .Xr sigevent 3 and .Xr aio 4 . .It Dv EVFILT_VNODE Takes a file descriptor as the identifier and the events to watch for in .Va fflags , and returns when one or more of the requested events occurs on the descriptor. The events to monitor are: .Bl -tag -width "Dv NOTE_CLOSE_WRITE" .It Dv NOTE_ATTRIB The file referenced by the descriptor had its attributes changed. .It Dv NOTE_CLOSE A file descriptor referencing the monitored file, was closed. The closed file descriptor did not have write access. .It Dv NOTE_CLOSE_WRITE A file descriptor referencing the monitored file, was closed. The closed file descriptor had write access. .Pp This note, as well as .Dv NOTE_CLOSE , are not activated when files are closed forcibly by .Xr unmount 2 or .Xr revoke 2 . Instead, .Dv NOTE_REVOKE is sent for such events. .It Dv NOTE_DELETE The .Fn unlink system call was called on the file referenced by the descriptor. .It Dv NOTE_EXTEND For regular file, the file referenced by the descriptor was extended. .Pp For directory, reports that a directory entry was added or removed, as the result of rename operation. The .Dv NOTE_EXTEND event is not reported when a name is changed inside the directory. .It Dv NOTE_LINK The link count on the file changed. In particular, the .Dv NOTE_LINK event is reported if a subdirectory was created or deleted inside the directory referenced by the descriptor. .It Dv NOTE_OPEN The file referenced by the descriptor was opened. .It Dv NOTE_READ A read occurred on the file referenced by the descriptor. .It Dv NOTE_RENAME The file referenced by the descriptor was renamed. .It Dv NOTE_REVOKE Access to the file was revoked via .Xr revoke 2 or the underlying file system was unmounted. .It Dv NOTE_WRITE A write occurred on the file referenced by the descriptor. .El .Pp On return, .Va fflags contains the events which triggered the filter. .It Dv EVFILT_PROC Takes the process ID to monitor as the identifier and the events to watch for in .Va fflags , and returns when the process performs one or more of the requested events. If a process can normally see another process, it can attach an event to it. The events to monitor are: .Bl -tag -width "Dv NOTE_TRACKERR" .It Dv NOTE_EXIT The process has exited. The exit status will be stored in .Va data . .It Dv NOTE_FORK The process has called .Fn fork . .It Dv NOTE_EXEC The process has executed a new process via .Xr execve 2 or a similar call. .It Dv NOTE_TRACK Follow a process across .Fn fork calls. The parent process registers a new kevent to monitor the child process using the same .Va fflags as the original event. The child process will signal an event with .Dv NOTE_CHILD set in .Va fflags and the parent PID in .Va data . .Pp If the parent process fails to register a new kevent .Pq usually due to resource limitations , it will signal an event with .Dv NOTE_TRACKERR set in .Va fflags , and the child process will not signal a .Dv NOTE_CHILD event. .El .Pp On return, .Va fflags contains the events which triggered the filter. .It Dv EVFILT_PROCDESC Takes the process descriptor created by .Xr pdfork 2 to monitor as the identifier and the events to watch for in .Va fflags , and returns when the associated process performs one or more of the requested events. The events to monitor are: .Bl -tag -width "Dv NOTE_EXIT" .It Dv NOTE_EXIT The process has exited. The exit status will be stored in .Va data . .El .Pp On return, .Va fflags contains the events which triggered the filter. .It Dv EVFILT_SIGNAL Takes the signal number to monitor as the identifier and returns when the given signal is delivered to the process. This coexists with the .Fn signal and .Fn sigaction facilities, and has a lower precedence. The filter will record all attempts to deliver a signal to a process, even if the signal has been marked as .Dv SIG_IGN , except for the .Dv SIGCHLD signal, which, if ignored, will not be recorded by the filter. Event notification happens after normal signal delivery processing. .Va data returns the number of times the signal has occurred since the last call to .Fn kevent . This filter automatically sets the .Dv EV_CLEAR flag internally. .It Dv EVFILT_TIMER Establishes an arbitrary timer identified by .Va ident . When adding a timer, .Va data specifies the moment to fire the timer (for .Dv NOTE_ABSTIME ) or the timeout period. The timer will be periodic unless .Dv EV_ONESHOT or .Dv NOTE_ABSTIME is specified. On return, .Va data contains the number of times the timeout has expired since the last call to .Fn kevent . For non-monotonic timers, this filter automatically sets the .Dv EV_CLEAR flag internally. .Pp The filter accepts the following flags in the .Va fflags argument: .Bl -tag -width "Dv NOTE_MSECONDS" .It Dv NOTE_SECONDS .Va data is in seconds. .It Dv NOTE_MSECONDS .Va data is in milliseconds. .It Dv NOTE_USECONDS .Va data is in microseconds. .It Dv NOTE_NSECONDS .Va data is in nanoseconds. .It Dv NOTE_ABSTIME The specified expiration time is absolute. .El .Pp If .Va fflags is not set, the default is milliseconds. On return, .Va fflags contains the events which triggered the filter. .Pp Periodic timers with a specified timeout of 0 will be silently adjusted to timeout after 1 of the time units specified by the requested precision in .Va fflags . If an absolute time is specified that has already passed, then it is treated as if the current time were specified and the event will fire as soon as possible. .Pp If an existing timer is re-added, the existing timer will be effectively canceled (throwing away any undelivered record of previous timer expiration) and re-started using the new parameters contained in .Va data and .Va fflags . .Pp There is a system wide limit on the number of timers which is controlled by the .Va kern.kq_calloutmax sysctl. .It Dv EVFILT_USER Establishes a user event identified by .Va ident which is not associated with any kernel mechanism but is triggered by user level code. The lower 24 bits of the .Va fflags may be used for user defined flags and manipulated using the following: .Bl -tag -width "Dv NOTE_FFLAGSMASK" .It Dv NOTE_FFNOP Ignore the input .Va fflags . .It Dv NOTE_FFAND Bitwise AND .Va fflags . .It Dv NOTE_FFOR Bitwise OR .Va fflags . .It Dv NOTE_FFCOPY Copy .Va fflags . .It Dv NOTE_FFCTRLMASK Control mask for .Va fflags . .It Dv NOTE_FFLAGSMASK User defined flag mask for .Va fflags . .El .Pp A user event is triggered for output with the following: .Bl -tag -width "Dv NOTE_FFLAGSMASK" .It Dv NOTE_TRIGGER Cause the event to be triggered. .El .Pp On return, .Va fflags contains the users defined flags in the lower 24 bits. .El .Sh CANCELLATION BEHAVIOUR If .Fa nevents is non-zero, i.e., the function is potentially blocking, the call is a cancellation point. Otherwise, i.e., if .Fa nevents is zero, the call is not cancellable. Cancellation can only occur before any changes are made to the kqueue, or when the call was blocked and no changes to the queue were requested. .Sh RETURN VALUES The .Fn kqueue system call creates a new kernel event queue and returns a file descriptor. If there was an error creating the kernel event queue, a value of -1 is returned and errno set. .Pp The .Fn kevent system call returns the number of events placed in the .Fa eventlist , up to the value given by .Fa nevents . If an error occurs while processing an element of the .Fa changelist and there is enough room in the .Fa eventlist , then the event will be placed in the .Fa eventlist with .Dv EV_ERROR set in .Va flags and the system error in .Va data . Otherwise, .Dv -1 will be returned, and .Dv errno will be set to indicate the error condition. If the time limit expires, then .Fn kevent returns 0. .Sh EXAMPLES .Bd -literal -compact #include #include #include #include #include #include int main(int argc, char **argv) { struct kevent event; /* Event we want to monitor */ struct kevent tevent; /* Event triggered */ int kq, fd, ret; if (argc != 2) err(EXIT_FAILURE, "Usage: %s path\en", argv[0]); fd = open(argv[1], O_RDONLY); if (fd == -1) err(EXIT_FAILURE, "Failed to open '%s'", argv[1]); /* Create kqueue. */ kq = kqueue(); if (kq == -1) err(EXIT_FAILURE, "kqueue() failed"); /* Initialize kevent structure. */ EV_SET(&event, fd, EVFILT_VNODE, EV_ADD | EV_CLEAR, NOTE_WRITE, 0, NULL); /* Attach event to the kqueue. */ ret = kevent(kq, &event, 1, NULL, 0, NULL); if (ret == -1) err(EXIT_FAILURE, "kevent register"); if (event.flags & EV_ERROR) errx(EXIT_FAILURE, "Event error: %s", strerror(event.data)); for (;;) { /* Sleep until something happens. */ ret = kevent(kq, NULL, 0, &tevent, 1, NULL); if (ret == -1) { err(EXIT_FAILURE, "kevent wait"); } else if (ret > 0) { printf("Something was written in '%s'\en", argv[1]); } } } .Ed .Sh ERRORS The .Fn kqueue system call fails if: .Bl -tag -width Er .It Bq Er ENOMEM The kernel failed to allocate enough memory for the kernel queue. .It Bq Er ENOMEM The .Dv RLIMIT_KQUEUES rlimit (see .Xr getrlimit 2 ) for the current user would be exceeded. .It Bq Er EMFILE The per-process descriptor table is full. .It Bq Er ENFILE The system file table is full. .El .Pp The .Fn kevent system call fails if: .Bl -tag -width Er .It Bq Er EACCES The process does not have permission to register a filter. .It Bq Er EFAULT There was an error reading or writing the .Va kevent structure. .It Bq Er EBADF The specified descriptor is invalid. .It Bq Er EINTR A signal was delivered before the timeout expired and before any events were placed on the kqueue for return. .It Bq Er EINTR A cancellation request was delivered to the thread, but not yet handled. .It Bq Er EINVAL The specified time limit or filter is invalid. .It Bq Er EINVAL The specified length of the event or change lists is negative. .It Bq Er ENOENT The event could not be found to be modified or deleted. .It Bq Er ENOMEM No memory was available to register the event or, in the special case of a timer, the maximum number of timers has been exceeded. This maximum is configurable via the .Va kern.kq_calloutmax sysctl. .It Bq Er ESRCH The specified process to attach to does not exist. .El .Pp When .Fn kevent call fails with .Er EINTR error, all changes in the .Fa changelist have been applied. .Sh SEE ALSO .Xr aio_error 2 , .Xr aio_read 2 , .Xr aio_return 2 , .Xr poll 2 , .Xr read 2 , .Xr select 2 , .Xr sigaction 2 , .Xr write 2 , .Xr pthread_setcancelstate 3 , .Xr signal 3 .Rs .%A Jonathan Lemon .%T "Kqueue: A Generic and Scalable Event Notification Facility" .%I USENIX Association .%B Proceedings of the FREENIX Track: 2001 USENIX Annual Technical Conference .%D June 25-30, 2001 .\".http://www.usenix.org/event/usenix01/freenix01/full_papers/lemon/lemon.pdf .Re .Sh HISTORY The .Fn kqueue and .Fn kevent system calls first appeared in .Fx 4.1 . .Sh AUTHORS The .Fn kqueue system and this manual page were written by .An Jonathan Lemon Aq Mt jlemon@FreeBSD.org . .Sh BUGS The .Fa timeout value is limited to 24 hours; longer timeouts will be silently reinterpreted as 24 hours. .Pp In versions older than .Fx 12.0 , .In sys/event.h failed to parse without including .In sys/types.h manually. diff --git a/sys/net/bpf.c b/sys/net/bpf.c index 77c85cc91aae..ce7aba5a9bcd 100644 --- a/sys/net/bpf.c +++ b/sys/net/bpf.c @@ -1,3112 +1,3141 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1990, 1991, 1993 * The Regents of the University of California. All rights reserved. * Copyright (c) 2019 Andrey V. Elsukov * * This code is derived from the Stanford/CMU enet packet filter, * (net/enet.c) distributed as part of 4.3BSD, and code contributed * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence * Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)bpf.c 8.4 (Berkeley) 1/9/95 */ #include __FBSDID("$FreeBSD$"); #include "opt_bpf.h" #include "opt_ddb.h" #include "opt_netgraph.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #endif #include #include #include #include #include #include #ifdef BPF_JITTER #include #endif #include #include #include #include #include #include #include #include #include #include MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); static struct bpf_if_ext dead_bpf_if = { .bif_dlist = CK_LIST_HEAD_INITIALIZER() }; struct bpf_if { #define bif_next bif_ext.bif_next #define bif_dlist bif_ext.bif_dlist struct bpf_if_ext bif_ext; /* public members */ u_int bif_dlt; /* link layer type */ u_int bif_hdrlen; /* length of link header */ struct bpfd_list bif_wlist; /* writer-only list */ struct ifnet *bif_ifp; /* corresponding interface */ struct bpf_if **bif_bpf; /* Pointer to pointer to us */ volatile u_int bif_refcnt; struct epoch_context epoch_ctx; }; CTASSERT(offsetof(struct bpf_if, bif_ext) == 0); struct bpf_program_buffer { struct epoch_context epoch_ctx; #ifdef BPF_JITTER bpf_jit_filter *func; #endif void *buffer[0]; }; #if defined(DEV_BPF) || defined(NETGRAPH_BPF) #define PRINET 26 /* interruptible */ #define BPF_PRIO_MAX 7 #define SIZEOF_BPF_HDR(type) \ (offsetof(type, bh_hdrlen) + sizeof(((type *)0)->bh_hdrlen)) #ifdef COMPAT_FREEBSD32 #include #include #define BPF_ALIGNMENT32 sizeof(int32_t) #define BPF_WORDALIGN32(x) roundup2(x, BPF_ALIGNMENT32) #ifndef BURN_BRIDGES /* * 32-bit version of structure prepended to each packet. We use this header * instead of the standard one for 32-bit streams. We mark the a stream as * 32-bit the first time we see a 32-bit compat ioctl request. */ struct bpf_hdr32 { struct timeval32 bh_tstamp; /* time stamp */ uint32_t bh_caplen; /* length of captured portion */ uint32_t bh_datalen; /* original length of packet */ uint16_t bh_hdrlen; /* length of bpf header (this struct plus alignment padding) */ }; #endif struct bpf_program32 { u_int bf_len; uint32_t bf_insns; }; struct bpf_dltlist32 { u_int bfl_len; u_int bfl_list; }; #define BIOCSETF32 _IOW('B', 103, struct bpf_program32) #define BIOCSRTIMEOUT32 _IOW('B', 109, struct timeval32) #define BIOCGRTIMEOUT32 _IOR('B', 110, struct timeval32) #define BIOCGDLTLIST32 _IOWR('B', 121, struct bpf_dltlist32) #define BIOCSETWF32 _IOW('B', 123, struct bpf_program32) #define BIOCSETFNR32 _IOW('B', 130, struct bpf_program32) #endif #define BPF_LOCK() sx_xlock(&bpf_sx) #define BPF_UNLOCK() sx_xunlock(&bpf_sx) #define BPF_LOCK_ASSERT() sx_assert(&bpf_sx, SA_XLOCKED) /* * bpf_iflist is a list of BPF interface structures, each corresponding to a * specific DLT. The same network interface might have several BPF interface * structures registered by different layers in the stack (i.e., 802.11 * frames, ethernet frames, etc). */ CK_LIST_HEAD(bpf_iflist, bpf_if); static struct bpf_iflist bpf_iflist; static struct sx bpf_sx; /* bpf global lock */ static int bpf_bpfd_cnt; static void bpfif_ref(struct bpf_if *); static void bpfif_rele(struct bpf_if *); static void bpfd_ref(struct bpf_d *); static void bpfd_rele(struct bpf_d *); static void bpf_attachd(struct bpf_d *, struct bpf_if *); static void bpf_detachd(struct bpf_d *); static void bpf_detachd_locked(struct bpf_d *, bool); static void bpfd_free(epoch_context_t); static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, struct sockaddr *, int *, struct bpf_d *); static int bpf_setif(struct bpf_d *, struct ifreq *); static void bpf_timed_out(void *); static __inline void bpf_wakeup(struct bpf_d *); static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, void (*)(struct bpf_d *, caddr_t, u_int, void *, u_int), struct bintime *); static void reset_d(struct bpf_d *); static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); static int bpf_setdlt(struct bpf_d *, u_int); static void filt_bpfdetach(struct knote *); static int filt_bpfread(struct knote *, long); +static int filt_bpfwrite(struct knote *, long); static void bpf_drvinit(void *); static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "bpf sysctl"); int bpf_maxinsns = BPF_MAXINSNS; SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, &bpf_maxinsns, 0, "Maximum bpf program instructions"); static int bpf_zerocopy_enable = 0; SYSCTL_INT(_net_bpf, OID_AUTO, zerocopy_enable, CTLFLAG_RW, &bpf_zerocopy_enable, 0, "Enable new zero-copy BPF buffer sessions"); static SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_MPSAFE | CTLFLAG_RW, bpf_stats_sysctl, "bpf statistics portal"); VNET_DEFINE_STATIC(int, bpf_optimize_writers) = 0; #define V_bpf_optimize_writers VNET(bpf_optimize_writers) SYSCTL_INT(_net_bpf, OID_AUTO, optimize_writers, CTLFLAG_VNET | CTLFLAG_RWTUN, &VNET_NAME(bpf_optimize_writers), 0, "Do not send packets until BPF program is set"); static d_open_t bpfopen; static d_read_t bpfread; static d_write_t bpfwrite; static d_ioctl_t bpfioctl; static d_poll_t bpfpoll; static d_kqfilter_t bpfkqfilter; static struct cdevsw bpf_cdevsw = { .d_version = D_VERSION, .d_open = bpfopen, .d_read = bpfread, .d_write = bpfwrite, .d_ioctl = bpfioctl, .d_poll = bpfpoll, .d_name = "bpf", .d_kqfilter = bpfkqfilter, }; static struct filterops bpfread_filtops = { .f_isfd = 1, .f_detach = filt_bpfdetach, .f_event = filt_bpfread, }; +static struct filterops bpfwrite_filtops = { + .f_isfd = 1, + .f_detach = filt_bpfdetach, + .f_event = filt_bpfwrite, +}; + /* * LOCKING MODEL USED BY BPF * * Locks: * 1) global lock (BPF_LOCK). Sx, used to protect some global counters, * every bpf_iflist changes, serializes ioctl access to bpf descriptors. * 2) Descriptor lock. Mutex, used to protect BPF buffers and various * structure fields used by bpf_*tap* code. * * Lock order: global lock, then descriptor lock. * * There are several possible consumers: * * 1. The kernel registers interface pointer with bpfattach(). * Each call allocates new bpf_if structure, references ifnet pointer * and links bpf_if into bpf_iflist chain. This is protected with global * lock. * * 2. An userland application uses ioctl() call to bpf_d descriptor. * All such call are serialized with global lock. BPF filters can be * changed, but pointer to old filter will be freed using NET_EPOCH_CALL(). * Thus it should be safe for bpf_tap/bpf_mtap* code to do access to * filter pointers, even if change will happen during bpf_tap execution. * Destroying of bpf_d descriptor also is doing using NET_EPOCH_CALL(). * * 3. An userland application can write packets into bpf_d descriptor. * There we need to be sure, that ifnet won't disappear during bpfwrite(). * * 4. The kernel invokes bpf_tap/bpf_mtap* functions. The access to * bif_dlist is protected with net_epoch_preempt section. So, it should * be safe to make access to bpf_d descriptor inside the section. * * 5. The kernel invokes bpfdetach() on interface destroying. All lists * are modified with global lock held and actual free() is done using * NET_EPOCH_CALL(). */ static void bpfif_free(epoch_context_t ctx) { struct bpf_if *bp; bp = __containerof(ctx, struct bpf_if, epoch_ctx); if_rele(bp->bif_ifp); free(bp, M_BPF); } static void bpfif_ref(struct bpf_if *bp) { refcount_acquire(&bp->bif_refcnt); } static void bpfif_rele(struct bpf_if *bp) { if (!refcount_release(&bp->bif_refcnt)) return; NET_EPOCH_CALL(bpfif_free, &bp->epoch_ctx); } static void bpfd_ref(struct bpf_d *d) { refcount_acquire(&d->bd_refcnt); } static void bpfd_rele(struct bpf_d *d) { if (!refcount_release(&d->bd_refcnt)) return; NET_EPOCH_CALL(bpfd_free, &d->epoch_ctx); } static struct bpf_program_buffer* bpf_program_buffer_alloc(size_t size, int flags) { return (malloc(sizeof(struct bpf_program_buffer) + size, M_BPF, flags)); } static void bpf_program_buffer_free(epoch_context_t ctx) { struct bpf_program_buffer *ptr; ptr = __containerof(ctx, struct bpf_program_buffer, epoch_ctx); #ifdef BPF_JITTER if (ptr->func != NULL) bpf_destroy_jit_filter(ptr->func); #endif free(ptr, M_BPF); } /* * Wrapper functions for various buffering methods. If the set of buffer * modes expands, we will probably want to introduce a switch data structure * similar to protosw, et. */ static void bpf_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, void *src, u_int len) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return (bpf_buffer_append_bytes(d, buf, offset, src, len)); case BPF_BUFMODE_ZBUF: counter_u64_add(d->bd_zcopy, 1); return (bpf_zerocopy_append_bytes(d, buf, offset, src, len)); default: panic("bpf_buf_append_bytes"); } } static void bpf_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, u_int len) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return (bpf_buffer_append_mbuf(d, buf, offset, src, len)); case BPF_BUFMODE_ZBUF: counter_u64_add(d->bd_zcopy, 1); return (bpf_zerocopy_append_mbuf(d, buf, offset, src, len)); default: panic("bpf_buf_append_mbuf"); } } /* * This function gets called when the free buffer is re-assigned. */ static void bpf_buf_reclaimed(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return; case BPF_BUFMODE_ZBUF: bpf_zerocopy_buf_reclaimed(d); return; default: panic("bpf_buf_reclaimed"); } } /* * If the buffer mechanism has a way to decide that a held buffer can be made * free, then it is exposed via the bpf_canfreebuf() interface. (1) is * returned if the buffer can be discarded, (0) is returned if it cannot. */ static int bpf_canfreebuf(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: return (bpf_zerocopy_canfreebuf(d)); } return (0); } /* * Allow the buffer model to indicate that the current store buffer is * immutable, regardless of the appearance of space. Return (1) if the * buffer is writable, and (0) if not. */ static int bpf_canwritebuf(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: return (bpf_zerocopy_canwritebuf(d)); } return (1); } /* * Notify buffer model that an attempt to write to the store buffer has * resulted in a dropped packet, in which case the buffer may be considered * full. */ static void bpf_buffull(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: bpf_zerocopy_buffull(d); break; } } /* * Notify the buffer model that a buffer has moved into the hold position. */ void bpf_bufheld(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); switch (d->bd_bufmode) { case BPF_BUFMODE_ZBUF: bpf_zerocopy_bufheld(d); break; } } static void bpf_free(struct bpf_d *d) { switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: return (bpf_buffer_free(d)); case BPF_BUFMODE_ZBUF: return (bpf_zerocopy_free(d)); default: panic("bpf_buf_free"); } } static int bpf_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) { if (d->bd_bufmode != BPF_BUFMODE_BUFFER) return (EOPNOTSUPP); return (bpf_buffer_uiomove(d, buf, len, uio)); } static int bpf_ioctl_sblen(struct bpf_d *d, u_int *i) { if (d->bd_bufmode != BPF_BUFMODE_BUFFER) return (EOPNOTSUPP); return (bpf_buffer_ioctl_sblen(d, i)); } static int bpf_ioctl_getzmax(struct thread *td, struct bpf_d *d, size_t *i) { if (d->bd_bufmode != BPF_BUFMODE_ZBUF) return (EOPNOTSUPP); return (bpf_zerocopy_ioctl_getzmax(td, d, i)); } static int bpf_ioctl_rotzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) { if (d->bd_bufmode != BPF_BUFMODE_ZBUF) return (EOPNOTSUPP); return (bpf_zerocopy_ioctl_rotzbuf(td, d, bz)); } static int bpf_ioctl_setzbuf(struct thread *td, struct bpf_d *d, struct bpf_zbuf *bz) { if (d->bd_bufmode != BPF_BUFMODE_ZBUF) return (EOPNOTSUPP); return (bpf_zerocopy_ioctl_setzbuf(td, d, bz)); } /* * General BPF functions. */ static int bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, struct sockaddr *sockp, int *hdrlen, struct bpf_d *d) { const struct ieee80211_bpf_params *p; struct ether_header *eh; struct mbuf *m; int error; int len; int hlen; int slen; /* * Build a sockaddr based on the data link layer type. * We do this at this level because the ethernet header * is copied directly into the data field of the sockaddr. * In the case of SLIP, there is no header and the packet * is forwarded as is. * Also, we are careful to leave room at the front of the mbuf * for the link level header. */ switch (linktype) { case DLT_SLIP: sockp->sa_family = AF_INET; hlen = 0; break; case DLT_EN10MB: sockp->sa_family = AF_UNSPEC; /* XXX Would MAXLINKHDR be better? */ hlen = ETHER_HDR_LEN; break; case DLT_FDDI: sockp->sa_family = AF_IMPLINK; hlen = 0; break; case DLT_RAW: sockp->sa_family = AF_UNSPEC; hlen = 0; break; case DLT_NULL: /* * null interface types require a 4 byte pseudo header which * corresponds to the address family of the packet. */ sockp->sa_family = AF_UNSPEC; hlen = 4; break; case DLT_ATM_RFC1483: /* * en atm driver requires 4-byte atm pseudo header. * though it isn't standard, vpi:vci needs to be * specified anyway. */ sockp->sa_family = AF_UNSPEC; hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ break; case DLT_PPP: sockp->sa_family = AF_UNSPEC; hlen = 4; /* This should match PPP_HDRLEN */ break; case DLT_IEEE802_11: /* IEEE 802.11 wireless */ sockp->sa_family = AF_IEEE80211; hlen = 0; break; case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ sockp->sa_family = AF_IEEE80211; sockp->sa_len = 12; /* XXX != 0 */ hlen = sizeof(struct ieee80211_bpf_params); break; default: return (EIO); } len = uio->uio_resid; if (len < hlen || len - hlen > ifp->if_mtu) return (EMSGSIZE); /* Allocate a mbuf for our write, since m_get2 fails if len >= to MJUMPAGESIZE, use m_getjcl for bigger buffers */ m = m_get3(len, M_WAITOK, MT_DATA, M_PKTHDR); if (m == NULL) return (EIO); m->m_pkthdr.len = m->m_len = len; *mp = m; error = uiomove(mtod(m, u_char *), len, uio); if (error) goto bad; slen = bpf_filter(d->bd_wfilter, mtod(m, u_char *), len, len); if (slen == 0) { error = EPERM; goto bad; } /* Check for multicast destination */ switch (linktype) { case DLT_EN10MB: eh = mtod(m, struct ether_header *); if (ETHER_IS_MULTICAST(eh->ether_dhost)) { if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, ETHER_ADDR_LEN) == 0) m->m_flags |= M_BCAST; else m->m_flags |= M_MCAST; } if (d->bd_hdrcmplt == 0) { memcpy(eh->ether_shost, IF_LLADDR(ifp), sizeof(eh->ether_shost)); } break; } /* * Make room for link header, and copy it to sockaddr */ if (hlen != 0) { if (sockp->sa_family == AF_IEEE80211) { /* * Collect true length from the parameter header * NB: sockp is known to be zero'd so if we do a * short copy unspecified parameters will be * zero. * NB: packet may not be aligned after stripping * bpf params * XXX check ibp_vers */ p = mtod(m, const struct ieee80211_bpf_params *); hlen = p->ibp_len; if (hlen > sizeof(sockp->sa_data)) { error = EINVAL; goto bad; } } bcopy(mtod(m, const void *), sockp->sa_data, hlen); } *hdrlen = hlen; return (0); bad: m_freem(m); return (error); } /* * Attach descriptor to the bpf interface, i.e. make d listen on bp, * then reset its buffers and counters with reset_d(). */ static void bpf_attachd(struct bpf_d *d, struct bpf_if *bp) { int op_w; BPF_LOCK_ASSERT(); /* * Save sysctl value to protect from sysctl change * between reads */ op_w = V_bpf_optimize_writers || d->bd_writer; if (d->bd_bif != NULL) bpf_detachd_locked(d, false); /* * Point d at bp, and add d to the interface's list. * Since there are many applications using BPF for * sending raw packets only (dhcpd, cdpd are good examples) * we can delay adding d to the list of active listeners until * some filter is configured. */ BPFD_LOCK(d); /* * Hold reference to bpif while descriptor uses this interface. */ bpfif_ref(bp); d->bd_bif = bp; if (op_w != 0) { /* Add to writers-only list */ CK_LIST_INSERT_HEAD(&bp->bif_wlist, d, bd_next); /* * We decrement bd_writer on every filter set operation. * First BIOCSETF is done by pcap_open_live() to set up * snap length. After that appliation usually sets its own * filter. */ d->bd_writer = 2; } else CK_LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); reset_d(d); BPFD_UNLOCK(d); bpf_bpfd_cnt++; CTR3(KTR_NET, "%s: bpf_attach called by pid %d, adding to %s list", __func__, d->bd_pid, d->bd_writer ? "writer" : "active"); if (op_w == 0) EVENTHANDLER_INVOKE(bpf_track, bp->bif_ifp, bp->bif_dlt, 1); } /* * Check if we need to upgrade our descriptor @d from write-only mode. */ static int bpf_check_upgrade(u_long cmd, struct bpf_d *d, struct bpf_insn *fcode, int flen) { int is_snap, need_upgrade; /* * Check if we've already upgraded or new filter is empty. */ if (d->bd_writer == 0 || fcode == NULL) return (0); need_upgrade = 0; /* * Check if cmd looks like snaplen setting from * pcap_bpf.c:pcap_open_live(). * Note we're not checking .k value here: * while pcap_open_live() definitely sets to non-zero value, * we'd prefer to treat k=0 (deny ALL) case the same way: e.g. * do not consider upgrading immediately */ if (cmd == BIOCSETF && flen == 1 && fcode[0].code == (BPF_RET | BPF_K)) is_snap = 1; else is_snap = 0; if (is_snap == 0) { /* * We're setting first filter and it doesn't look like * setting snaplen. We're probably using bpf directly. * Upgrade immediately. */ need_upgrade = 1; } else { /* * Do not require upgrade by first BIOCSETF * (used to set snaplen) by pcap_open_live(). */ if (--d->bd_writer == 0) { /* * First snaplen filter has already * been set. This is probably catch-all * filter */ need_upgrade = 1; } } CTR5(KTR_NET, "%s: filter function set by pid %d, " "bd_writer counter %d, snap %d upgrade %d", __func__, d->bd_pid, d->bd_writer, is_snap, need_upgrade); return (need_upgrade); } /* * Detach a file from its interface. */ static void bpf_detachd(struct bpf_d *d) { BPF_LOCK(); bpf_detachd_locked(d, false); BPF_UNLOCK(); } static void bpf_detachd_locked(struct bpf_d *d, bool detached_ifp) { struct bpf_if *bp; struct ifnet *ifp; int error; BPF_LOCK_ASSERT(); CTR2(KTR_NET, "%s: detach required by pid %d", __func__, d->bd_pid); /* Check if descriptor is attached */ if ((bp = d->bd_bif) == NULL) return; BPFD_LOCK(d); /* Remove d from the interface's descriptor list. */ CK_LIST_REMOVE(d, bd_next); /* Save bd_writer value */ error = d->bd_writer; ifp = bp->bif_ifp; d->bd_bif = NULL; if (detached_ifp) { /* * Notify descriptor as it's detached, so that any * sleepers wake up and get ENXIO. */ bpf_wakeup(d); } BPFD_UNLOCK(d); bpf_bpfd_cnt--; /* Call event handler iff d is attached */ if (error == 0) EVENTHANDLER_INVOKE(bpf_track, ifp, bp->bif_dlt, 0); /* * Check if this descriptor had requested promiscuous mode. * If so and ifnet is not detached, turn it off. */ if (d->bd_promisc && !detached_ifp) { d->bd_promisc = 0; CURVNET_SET(ifp->if_vnet); error = ifpromisc(ifp, 0); CURVNET_RESTORE(); if (error != 0 && error != ENXIO) { /* * ENXIO can happen if a pccard is unplugged * Something is really wrong if we were able to put * the driver into promiscuous mode, but can't * take it out. */ if_printf(bp->bif_ifp, "bpf_detach: ifpromisc failed (%d)\n", error); } } bpfif_rele(bp); } /* * Close the descriptor by detaching it from its interface, * deallocating its buffers, and marking it free. */ static void bpf_dtor(void *data) { struct bpf_d *d = data; BPFD_LOCK(d); if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; BPFD_UNLOCK(d); funsetown(&d->bd_sigio); bpf_detachd(d); #ifdef MAC mac_bpfdesc_destroy(d); #endif /* MAC */ seldrain(&d->bd_sel); knlist_destroy(&d->bd_sel.si_note); callout_drain(&d->bd_callout); bpfd_rele(d); } /* * Open ethernet device. Returns ENXIO for illegal minor device number, * EBUSY if file is open by another process. */ /* ARGSUSED */ static int bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) { struct bpf_d *d; int error; d = malloc(sizeof(*d), M_BPF, M_WAITOK | M_ZERO); error = devfs_set_cdevpriv(d, bpf_dtor); if (error != 0) { free(d, M_BPF); return (error); } /* Setup counters */ d->bd_rcount = counter_u64_alloc(M_WAITOK); d->bd_dcount = counter_u64_alloc(M_WAITOK); d->bd_fcount = counter_u64_alloc(M_WAITOK); d->bd_wcount = counter_u64_alloc(M_WAITOK); d->bd_wfcount = counter_u64_alloc(M_WAITOK); d->bd_wdcount = counter_u64_alloc(M_WAITOK); d->bd_zcopy = counter_u64_alloc(M_WAITOK); /* * For historical reasons, perform a one-time initialization call to * the buffer routines, even though we're not yet committed to a * particular buffer method. */ bpf_buffer_init(d); if ((flags & FREAD) == 0) d->bd_writer = 2; d->bd_hbuf_in_use = 0; d->bd_bufmode = BPF_BUFMODE_BUFFER; d->bd_sig = SIGIO; d->bd_direction = BPF_D_INOUT; d->bd_refcnt = 1; BPF_PID_REFRESH(d, td); #ifdef MAC mac_bpfdesc_init(d); mac_bpfdesc_create(td->td_ucred, d); #endif mtx_init(&d->bd_lock, devtoname(dev), "bpf cdev lock", MTX_DEF); callout_init_mtx(&d->bd_callout, &d->bd_lock, 0); knlist_init_mtx(&d->bd_sel.si_note, &d->bd_lock); /* Disable VLAN pcp tagging. */ d->bd_pcp = 0; return (0); } /* * bpfread - read next chunk of packets from buffers */ static int bpfread(struct cdev *dev, struct uio *uio, int ioflag) { struct bpf_d *d; int error; int non_block; int timed_out; error = devfs_get_cdevpriv((void **)&d); if (error != 0) return (error); /* * Restrict application to use a buffer the same size as * as kernel buffers. */ if (uio->uio_resid != d->bd_bufsize) return (EINVAL); non_block = ((ioflag & O_NONBLOCK) != 0); BPFD_LOCK(d); BPF_PID_REFRESH_CUR(d); if (d->bd_bufmode != BPF_BUFMODE_BUFFER) { BPFD_UNLOCK(d); return (EOPNOTSUPP); } if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); timed_out = (d->bd_state == BPF_TIMED_OUT); d->bd_state = BPF_IDLE; while (d->bd_hbuf_in_use) { error = mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET|PCATCH, "bd_hbuf", 0); if (error != 0) { BPFD_UNLOCK(d); return (error); } } /* * If the hold buffer is empty, then do a timed sleep, which * ends when the timeout expires or when enough packets * have arrived to fill the store buffer. */ while (d->bd_hbuf == NULL) { if (d->bd_slen != 0) { /* * A packet(s) either arrived since the previous * read or arrived while we were asleep. */ if (d->bd_immediate || non_block || timed_out) { /* * Rotate the buffers and return what's here * if we are in immediate mode, non-blocking * flag is set, or this descriptor timed out. */ ROTATE_BUFFERS(d); break; } } /* * No data is available, check to see if the bpf device * is still pointed at a real interface. If not, return * ENXIO so that the userland process knows to rebind * it before using it again. */ if (d->bd_bif == NULL) { BPFD_UNLOCK(d); return (ENXIO); } if (non_block) { BPFD_UNLOCK(d); return (EWOULDBLOCK); } error = msleep(d, &d->bd_lock, PRINET|PCATCH, "bpf", d->bd_rtout); if (error == EINTR || error == ERESTART) { BPFD_UNLOCK(d); return (error); } if (error == EWOULDBLOCK) { /* * On a timeout, return what's in the buffer, * which may be nothing. If there is something * in the store buffer, we can rotate the buffers. */ if (d->bd_hbuf) /* * We filled up the buffer in between * getting the timeout and arriving * here, so we don't need to rotate. */ break; if (d->bd_slen == 0) { BPFD_UNLOCK(d); return (0); } ROTATE_BUFFERS(d); break; } } /* * At this point, we know we have something in the hold slot. */ d->bd_hbuf_in_use = 1; BPFD_UNLOCK(d); /* * Move data from hold buffer into user space. * We know the entire buffer is transferred since * we checked above that the read buffer is bpf_bufsize bytes. * * We do not have to worry about simultaneous reads because * we waited for sole access to the hold buffer above. */ error = bpf_uiomove(d, d->bd_hbuf, d->bd_hlen, uio); BPFD_LOCK(d); KASSERT(d->bd_hbuf != NULL, ("bpfread: lost bd_hbuf")); d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; bpf_buf_reclaimed(d); d->bd_hbuf_in_use = 0; wakeup(&d->bd_hbuf_in_use); BPFD_UNLOCK(d); return (error); } /* * If there are processes sleeping on this descriptor, wake them up. */ static __inline void bpf_wakeup(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); if (d->bd_state == BPF_WAITING) { callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; } wakeup(d); if (d->bd_async && d->bd_sig && d->bd_sigio) pgsigio(&d->bd_sigio, d->bd_sig, 0); selwakeuppri(&d->bd_sel, PRINET); KNOTE_LOCKED(&d->bd_sel.si_note, 0); } static void bpf_timed_out(void *arg) { struct bpf_d *d = (struct bpf_d *)arg; BPFD_LOCK_ASSERT(d); if (callout_pending(&d->bd_callout) || !callout_active(&d->bd_callout)) return; if (d->bd_state == BPF_WAITING) { d->bd_state = BPF_TIMED_OUT; if (d->bd_slen != 0) bpf_wakeup(d); } } static int bpf_ready(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); if (!bpf_canfreebuf(d) && d->bd_hlen != 0) return (1); if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && d->bd_slen != 0) return (1); return (0); } static int bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) { struct route ro; struct sockaddr dst; struct epoch_tracker et; struct bpf_if *bp; struct bpf_d *d; struct ifnet *ifp; struct mbuf *m, *mc; int error, hlen; error = devfs_get_cdevpriv((void **)&d); if (error != 0) return (error); NET_EPOCH_ENTER(et); BPFD_LOCK(d); BPF_PID_REFRESH_CUR(d); counter_u64_add(d->bd_wcount, 1); if ((bp = d->bd_bif) == NULL) { error = ENXIO; goto out_locked; } ifp = bp->bif_ifp; if ((ifp->if_flags & IFF_UP) == 0) { error = ENETDOWN; goto out_locked; } if (uio->uio_resid == 0) goto out_locked; bzero(&dst, sizeof(dst)); m = NULL; hlen = 0; /* * Take extra reference, unlock d and exit from epoch section, * since bpf_movein() can sleep. */ bpfd_ref(d); NET_EPOCH_EXIT(et); BPFD_UNLOCK(d); error = bpf_movein(uio, (int)bp->bif_dlt, ifp, &m, &dst, &hlen, d); if (error != 0) { counter_u64_add(d->bd_wdcount, 1); bpfd_rele(d); return (error); } BPFD_LOCK(d); /* * Check that descriptor is still attached to the interface. * This can happen on bpfdetach(). To avoid access to detached * ifnet, free mbuf and return ENXIO. */ if (d->bd_bif == NULL) { counter_u64_add(d->bd_wdcount, 1); BPFD_UNLOCK(d); bpfd_rele(d); m_freem(m); return (ENXIO); } counter_u64_add(d->bd_wfcount, 1); if (d->bd_hdrcmplt) dst.sa_family = pseudo_AF_HDRCMPLT; if (d->bd_feedback) { mc = m_dup(m, M_NOWAIT); if (mc != NULL) mc->m_pkthdr.rcvif = ifp; /* Set M_PROMISC for outgoing packets to be discarded. */ if (d->bd_direction == BPF_D_INOUT) m->m_flags |= M_PROMISC; } else mc = NULL; m->m_pkthdr.len -= hlen; m->m_len -= hlen; m->m_data += hlen; /* XXX */ CURVNET_SET(ifp->if_vnet); #ifdef MAC mac_bpfdesc_create_mbuf(d, m); if (mc != NULL) mac_bpfdesc_create_mbuf(d, mc); #endif bzero(&ro, sizeof(ro)); if (hlen != 0) { ro.ro_prepend = (u_char *)&dst.sa_data; ro.ro_plen = hlen; ro.ro_flags = RT_HAS_HEADER; } if (d->bd_pcp != 0) vlan_set_pcp(m, d->bd_pcp); /* Avoid possible recursion on BPFD_LOCK(). */ NET_EPOCH_ENTER(et); BPFD_UNLOCK(d); error = (*ifp->if_output)(ifp, m, &dst, &ro); if (error) counter_u64_add(d->bd_wdcount, 1); if (mc != NULL) { if (error == 0) (*ifp->if_input)(ifp, mc); else m_freem(mc); } NET_EPOCH_EXIT(et); CURVNET_RESTORE(); bpfd_rele(d); return (error); out_locked: counter_u64_add(d->bd_wdcount, 1); NET_EPOCH_EXIT(et); BPFD_UNLOCK(d); return (error); } /* * Reset a descriptor by flushing its packet buffer and clearing the receive * and drop counts. This is doable for kernel-only buffers, but with * zero-copy buffers, we can't write to (or rotate) buffers that are * currently owned by userspace. It would be nice if we could encapsulate * this logic in the buffer code rather than here. */ static void reset_d(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); while (d->bd_hbuf_in_use) mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, "bd_hbuf", 0); if ((d->bd_hbuf != NULL) && (d->bd_bufmode != BPF_BUFMODE_ZBUF || bpf_canfreebuf(d))) { /* Free the hold buffer. */ d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; bpf_buf_reclaimed(d); } if (bpf_canwritebuf(d)) d->bd_slen = 0; counter_u64_zero(d->bd_rcount); counter_u64_zero(d->bd_dcount); counter_u64_zero(d->bd_fcount); counter_u64_zero(d->bd_wcount); counter_u64_zero(d->bd_wfcount); counter_u64_zero(d->bd_wdcount); counter_u64_zero(d->bd_zcopy); } /* * FIONREAD Check for read packet available. * BIOCGBLEN Get buffer len [for read()]. * BIOCSETF Set read filter. * BIOCSETFNR Set read filter without resetting descriptor. * BIOCSETWF Set write filter. * BIOCFLUSH Flush read packet buffer. * BIOCPROMISC Put interface into promiscuous mode. * BIOCGDLT Get link layer type. * BIOCGETIF Get interface name. * BIOCSETIF Set interface. * BIOCSRTIMEOUT Set read timeout. * BIOCGRTIMEOUT Get read timeout. * BIOCGSTATS Get packet stats. * BIOCIMMEDIATE Set immediate mode. * BIOCVERSION Get filter language version. * BIOCGHDRCMPLT Get "header already complete" flag * BIOCSHDRCMPLT Set "header already complete" flag * BIOCGDIRECTION Get packet direction flag * BIOCSDIRECTION Set packet direction flag * BIOCGTSTAMP Get time stamp format and resolution. * BIOCSTSTAMP Set time stamp format and resolution. * BIOCLOCK Set "locked" flag * BIOCFEEDBACK Set packet feedback mode. * BIOCSETZBUF Set current zero-copy buffer locations. * BIOCGETZMAX Get maximum zero-copy buffer size. * BIOCROTZBUF Force rotation of zero-copy buffer * BIOCSETBUFMODE Set buffer mode. * BIOCGETBUFMODE Get current buffer mode. * BIOCSETVLANPCP Set VLAN PCP tag. */ /* ARGSUSED */ static int bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td) { struct bpf_d *d; int error; error = devfs_get_cdevpriv((void **)&d); if (error != 0) return (error); /* * Refresh PID associated with this descriptor. */ BPFD_LOCK(d); BPF_PID_REFRESH(d, td); if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; BPFD_UNLOCK(d); if (d->bd_locked == 1) { switch (cmd) { case BIOCGBLEN: case BIOCFLUSH: case BIOCGDLT: case BIOCGDLTLIST: #ifdef COMPAT_FREEBSD32 case BIOCGDLTLIST32: #endif case BIOCGETIF: case BIOCGRTIMEOUT: #if defined(COMPAT_FREEBSD32) && defined(__amd64__) case BIOCGRTIMEOUT32: #endif case BIOCGSTATS: case BIOCVERSION: case BIOCGRSIG: case BIOCGHDRCMPLT: case BIOCSTSTAMP: case BIOCFEEDBACK: case FIONREAD: case BIOCLOCK: case BIOCSRTIMEOUT: #if defined(COMPAT_FREEBSD32) && defined(__amd64__) case BIOCSRTIMEOUT32: #endif case BIOCIMMEDIATE: case TIOCGPGRP: case BIOCROTZBUF: break; default: return (EPERM); } } #ifdef COMPAT_FREEBSD32 /* * If we see a 32-bit compat ioctl, mark the stream as 32-bit so * that it will get 32-bit packet headers. */ switch (cmd) { case BIOCSETF32: case BIOCSETFNR32: case BIOCSETWF32: case BIOCGDLTLIST32: case BIOCGRTIMEOUT32: case BIOCSRTIMEOUT32: if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { BPFD_LOCK(d); d->bd_compat32 = 1; BPFD_UNLOCK(d); } } #endif CURVNET_SET(TD_TO_VNET(td)); switch (cmd) { default: error = EINVAL; break; /* * Check for read packet available. */ case FIONREAD: { int n; BPFD_LOCK(d); n = d->bd_slen; while (d->bd_hbuf_in_use) mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, PRINET, "bd_hbuf", 0); if (d->bd_hbuf) n += d->bd_hlen; BPFD_UNLOCK(d); *(int *)addr = n; break; } /* * Get buffer len [for read()]. */ case BIOCGBLEN: BPFD_LOCK(d); *(u_int *)addr = d->bd_bufsize; BPFD_UNLOCK(d); break; /* * Set buffer length. */ case BIOCSBLEN: error = bpf_ioctl_sblen(d, (u_int *)addr); break; /* * Set link layer read filter. */ case BIOCSETF: case BIOCSETFNR: case BIOCSETWF: #ifdef COMPAT_FREEBSD32 case BIOCSETF32: case BIOCSETFNR32: case BIOCSETWF32: #endif error = bpf_setf(d, (struct bpf_program *)addr, cmd); break; /* * Flush read packet buffer. */ case BIOCFLUSH: BPFD_LOCK(d); reset_d(d); BPFD_UNLOCK(d); break; /* * Put interface into promiscuous mode. */ case BIOCPROMISC: if (d->bd_bif == NULL) { /* * No interface attached yet. */ error = EINVAL; break; } if (d->bd_promisc == 0) { error = ifpromisc(d->bd_bif->bif_ifp, 1); if (error == 0) d->bd_promisc = 1; } break; /* * Get current data link type. */ case BIOCGDLT: BPF_LOCK(); if (d->bd_bif == NULL) error = EINVAL; else *(u_int *)addr = d->bd_bif->bif_dlt; BPF_UNLOCK(); break; /* * Get a list of supported data link types. */ #ifdef COMPAT_FREEBSD32 case BIOCGDLTLIST32: { struct bpf_dltlist32 *list32; struct bpf_dltlist dltlist; list32 = (struct bpf_dltlist32 *)addr; dltlist.bfl_len = list32->bfl_len; dltlist.bfl_list = PTRIN(list32->bfl_list); BPF_LOCK(); if (d->bd_bif == NULL) error = EINVAL; else { error = bpf_getdltlist(d, &dltlist); if (error == 0) list32->bfl_len = dltlist.bfl_len; } BPF_UNLOCK(); break; } #endif case BIOCGDLTLIST: BPF_LOCK(); if (d->bd_bif == NULL) error = EINVAL; else error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); BPF_UNLOCK(); break; /* * Set data link type. */ case BIOCSDLT: BPF_LOCK(); if (d->bd_bif == NULL) error = EINVAL; else error = bpf_setdlt(d, *(u_int *)addr); BPF_UNLOCK(); break; /* * Get interface name. */ case BIOCGETIF: BPF_LOCK(); if (d->bd_bif == NULL) error = EINVAL; else { struct ifnet *const ifp = d->bd_bif->bif_ifp; struct ifreq *const ifr = (struct ifreq *)addr; strlcpy(ifr->ifr_name, ifp->if_xname, sizeof(ifr->ifr_name)); } BPF_UNLOCK(); break; /* * Set interface. */ case BIOCSETIF: { int alloc_buf, size; /* * Behavior here depends on the buffering model. If * we're using kernel memory buffers, then we can * allocate them here. If we're using zero-copy, * then the user process must have registered buffers * by the time we get here. */ alloc_buf = 0; BPFD_LOCK(d); if (d->bd_bufmode == BPF_BUFMODE_BUFFER && d->bd_sbuf == NULL) alloc_buf = 1; BPFD_UNLOCK(d); if (alloc_buf) { size = d->bd_bufsize; error = bpf_buffer_ioctl_sblen(d, &size); if (error != 0) break; } BPF_LOCK(); error = bpf_setif(d, (struct ifreq *)addr); BPF_UNLOCK(); break; } /* * Set read timeout. */ case BIOCSRTIMEOUT: #if defined(COMPAT_FREEBSD32) && defined(__amd64__) case BIOCSRTIMEOUT32: #endif { struct timeval *tv = (struct timeval *)addr; #if defined(COMPAT_FREEBSD32) && !defined(__mips__) struct timeval32 *tv32; struct timeval tv64; if (cmd == BIOCSRTIMEOUT32) { tv32 = (struct timeval32 *)addr; tv = &tv64; tv->tv_sec = tv32->tv_sec; tv->tv_usec = tv32->tv_usec; } else #endif tv = (struct timeval *)addr; /* * Subtract 1 tick from tvtohz() since this isn't * a one-shot timer. */ if ((error = itimerfix(tv)) == 0) d->bd_rtout = tvtohz(tv) - 1; break; } /* * Get read timeout. */ case BIOCGRTIMEOUT: #if defined(COMPAT_FREEBSD32) && defined(__amd64__) case BIOCGRTIMEOUT32: #endif { struct timeval *tv; #if defined(COMPAT_FREEBSD32) && defined(__amd64__) struct timeval32 *tv32; struct timeval tv64; if (cmd == BIOCGRTIMEOUT32) tv = &tv64; else #endif tv = (struct timeval *)addr; tv->tv_sec = d->bd_rtout / hz; tv->tv_usec = (d->bd_rtout % hz) * tick; #if defined(COMPAT_FREEBSD32) && defined(__amd64__) if (cmd == BIOCGRTIMEOUT32) { tv32 = (struct timeval32 *)addr; tv32->tv_sec = tv->tv_sec; tv32->tv_usec = tv->tv_usec; } #endif break; } /* * Get packet stats. */ case BIOCGSTATS: { struct bpf_stat *bs = (struct bpf_stat *)addr; /* XXXCSJP overflow */ bs->bs_recv = (u_int)counter_u64_fetch(d->bd_rcount); bs->bs_drop = (u_int)counter_u64_fetch(d->bd_dcount); break; } /* * Set immediate mode. */ case BIOCIMMEDIATE: BPFD_LOCK(d); d->bd_immediate = *(u_int *)addr; BPFD_UNLOCK(d); break; case BIOCVERSION: { struct bpf_version *bv = (struct bpf_version *)addr; bv->bv_major = BPF_MAJOR_VERSION; bv->bv_minor = BPF_MINOR_VERSION; break; } /* * Get "header already complete" flag */ case BIOCGHDRCMPLT: BPFD_LOCK(d); *(u_int *)addr = d->bd_hdrcmplt; BPFD_UNLOCK(d); break; /* * Set "header already complete" flag */ case BIOCSHDRCMPLT: BPFD_LOCK(d); d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; BPFD_UNLOCK(d); break; /* * Get packet direction flag */ case BIOCGDIRECTION: BPFD_LOCK(d); *(u_int *)addr = d->bd_direction; BPFD_UNLOCK(d); break; /* * Set packet direction flag */ case BIOCSDIRECTION: { u_int direction; direction = *(u_int *)addr; switch (direction) { case BPF_D_IN: case BPF_D_INOUT: case BPF_D_OUT: BPFD_LOCK(d); d->bd_direction = direction; BPFD_UNLOCK(d); break; default: error = EINVAL; } } break; /* * Get packet timestamp format and resolution. */ case BIOCGTSTAMP: BPFD_LOCK(d); *(u_int *)addr = d->bd_tstamp; BPFD_UNLOCK(d); break; /* * Set packet timestamp format and resolution. */ case BIOCSTSTAMP: { u_int func; func = *(u_int *)addr; if (BPF_T_VALID(func)) d->bd_tstamp = func; else error = EINVAL; } break; case BIOCFEEDBACK: BPFD_LOCK(d); d->bd_feedback = *(u_int *)addr; BPFD_UNLOCK(d); break; case BIOCLOCK: BPFD_LOCK(d); d->bd_locked = 1; BPFD_UNLOCK(d); break; case FIONBIO: /* Non-blocking I/O */ break; case FIOASYNC: /* Send signal on receive packets */ BPFD_LOCK(d); d->bd_async = *(int *)addr; BPFD_UNLOCK(d); break; case FIOSETOWN: /* * XXX: Add some sort of locking here? * fsetown() can sleep. */ error = fsetown(*(int *)addr, &d->bd_sigio); break; case FIOGETOWN: BPFD_LOCK(d); *(int *)addr = fgetown(&d->bd_sigio); BPFD_UNLOCK(d); break; /* This is deprecated, FIOSETOWN should be used instead. */ case TIOCSPGRP: error = fsetown(-(*(int *)addr), &d->bd_sigio); break; /* This is deprecated, FIOGETOWN should be used instead. */ case TIOCGPGRP: *(int *)addr = -fgetown(&d->bd_sigio); break; case BIOCSRSIG: /* Set receive signal */ { u_int sig; sig = *(u_int *)addr; if (sig >= NSIG) error = EINVAL; else { BPFD_LOCK(d); d->bd_sig = sig; BPFD_UNLOCK(d); } break; } case BIOCGRSIG: BPFD_LOCK(d); *(u_int *)addr = d->bd_sig; BPFD_UNLOCK(d); break; case BIOCGETBUFMODE: BPFD_LOCK(d); *(u_int *)addr = d->bd_bufmode; BPFD_UNLOCK(d); break; case BIOCSETBUFMODE: /* * Allow the buffering mode to be changed as long as we * haven't yet committed to a particular mode. Our * definition of commitment, for now, is whether or not a * buffer has been allocated or an interface attached, since * that's the point where things get tricky. */ switch (*(u_int *)addr) { case BPF_BUFMODE_BUFFER: break; case BPF_BUFMODE_ZBUF: if (bpf_zerocopy_enable) break; /* FALLSTHROUGH */ default: CURVNET_RESTORE(); return (EINVAL); } BPFD_LOCK(d); if (d->bd_sbuf != NULL || d->bd_hbuf != NULL || d->bd_fbuf != NULL || d->bd_bif != NULL) { BPFD_UNLOCK(d); CURVNET_RESTORE(); return (EBUSY); } d->bd_bufmode = *(u_int *)addr; BPFD_UNLOCK(d); break; case BIOCGETZMAX: error = bpf_ioctl_getzmax(td, d, (size_t *)addr); break; case BIOCSETZBUF: error = bpf_ioctl_setzbuf(td, d, (struct bpf_zbuf *)addr); break; case BIOCROTZBUF: error = bpf_ioctl_rotzbuf(td, d, (struct bpf_zbuf *)addr); break; case BIOCSETVLANPCP: { u_int pcp; pcp = *(u_int *)addr; if (pcp > BPF_PRIO_MAX || pcp < 0) { error = EINVAL; break; } d->bd_pcp = pcp; break; } } CURVNET_RESTORE(); return (error); } /* * Set d's packet filter program to fp. If this file already has a filter, * free it and replace it. Returns EINVAL for bogus requests. * * Note we use global lock here to serialize bpf_setf() and bpf_setif() * calls. */ static int bpf_setf(struct bpf_d *d, struct bpf_program *fp, u_long cmd) { #ifdef COMPAT_FREEBSD32 struct bpf_program fp_swab; struct bpf_program32 *fp32; #endif struct bpf_program_buffer *fcode; struct bpf_insn *filter; #ifdef BPF_JITTER bpf_jit_filter *jfunc; #endif size_t size; u_int flen; bool track_event; #ifdef COMPAT_FREEBSD32 switch (cmd) { case BIOCSETF32: case BIOCSETWF32: case BIOCSETFNR32: fp32 = (struct bpf_program32 *)fp; fp_swab.bf_len = fp32->bf_len; fp_swab.bf_insns = (struct bpf_insn *)(uintptr_t)fp32->bf_insns; fp = &fp_swab; switch (cmd) { case BIOCSETF32: cmd = BIOCSETF; break; case BIOCSETWF32: cmd = BIOCSETWF; break; } break; } #endif filter = NULL; #ifdef BPF_JITTER jfunc = NULL; #endif /* * Check new filter validness before acquiring any locks. * Allocate memory for new filter, if needed. */ flen = fp->bf_len; if (flen > bpf_maxinsns || (fp->bf_insns == NULL && flen != 0)) return (EINVAL); size = flen * sizeof(*fp->bf_insns); if (size > 0) { /* We're setting up new filter. Copy and check actual data. */ fcode = bpf_program_buffer_alloc(size, M_WAITOK); filter = (struct bpf_insn *)fcode->buffer; if (copyin(fp->bf_insns, filter, size) != 0 || !bpf_validate(filter, flen)) { free(fcode, M_BPF); return (EINVAL); } #ifdef BPF_JITTER if (cmd != BIOCSETWF) { /* * Filter is copied inside fcode and is * perfectly valid. */ jfunc = bpf_jitter(filter, flen); } #endif } track_event = false; fcode = NULL; BPF_LOCK(); BPFD_LOCK(d); /* Set up new filter. */ if (cmd == BIOCSETWF) { if (d->bd_wfilter != NULL) { fcode = __containerof((void *)d->bd_wfilter, struct bpf_program_buffer, buffer); #ifdef BPF_JITTER fcode->func = NULL; #endif } d->bd_wfilter = filter; } else { if (d->bd_rfilter != NULL) { fcode = __containerof((void *)d->bd_rfilter, struct bpf_program_buffer, buffer); #ifdef BPF_JITTER fcode->func = d->bd_bfilter; #endif } d->bd_rfilter = filter; #ifdef BPF_JITTER d->bd_bfilter = jfunc; #endif if (cmd == BIOCSETF) reset_d(d); if (bpf_check_upgrade(cmd, d, filter, flen) != 0) { /* * Filter can be set several times without * specifying interface. In this case just mark d * as reader. */ d->bd_writer = 0; if (d->bd_bif != NULL) { /* * Remove descriptor from writers-only list * and add it to active readers list. */ CK_LIST_REMOVE(d, bd_next); CK_LIST_INSERT_HEAD(&d->bd_bif->bif_dlist, d, bd_next); CTR2(KTR_NET, "%s: upgrade required by pid %d", __func__, d->bd_pid); track_event = true; } } } BPFD_UNLOCK(d); if (fcode != NULL) NET_EPOCH_CALL(bpf_program_buffer_free, &fcode->epoch_ctx); if (track_event) EVENTHANDLER_INVOKE(bpf_track, d->bd_bif->bif_ifp, d->bd_bif->bif_dlt, 1); BPF_UNLOCK(); return (0); } /* * Detach a file from its current interface (if attached at all) and attach * to the interface indicated by the name stored in ifr. * Return an errno or 0. */ static int bpf_setif(struct bpf_d *d, struct ifreq *ifr) { struct bpf_if *bp; struct ifnet *theywant; BPF_LOCK_ASSERT(); theywant = ifunit(ifr->ifr_name); if (theywant == NULL || theywant->if_bpf == NULL) return (ENXIO); bp = theywant->if_bpf; /* * At this point, we expect the buffer is already allocated. If not, * return an error. */ switch (d->bd_bufmode) { case BPF_BUFMODE_BUFFER: case BPF_BUFMODE_ZBUF: if (d->bd_sbuf == NULL) return (EINVAL); break; default: panic("bpf_setif: bufmode %d", d->bd_bufmode); } if (bp != d->bd_bif) bpf_attachd(d, bp); else { BPFD_LOCK(d); reset_d(d); BPFD_UNLOCK(d); } return (0); } /* * Support for select() and poll() system calls * * Return true iff the specific operation will not block indefinitely. * Otherwise, return false but make a note that a selwakeup() must be done. */ static int bpfpoll(struct cdev *dev, int events, struct thread *td) { struct bpf_d *d; int revents; if (devfs_get_cdevpriv((void **)&d) != 0 || d->bd_bif == NULL) return (events & (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM)); /* * Refresh PID associated with this descriptor. */ revents = events & (POLLOUT | POLLWRNORM); BPFD_LOCK(d); BPF_PID_REFRESH(d, td); if (events & (POLLIN | POLLRDNORM)) { if (bpf_ready(d)) revents |= events & (POLLIN | POLLRDNORM); else { selrecord(td, &d->bd_sel); /* Start the read timeout if necessary. */ if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { callout_reset(&d->bd_callout, d->bd_rtout, bpf_timed_out, d); d->bd_state = BPF_WAITING; } } } BPFD_UNLOCK(d); return (revents); } /* * Support for kevent() system call. Register EVFILT_READ filters and * reject all others. */ int bpfkqfilter(struct cdev *dev, struct knote *kn) { struct bpf_d *d; - if (devfs_get_cdevpriv((void **)&d) != 0 || - kn->kn_filter != EVFILT_READ) + if (devfs_get_cdevpriv((void **)&d) != 0) return (1); + switch (kn->kn_filter) { + case EVFILT_READ: + kn->kn_fop = &bpfread_filtops; + break; + + case EVFILT_WRITE: + kn->kn_fop = &bpfwrite_filtops; + break; + + default: + return (1); + } + /* * Refresh PID associated with this descriptor. */ BPFD_LOCK(d); BPF_PID_REFRESH_CUR(d); - kn->kn_fop = &bpfread_filtops; kn->kn_hook = d; knlist_add(&d->bd_sel.si_note, kn, 1); BPFD_UNLOCK(d); return (0); } static void filt_bpfdetach(struct knote *kn) { struct bpf_d *d = (struct bpf_d *)kn->kn_hook; knlist_remove(&d->bd_sel.si_note, kn, 0); } static int filt_bpfread(struct knote *kn, long hint) { struct bpf_d *d = (struct bpf_d *)kn->kn_hook; int ready; BPFD_LOCK_ASSERT(d); ready = bpf_ready(d); if (ready) { kn->kn_data = d->bd_slen; /* * Ignore the hold buffer if it is being copied to user space. */ if (!d->bd_hbuf_in_use && d->bd_hbuf) kn->kn_data += d->bd_hlen; } else if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { callout_reset(&d->bd_callout, d->bd_rtout, bpf_timed_out, d); d->bd_state = BPF_WAITING; } return (ready); } +static int +filt_bpfwrite(struct knote *kn, long hint) +{ + struct bpf_d *d = (struct bpf_d *)kn->kn_hook; + BPFD_LOCK_ASSERT(d); + + kn->kn_data = d->bd_bif->bif_ifp->if_mtu; + + return (1); +} + #define BPF_TSTAMP_NONE 0 #define BPF_TSTAMP_FAST 1 #define BPF_TSTAMP_NORMAL 2 #define BPF_TSTAMP_EXTERN 3 static int bpf_ts_quality(int tstype) { if (tstype == BPF_T_NONE) return (BPF_TSTAMP_NONE); if ((tstype & BPF_T_FAST) != 0) return (BPF_TSTAMP_FAST); return (BPF_TSTAMP_NORMAL); } static int bpf_gettime(struct bintime *bt, int tstype, struct mbuf *m) { struct m_tag *tag; int quality; quality = bpf_ts_quality(tstype); if (quality == BPF_TSTAMP_NONE) return (quality); if (m != NULL) { tag = m_tag_locate(m, MTAG_BPF, MTAG_BPF_TIMESTAMP, NULL); if (tag != NULL) { *bt = *(struct bintime *)(tag + 1); return (BPF_TSTAMP_EXTERN); } } if (quality == BPF_TSTAMP_NORMAL) binuptime(bt); else getbinuptime(bt); return (quality); } /* * Incoming linkage from device drivers. Process the packet pkt, of length * pktlen, which is stored in a contiguous buffer. The packet is parsed * by each process' filter, and if accepted, stashed into the corresponding * buffer. */ void bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) { struct epoch_tracker et; struct bintime bt; struct bpf_d *d; #ifdef BPF_JITTER bpf_jit_filter *bf; #endif u_int slen; int gottime; gottime = BPF_TSTAMP_NONE; NET_EPOCH_ENTER(et); CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { counter_u64_add(d->bd_rcount, 1); /* * NB: We dont call BPF_CHECK_DIRECTION() here since there * is no way for the caller to indiciate to us whether this * packet is inbound or outbound. In the bpf_mtap() routines, * we use the interface pointers on the mbuf to figure it out. */ #ifdef BPF_JITTER bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; if (bf != NULL) slen = (*(bf->func))(pkt, pktlen, pktlen); else #endif slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); if (slen != 0) { /* * Filter matches. Let's to acquire write lock. */ BPFD_LOCK(d); counter_u64_add(d->bd_fcount, 1); if (gottime < bpf_ts_quality(d->bd_tstamp)) gottime = bpf_gettime(&bt, d->bd_tstamp, NULL); #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, pkt, pktlen, slen, bpf_append_bytes, &bt); BPFD_UNLOCK(d); } } NET_EPOCH_EXIT(et); } #define BPF_CHECK_DIRECTION(d, r, i) \ (((d)->bd_direction == BPF_D_IN && (r) != (i)) || \ ((d)->bd_direction == BPF_D_OUT && (r) == (i))) /* * Incoming linkage from device drivers, when packet is in an mbuf chain. * Locking model is explained in bpf_tap(). */ void bpf_mtap(struct bpf_if *bp, struct mbuf *m) { struct epoch_tracker et; struct bintime bt; struct bpf_d *d; #ifdef BPF_JITTER bpf_jit_filter *bf; #endif u_int pktlen, slen; int gottime; /* Skip outgoing duplicate packets. */ if ((m->m_flags & M_PROMISC) != 0 && m_rcvif(m) == NULL) { m->m_flags &= ~M_PROMISC; return; } pktlen = m_length(m, NULL); gottime = BPF_TSTAMP_NONE; NET_EPOCH_ENTER(et); CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { if (BPF_CHECK_DIRECTION(d, m_rcvif(m), bp->bif_ifp)) continue; counter_u64_add(d->bd_rcount, 1); #ifdef BPF_JITTER bf = bpf_jitter_enable != 0 ? d->bd_bfilter : NULL; /* XXX We cannot handle multiple mbufs. */ if (bf != NULL && m->m_next == NULL) slen = (*(bf->func))(mtod(m, u_char *), pktlen, pktlen); else #endif slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); if (slen != 0) { BPFD_LOCK(d); counter_u64_add(d->bd_fcount, 1); if (gottime < bpf_ts_quality(d->bd_tstamp)) gottime = bpf_gettime(&bt, d->bd_tstamp, m); #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, (u_char *)m, pktlen, slen, bpf_append_mbuf, &bt); BPFD_UNLOCK(d); } } NET_EPOCH_EXIT(et); } /* * Incoming linkage from device drivers, when packet is in * an mbuf chain and to be prepended by a contiguous header. */ void bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) { struct epoch_tracker et; struct bintime bt; struct mbuf mb; struct bpf_d *d; u_int pktlen, slen; int gottime; /* Skip outgoing duplicate packets. */ if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) { m->m_flags &= ~M_PROMISC; return; } pktlen = m_length(m, NULL); /* * Craft on-stack mbuf suitable for passing to bpf_filter. * Note that we cut corners here; we only setup what's * absolutely needed--this mbuf should never go anywhere else. */ mb.m_flags = 0; mb.m_next = m; mb.m_data = data; mb.m_len = dlen; pktlen += dlen; gottime = BPF_TSTAMP_NONE; NET_EPOCH_ENTER(et); CK_LIST_FOREACH(d, &bp->bif_dlist, bd_next) { if (BPF_CHECK_DIRECTION(d, m->m_pkthdr.rcvif, bp->bif_ifp)) continue; counter_u64_add(d->bd_rcount, 1); slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); if (slen != 0) { BPFD_LOCK(d); counter_u64_add(d->bd_fcount, 1); if (gottime < bpf_ts_quality(d->bd_tstamp)) gottime = bpf_gettime(&bt, d->bd_tstamp, m); #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, (u_char *)&mb, pktlen, slen, bpf_append_mbuf, &bt); BPFD_UNLOCK(d); } } NET_EPOCH_EXIT(et); } #undef BPF_CHECK_DIRECTION #undef BPF_TSTAMP_NONE #undef BPF_TSTAMP_FAST #undef BPF_TSTAMP_NORMAL #undef BPF_TSTAMP_EXTERN static int bpf_hdrlen(struct bpf_d *d) { int hdrlen; hdrlen = d->bd_bif->bif_hdrlen; #ifndef BURN_BRIDGES if (d->bd_tstamp == BPF_T_NONE || BPF_T_FORMAT(d->bd_tstamp) == BPF_T_MICROTIME) #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr32); else #endif hdrlen += SIZEOF_BPF_HDR(struct bpf_hdr); else #endif hdrlen += SIZEOF_BPF_HDR(struct bpf_xhdr); #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) hdrlen = BPF_WORDALIGN32(hdrlen); else #endif hdrlen = BPF_WORDALIGN(hdrlen); return (hdrlen - d->bd_bif->bif_hdrlen); } static void bpf_bintime2ts(struct bintime *bt, struct bpf_ts *ts, int tstype) { struct bintime bt2, boottimebin; struct timeval tsm; struct timespec tsn; if ((tstype & BPF_T_MONOTONIC) == 0) { bt2 = *bt; getboottimebin(&boottimebin); bintime_add(&bt2, &boottimebin); bt = &bt2; } switch (BPF_T_FORMAT(tstype)) { case BPF_T_MICROTIME: bintime2timeval(bt, &tsm); ts->bt_sec = tsm.tv_sec; ts->bt_frac = tsm.tv_usec; break; case BPF_T_NANOTIME: bintime2timespec(bt, &tsn); ts->bt_sec = tsn.tv_sec; ts->bt_frac = tsn.tv_nsec; break; case BPF_T_BINTIME: ts->bt_sec = bt->sec; ts->bt_frac = bt->frac; break; } } /* * Move the packet data from interface memory (pkt) into the * store buffer. "cpfn" is the routine called to do the actual data * transfer. bcopy is passed in to copy contiguous chunks, while * bpf_append_mbuf is passed in to copy mbuf chains. In the latter case, * pkt is really an mbuf. */ static void catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, void (*cpfn)(struct bpf_d *, caddr_t, u_int, void *, u_int), struct bintime *bt) { struct bpf_xhdr hdr; #ifndef BURN_BRIDGES struct bpf_hdr hdr_old; #ifdef COMPAT_FREEBSD32 struct bpf_hdr32 hdr32_old; #endif #endif int caplen, curlen, hdrlen, totlen; int do_wakeup = 0; int do_timestamp; int tstype; BPFD_LOCK_ASSERT(d); if (d->bd_bif == NULL) { /* Descriptor was detached in concurrent thread */ counter_u64_add(d->bd_dcount, 1); return; } /* * Detect whether user space has released a buffer back to us, and if * so, move it from being a hold buffer to a free buffer. This may * not be the best place to do it (for example, we might only want to * run this check if we need the space), but for now it's a reliable * spot to do it. */ if (d->bd_fbuf == NULL && bpf_canfreebuf(d)) { d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; bpf_buf_reclaimed(d); } /* * Figure out how many bytes to move. If the packet is * greater or equal to the snapshot length, transfer that * much. Otherwise, transfer the whole packet (unless * we hit the buffer size limit). */ hdrlen = bpf_hdrlen(d); totlen = hdrlen + min(snaplen, pktlen); if (totlen > d->bd_bufsize) totlen = d->bd_bufsize; /* * Round up the end of the previous packet to the next longword. * * Drop the packet if there's no room and no hope of room * If the packet would overflow the storage buffer or the storage * buffer is considered immutable by the buffer model, try to rotate * the buffer and wakeup pending processes. */ #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) curlen = BPF_WORDALIGN32(d->bd_slen); else #endif curlen = BPF_WORDALIGN(d->bd_slen); if (curlen + totlen > d->bd_bufsize || !bpf_canwritebuf(d)) { if (d->bd_fbuf == NULL) { /* * There's no room in the store buffer, and no * prospect of room, so drop the packet. Notify the * buffer model. */ bpf_buffull(d); counter_u64_add(d->bd_dcount, 1); return; } KASSERT(!d->bd_hbuf_in_use, ("hold buffer is in use")); ROTATE_BUFFERS(d); do_wakeup = 1; curlen = 0; } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) /* * Immediate mode is set, or the read timeout has already * expired during a select call. A packet arrived, so the * reader should be woken up. */ do_wakeup = 1; caplen = totlen - hdrlen; tstype = d->bd_tstamp; do_timestamp = tstype != BPF_T_NONE; #ifndef BURN_BRIDGES if (tstype == BPF_T_NONE || BPF_T_FORMAT(tstype) == BPF_T_MICROTIME) { struct bpf_ts ts; if (do_timestamp) bpf_bintime2ts(bt, &ts, tstype); #ifdef COMPAT_FREEBSD32 if (d->bd_compat32) { bzero(&hdr32_old, sizeof(hdr32_old)); if (do_timestamp) { hdr32_old.bh_tstamp.tv_sec = ts.bt_sec; hdr32_old.bh_tstamp.tv_usec = ts.bt_frac; } hdr32_old.bh_datalen = pktlen; hdr32_old.bh_hdrlen = hdrlen; hdr32_old.bh_caplen = caplen; bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr32_old, sizeof(hdr32_old)); goto copy; } #endif bzero(&hdr_old, sizeof(hdr_old)); if (do_timestamp) { hdr_old.bh_tstamp.tv_sec = ts.bt_sec; hdr_old.bh_tstamp.tv_usec = ts.bt_frac; } hdr_old.bh_datalen = pktlen; hdr_old.bh_hdrlen = hdrlen; hdr_old.bh_caplen = caplen; bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr_old, sizeof(hdr_old)); goto copy; } #endif /* * Append the bpf header. Note we append the actual header size, but * move forward the length of the header plus padding. */ bzero(&hdr, sizeof(hdr)); if (do_timestamp) bpf_bintime2ts(bt, &hdr.bh_tstamp, tstype); hdr.bh_datalen = pktlen; hdr.bh_hdrlen = hdrlen; hdr.bh_caplen = caplen; bpf_append_bytes(d, d->bd_sbuf, curlen, &hdr, sizeof(hdr)); /* * Copy the packet data into the store buffer and update its length. */ #ifndef BURN_BRIDGES copy: #endif (*cpfn)(d, d->bd_sbuf, curlen + hdrlen, pkt, caplen); d->bd_slen = curlen + totlen; if (do_wakeup) bpf_wakeup(d); } /* * Free buffers currently in use by a descriptor. * Called on close. */ static void bpfd_free(epoch_context_t ctx) { struct bpf_d *d; struct bpf_program_buffer *p; /* * We don't need to lock out interrupts since this descriptor has * been detached from its interface and it yet hasn't been marked * free. */ d = __containerof(ctx, struct bpf_d, epoch_ctx); bpf_free(d); if (d->bd_rfilter != NULL) { p = __containerof((void *)d->bd_rfilter, struct bpf_program_buffer, buffer); #ifdef BPF_JITTER p->func = d->bd_bfilter; #endif bpf_program_buffer_free(&p->epoch_ctx); } if (d->bd_wfilter != NULL) { p = __containerof((void *)d->bd_wfilter, struct bpf_program_buffer, buffer); #ifdef BPF_JITTER p->func = NULL; #endif bpf_program_buffer_free(&p->epoch_ctx); } mtx_destroy(&d->bd_lock); counter_u64_free(d->bd_rcount); counter_u64_free(d->bd_dcount); counter_u64_free(d->bd_fcount); counter_u64_free(d->bd_wcount); counter_u64_free(d->bd_wfcount); counter_u64_free(d->bd_wdcount); counter_u64_free(d->bd_zcopy); free(d, M_BPF); } /* * Attach an interface to bpf. dlt is the link layer type; hdrlen is the * fixed size of the link header (variable length headers not yet supported). */ void bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) { bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); } /* * Attach an interface to bpf. ifp is a pointer to the structure * defining the interface to be attached, dlt is the link layer type, * and hdrlen is the fixed size of the link header (variable length * headers are not yet supporrted). */ void bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) { struct bpf_if *bp; KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); bp = malloc(sizeof(*bp), M_BPF, M_WAITOK | M_ZERO); CK_LIST_INIT(&bp->bif_dlist); CK_LIST_INIT(&bp->bif_wlist); bp->bif_ifp = ifp; bp->bif_dlt = dlt; bp->bif_hdrlen = hdrlen; bp->bif_bpf = driverp; bp->bif_refcnt = 1; *driverp = bp; /* * Reference ifnet pointer, so it won't freed until * we release it. */ if_ref(ifp); BPF_LOCK(); CK_LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); BPF_UNLOCK(); if (bootverbose && IS_DEFAULT_VNET(curvnet)) if_printf(ifp, "bpf attached\n"); } #ifdef VIMAGE /* * When moving interfaces between vnet instances we need a way to * query the dlt and hdrlen before detach so we can re-attch the if_bpf * after the vmove. We unfortunately have no device driver infrastructure * to query the interface for these values after creation/attach, thus * add this as a workaround. */ int bpf_get_bp_params(struct bpf_if *bp, u_int *bif_dlt, u_int *bif_hdrlen) { if (bp == NULL) return (ENXIO); if (bif_dlt == NULL && bif_hdrlen == NULL) return (0); if (bif_dlt != NULL) *bif_dlt = bp->bif_dlt; if (bif_hdrlen != NULL) *bif_hdrlen = bp->bif_hdrlen; return (0); } #endif /* * Detach bpf from an interface. This involves detaching each descriptor * associated with the interface. Notify each descriptor as it's detached * so that any sleepers wake up and get ENXIO. */ void bpfdetach(struct ifnet *ifp) { struct bpf_if *bp, *bp_temp; struct bpf_d *d; BPF_LOCK(); /* Find all bpf_if struct's which reference ifp and detach them. */ CK_LIST_FOREACH_SAFE(bp, &bpf_iflist, bif_next, bp_temp) { if (ifp != bp->bif_ifp) continue; CK_LIST_REMOVE(bp, bif_next); *bp->bif_bpf = (struct bpf_if *)&dead_bpf_if; CTR4(KTR_NET, "%s: sheduling free for encap %d (%p) for if %p", __func__, bp->bif_dlt, bp, ifp); /* Detach common descriptors */ while ((d = CK_LIST_FIRST(&bp->bif_dlist)) != NULL) { bpf_detachd_locked(d, true); } /* Detach writer-only descriptors */ while ((d = CK_LIST_FIRST(&bp->bif_wlist)) != NULL) { bpf_detachd_locked(d, true); } bpfif_rele(bp); } BPF_UNLOCK(); } /* * Get a list of available data link type of the interface. */ static int bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) { struct ifnet *ifp; struct bpf_if *bp; u_int *lst; int error, n, n1; BPF_LOCK_ASSERT(); ifp = d->bd_bif->bif_ifp; n1 = 0; CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp == ifp) n1++; } if (bfl->bfl_list == NULL) { bfl->bfl_len = n1; return (0); } if (n1 > bfl->bfl_len) return (ENOMEM); lst = malloc(n1 * sizeof(u_int), M_TEMP, M_WAITOK); n = 0; CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp != ifp) continue; lst[n++] = bp->bif_dlt; } error = copyout(lst, bfl->bfl_list, sizeof(u_int) * n); free(lst, M_TEMP); bfl->bfl_len = n; return (error); } /* * Set the data link type of a BPF instance. */ static int bpf_setdlt(struct bpf_d *d, u_int dlt) { int error, opromisc; struct ifnet *ifp; struct bpf_if *bp; BPF_LOCK_ASSERT(); MPASS(d->bd_bif != NULL); /* * It is safe to check bd_bif without BPFD_LOCK, it can not be * changed while we hold global lock. */ if (d->bd_bif->bif_dlt == dlt) return (0); ifp = d->bd_bif->bif_ifp; CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) break; } if (bp == NULL) return (EINVAL); opromisc = d->bd_promisc; bpf_attachd(d, bp); if (opromisc) { error = ifpromisc(bp->bif_ifp, 1); if (error) if_printf(bp->bif_ifp, "%s: ifpromisc failed (%d)\n", __func__, error); else d->bd_promisc = 1; } return (0); } static void bpf_drvinit(void *unused) { struct cdev *dev; sx_init(&bpf_sx, "bpf global lock"); CK_LIST_INIT(&bpf_iflist); dev = make_dev(&bpf_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "bpf"); /* For compatibility */ make_dev_alias(dev, "bpf0"); } /* * Zero out the various packet counters associated with all of the bpf * descriptors. At some point, we will probably want to get a bit more * granular and allow the user to specify descriptors to be zeroed. */ static void bpf_zero_counters(void) { struct bpf_if *bp; struct bpf_d *bd; BPF_LOCK(); /* * We are protected by global lock here, interfaces and * descriptors can not be deleted while we hold it. */ CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { counter_u64_zero(bd->bd_rcount); counter_u64_zero(bd->bd_dcount); counter_u64_zero(bd->bd_fcount); counter_u64_zero(bd->bd_wcount); counter_u64_zero(bd->bd_wfcount); counter_u64_zero(bd->bd_zcopy); } } BPF_UNLOCK(); } /* * Fill filter statistics */ static void bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) { BPF_LOCK_ASSERT(); bzero(d, sizeof(*d)); d->bd_structsize = sizeof(*d); d->bd_immediate = bd->bd_immediate; d->bd_promisc = bd->bd_promisc; d->bd_hdrcmplt = bd->bd_hdrcmplt; d->bd_direction = bd->bd_direction; d->bd_feedback = bd->bd_feedback; d->bd_async = bd->bd_async; d->bd_rcount = counter_u64_fetch(bd->bd_rcount); d->bd_dcount = counter_u64_fetch(bd->bd_dcount); d->bd_fcount = counter_u64_fetch(bd->bd_fcount); d->bd_sig = bd->bd_sig; d->bd_slen = bd->bd_slen; d->bd_hlen = bd->bd_hlen; d->bd_bufsize = bd->bd_bufsize; d->bd_pid = bd->bd_pid; strlcpy(d->bd_ifname, bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); d->bd_locked = bd->bd_locked; d->bd_wcount = counter_u64_fetch(bd->bd_wcount); d->bd_wdcount = counter_u64_fetch(bd->bd_wdcount); d->bd_wfcount = counter_u64_fetch(bd->bd_wfcount); d->bd_zcopy = counter_u64_fetch(bd->bd_zcopy); d->bd_bufmode = bd->bd_bufmode; } /* * Handle `netstat -B' stats request */ static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) { static const struct xbpf_d zerostats; struct xbpf_d *xbdbuf, *xbd, tempstats; int index, error; struct bpf_if *bp; struct bpf_d *bd; /* * XXX This is not technically correct. It is possible for non * privileged users to open bpf devices. It would make sense * if the users who opened the devices were able to retrieve * the statistics for them, too. */ error = priv_check(req->td, PRIV_NET_BPF); if (error) return (error); /* * Check to see if the user is requesting that the counters be * zeroed out. Explicitly check that the supplied data is zeroed, * as we aren't allowing the user to set the counters currently. */ if (req->newptr != NULL) { if (req->newlen != sizeof(tempstats)) return (EINVAL); memset(&tempstats, 0, sizeof(tempstats)); error = SYSCTL_IN(req, &tempstats, sizeof(tempstats)); if (error) return (error); if (bcmp(&tempstats, &zerostats, sizeof(tempstats)) != 0) return (EINVAL); bpf_zero_counters(); return (0); } if (req->oldptr == NULL) return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); if (bpf_bpfd_cnt == 0) return (SYSCTL_OUT(req, 0, 0)); xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); BPF_LOCK(); if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { BPF_UNLOCK(); free(xbdbuf, M_BPF); return (ENOMEM); } index = 0; CK_LIST_FOREACH(bp, &bpf_iflist, bif_next) { /* Send writers-only first */ CK_LIST_FOREACH(bd, &bp->bif_wlist, bd_next) { xbd = &xbdbuf[index++]; bpfstats_fill_xbpf(xbd, bd); } CK_LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { xbd = &xbdbuf[index++]; bpfstats_fill_xbpf(xbd, bd); } } BPF_UNLOCK(); error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); free(xbdbuf, M_BPF); return (error); } SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL); #else /* !DEV_BPF && !NETGRAPH_BPF */ /* * NOP stubs to allow bpf-using drivers to load and function. * * A 'better' implementation would allow the core bpf functionality * to be loaded at runtime. */ void bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) { } void bpf_mtap(struct bpf_if *bp, struct mbuf *m) { } void bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) { } void bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) { bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); } void bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) { *driverp = (struct bpf_if *)&dead_bpf_if; } void bpfdetach(struct ifnet *ifp) { } u_int bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) { return -1; /* "no filter" behaviour */ } int bpf_validate(const struct bpf_insn *f, int len) { return 0; /* false */ } #endif /* !DEV_BPF && !NETGRAPH_BPF */ #ifdef DDB static void bpf_show_bpf_if(struct bpf_if *bpf_if) { if (bpf_if == NULL) return; db_printf("%p:\n", bpf_if); #define BPF_DB_PRINTF(f, e) db_printf(" %s = " f "\n", #e, bpf_if->e); /* bif_ext.bif_next */ /* bif_ext.bif_dlist */ BPF_DB_PRINTF("%#x", bif_dlt); BPF_DB_PRINTF("%u", bif_hdrlen); /* bif_wlist */ BPF_DB_PRINTF("%p", bif_ifp); BPF_DB_PRINTF("%p", bif_bpf); BPF_DB_PRINTF("%u", bif_refcnt); } DB_SHOW_COMMAND(bpf_if, db_show_bpf_if) { if (!have_addr) { db_printf("usage: show bpf_if \n"); return; } bpf_show_bpf_if((struct bpf_if *)addr); } #endif