Index: head/sbin/casperd/casperd.8 =================================================================== --- head/sbin/casperd/casperd.8 (revision 289203) +++ head/sbin/casperd/casperd.8 (revision 289204) @@ -1,126 +1,132 @@ .\" Copyright (c) 2013 The FreeBSD Foundation .\" All rights reserved. .\" .\" This documentation was written by Pawel Jakub Dawidek under sponsorship .\" from the FreeBSD Foundation. .\" .\" 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 BY THE AUTHORS 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 AUTHORS 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 October 26, 2013 .Dt CASPERD 8 .Os .Sh NAME .Nm casperd .Nd "Capability Services friendly daemon" .Sh SYNOPSIS .Nm -[-Fhv] [-D servconfdir] [-P pidfile] [-S sockpath] .Op Fl Fhv +.Op Fl l Ar listenqueue .Op Fl D Ar servconfdir .Op Fl P Ar pidfile .Op Fl S Ar sockpath .Sh DESCRIPTION The .Nm daemon hosts various services that can be accessed through libcapsicum's capabilities by programs running in sandboxes. For example it is prohibited to send UDP packets to arbitrary destinations when operating in capability mode, which makes DNS resolution impossible. To make it possible the .Nm daemon provides the .Nm system.dns service that proxies DNS resolution requests through a dedicated, non-sandboxed process provided by .Nm . .Pp The .Nm daemon can be started with the following command line arguments: .Bl -tag -width ".Fl D Ar servconfdir" .It Fl D Ar servconfdir Specify alternative location of the service configuration directory. The default location is .Pa /etc/casper/ . .It Fl F Start the .Nm daemon in the foreground. By default .Nm starts in the background. .It Fl h Print the .Nm usage message. +.It Fl l Ar listenqueue +Specify depth of socket listen queue for the +.Nm +daemon. +The default queue length is +.Pa SOMAXCONN . .It Fl P Ar pidfile Specify alternative location of a file where main process PID will be stored. The default location is .Pa /var/run/casperd.pid . .It Fl S Ar sockpath Specify alternative location of the .Xr unix 4 domain socket used to connect to the .Nm daemon. The default location is .Pa /var/run/casper . .It Fl v Print or log verbose/debugging information. This option can be specified multiple times to raise the verbosity level. .El .Sh FILES .Bl -tag -width ".Pa /var/run/casperd.pid" -compact .It Pa /etc/casper/ The configuration directory for .Nm services. .It Pa /var/run/casper .Xr unix 4 domain socket used to connect to the .Nm daemon. .It Pa /var/run/casperd.pid The default location of the .Nm PID file. .El .Sh EXIT STATUS The .Nm daemon exits 0 on success, and >0 if an error occurs. .Sh SEE ALSO .Xr cap_enter 2 , .Xr libcapsicum 3 , .Xr pidfile 3 , .Xr capsicum 4 , .Xr unix 4 .Sh AUTHORS The .Nm was implemented by .An Pawel Jakub Dawidek Aq Mt pawel@dawidek.net under sponsorship from the FreeBSD Foundation. Index: head/sbin/casperd/casperd.c =================================================================== --- head/sbin/casperd/casperd.c (revision 289203) +++ head/sbin/casperd/casperd.c (revision 289204) @@ -1,715 +1,721 @@ /*- * Copyright (c) 2012 The FreeBSD Foundation * All rights reserved. * * This software was developed by Pawel Jakub Dawidek under sponsorship from * the FreeBSD Foundation. * * 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 BY THE AUTHORS 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 AUTHORS 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. */ #include __FBSDID("$FreeBSD$"); #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 #include #include "msgio.h" #include "zygote.h" #define CASPERD_PIDFILE "/var/run/casperd.pid" #define CASPERD_SERVCONFDIR "/etc/casper" #define CASPERD_SOCKPATH "/var/run/casper" typedef void service_function_t(struct service_connection *, const nvlist_t *, nvlist_t *); struct casper_service { const char *cs_name; const char *cs_execpath; struct service *cs_service; nvlist_t *cs_attrs; TAILQ_ENTRY(casper_service) cs_next; }; static TAILQ_HEAD(, casper_service) casper_services = TAILQ_HEAD_INITIALIZER(casper_services); #define SERVICE_IS_CORE(service) ((service)->cs_execpath == NULL) static void service_external_execute(int chanfd); #define KEEP_ERRNO(work) do { \ int _serrno; \ \ _serrno = errno; \ work; \ errno = _serrno; \ } while (0) static struct casper_service * service_find(const char *name) { struct casper_service *casserv; TAILQ_FOREACH(casserv, &casper_services, cs_next) { if (strcmp(casserv->cs_name, name) == 0) break; } return (casserv); } /* * Function always consumes the given attrs. */ static void service_register(nvlist_t *attrs) { struct casper_service *casserv; const char *name; PJDLOG_ASSERT(nvlist_exists_string(attrs, "name")); PJDLOG_ASSERT(nvlist_exists_string(attrs, "execpath") || (nvlist_exists_number(attrs, "commandfunc") && nvlist_exists_number(attrs, "limitfunc"))); name = nvlist_get_string(attrs, "name"); PJDLOG_ASSERT(name != NULL); if (name[0] == '\0') { pjdlog_error("Unable to register service with an empty name."); nvlist_destroy(attrs); return; } if (service_find(name) != NULL) { pjdlog_error("Service \"%s\" is already registered.", name); nvlist_destroy(attrs); return; } casserv = malloc(sizeof(*casserv)); if (casserv == NULL) { pjdlog_errno(LOG_ERR, "Unable to register service \"%s\"", name); nvlist_destroy(attrs); return; } casserv->cs_name = name; if (nvlist_exists_string(attrs, "execpath")) { struct stat sb; PJDLOG_ASSERT(!nvlist_exists_number(attrs, "commandfunc")); PJDLOG_ASSERT(!nvlist_exists_number(attrs, "limitfunc")); casserv->cs_service = NULL; casserv->cs_execpath = nvlist_get_string(attrs, "execpath"); if (casserv->cs_execpath == NULL || casserv->cs_execpath[0] == '\0') { pjdlog_error("Unable to register service with an empty execpath."); free(casserv); nvlist_destroy(attrs); return; } if (stat(casserv->cs_execpath, &sb) == -1) { pjdlog_errno(LOG_ERR, "Unable to register service \"%s\", problem with executable \"%s\"", name, casserv->cs_execpath); free(casserv); nvlist_destroy(attrs); return; } } else /* if (nvlist_exists_number(attrs, "commandfunc")) */ { PJDLOG_ASSERT(!nvlist_exists_string(attrs, "execpath")); casserv->cs_execpath = NULL; casserv->cs_service = service_alloc(name, (void *)(uintptr_t)nvlist_get_number(attrs, "limitfunc"), (void *)(uintptr_t)nvlist_get_number(attrs, "commandfunc")); if (casserv->cs_service == NULL) { pjdlog_errno(LOG_ERR, "Unable to register service \"%s\"", name); free(casserv); nvlist_destroy(attrs); return; } } casserv->cs_attrs = attrs; TAILQ_INSERT_TAIL(&casper_services, casserv, cs_next); pjdlog_debug(1, "Service %s successfully registered.", casserv->cs_name); } static bool casper_allowed_service(const nvlist_t *limits, const char *service) { if (limits == NULL) return (true); if (nvlist_exists_null(limits, service)) return (true); return (false); } static int casper_limit(const nvlist_t *oldlimits, const nvlist_t *newlimits) { const char *name; int type; void *cookie; cookie = NULL; while ((name = nvlist_next(newlimits, &type, &cookie)) != NULL) { if (type != NV_TYPE_NULL) return (EINVAL); if (!casper_allowed_service(oldlimits, name)) return (ENOTCAPABLE); } return (0); } static int casper_command(const char *cmd, const nvlist_t *limits, nvlist_t *nvlin, nvlist_t *nvlout) { struct casper_service *casserv; const char *servname; nvlist_t *nvl; int chanfd, execfd, procfd, error; if (strcmp(cmd, "open") != 0) return (EINVAL); if (!nvlist_exists_string(nvlin, "service")) return (EINVAL); servname = nvlist_get_string(nvlin, "service"); casserv = service_find(servname); if (casserv == NULL) return (ENOENT); if (!casper_allowed_service(limits, servname)) return (ENOTCAPABLE); #ifdef O_EXEC_WORKING execfd = open(casserv->cs_execpath, O_EXEC); #else execfd = open(casserv->cs_execpath, O_RDONLY); #endif if (execfd < -1) { error = errno; pjdlog_errno(LOG_ERR, "Unable to open executable '%s' of service '%s'", casserv->cs_execpath, casserv->cs_name); return (error); } if (zygote_clone(service_external_execute, &chanfd, &procfd) == -1) { error = errno; close(execfd); return (error); } nvl = nvlist_create(0); nvlist_add_string(nvl, "service", casserv->cs_name); if (nvlist_exists_descriptor(nvlin, "stderrfd")) { nvlist_move_descriptor(nvl, "stderrfd", nvlist_take_descriptor(nvlin, "stderrfd")); } nvlist_move_descriptor(nvl, "execfd", execfd); nvlist_move_descriptor(nvl, "procfd", procfd); if (nvlist_send(chanfd, nvl) == -1) { error = errno; pjdlog_errno(LOG_ERR, "Unable to send nvlist"); nvlist_destroy(nvl); close(chanfd); return (error); } nvlist_destroy(nvl); nvlist_move_descriptor(nvlout, "chanfd", chanfd); return (0); } static void fdswap(int *fd0, int *fd1) { int tmpfd; PJDLOG_VERIFY((tmpfd = dup(*fd0)) != -1); PJDLOG_VERIFY(dup2(*fd1, *fd0) != -1); PJDLOG_VERIFY(dup2(tmpfd, *fd1) != -1); close(tmpfd); tmpfd = *fd0; *fd0 = *fd1; *fd1 = tmpfd; } static void fdmove(int *oldfdp, int newfd) { if (*oldfdp != newfd) { PJDLOG_VERIFY(dup2(*oldfdp, newfd) != -1); close(*oldfdp); *oldfdp = newfd; } } static void fdcloexec(int fd) { int flags; flags = fcntl(fd, F_GETFD); PJDLOG_ASSERT(flags != -1); if ((flags & FD_CLOEXEC) != 0) PJDLOG_VERIFY(fcntl(fd, F_SETFD, flags & ~FD_CLOEXEC) != -1); } static void service_register_core(void) { nvlist_t *nvl; nvl = nvlist_create(0); nvlist_add_string(nvl, "name", "core.casper"); nvlist_add_number(nvl, "limitfunc", (uint64_t)(uintptr_t)casper_limit); nvlist_add_number(nvl, "commandfunc", (uint64_t)(uintptr_t)casper_command); service_register(nvl); } static int setup_creds(int sock) { struct cmsgcred cred; if (cred_recv(sock, &cred) == -1) return (-1); if (setgroups((int)cred.cmcred_ngroups, cred.cmcred_groups) == -1) return (-1); if (setgid(cred.cmcred_groups[0]) == -1) return (-1); if (setuid(cred.cmcred_euid) == -1) return (-1); return (0); } static void service_external_execute(int chanfd) { char *service, *argv[3]; int stderrfd, execfd, procfd; nvlist_t *nvl; nvl = nvlist_recv(chanfd, 0); if (nvl == NULL) pjdlog_exit(1, "Unable to receive nvlist"); service = nvlist_take_string(nvl, "service"); PJDLOG_ASSERT(service != NULL); if (nvlist_exists_descriptor(nvl, "stderrfd")) { stderrfd = nvlist_take_descriptor(nvl, "stderrfd"); } else { stderrfd = open(_PATH_DEVNULL, O_RDWR); if (stderrfd < 0) pjdlog_exit(1, "Unable to open %s", _PATH_DEVNULL); } execfd = nvlist_take_descriptor(nvl, "execfd"); procfd = nvlist_take_descriptor(nvl, "procfd"); nvlist_destroy(nvl); /* * Move all descriptors into right slots. */ if (stderrfd != STDERR_FILENO) { if (chanfd == STDERR_FILENO) fdswap(&stderrfd, &chanfd); else if (execfd == STDERR_FILENO) fdswap(&stderrfd, &execfd); else if (procfd == STDERR_FILENO) fdswap(&stderrfd, &procfd); fdmove(&stderrfd, STDERR_FILENO); } fdcloexec(stderrfd); if (chanfd != PARENT_FILENO) { if (execfd == PARENT_FILENO) fdswap(&chanfd, &execfd); else if (procfd == PARENT_FILENO) fdswap(&chanfd, &procfd); fdmove(&chanfd, PARENT_FILENO); } fdcloexec(chanfd); if (execfd != EXECUTABLE_FILENO) { if (procfd == EXECUTABLE_FILENO) fdswap(&execfd, &procfd); fdmove(&execfd, EXECUTABLE_FILENO); } fdcloexec(execfd); if (procfd != PROC_FILENO) fdmove(&procfd, PROC_FILENO); fdcloexec(procfd); /* * Use credentials of the caller process. */ setup_creds(chanfd); argv[0] = service; asprintf(&argv[1], "%d", pjdlog_debug_get()); argv[2] = NULL; fexecve(execfd, argv, NULL); pjdlog_exit(1, "Unable to execute service %s", service); } static void service_register_external_one(const char *dirpath, int dfd, const char *filename) { char execpath[FILENAME_MAX]; nvlist_t *nvl; ssize_t done; int fd; fd = openat(dfd, filename, O_RDONLY); if (fd == -1) { pjdlog_errno(LOG_ERR, "Unable to open \"%s/%s\"", dirpath, filename); return; } done = read(fd, execpath, sizeof(execpath)); if (done == -1) { pjdlog_errno(LOG_ERR, "Unable to read content of \"%s/%s\"", dirpath, filename); close(fd); return; } close(fd); if (done == sizeof(execpath)) { pjdlog_error("Executable path too long in \"%s/%s\".", dirpath, filename); return; } execpath[done] = '\0'; while (done > 0) { if (execpath[--done] == '\n') execpath[done] = '\0'; } nvl = nvlist_create(0); nvlist_add_string(nvl, "name", filename); nvlist_add_string(nvl, "execpath", execpath); if (nvlist_error(nvl) != 0) { pjdlog_common(LOG_ERR, 0, nvlist_error(nvl), "Unable to allocate attributes for service \"%s/%s\"", dirpath, filename); nvlist_destroy(nvl); return; } service_register(nvl); /* service_register() consumed nvl. */ } static uint8_t file_type(int dfd, const char *filename) { struct stat sb; if (fstatat(dfd, filename, &sb, AT_SYMLINK_NOFOLLOW) == -1) { pjdlog_errno(LOG_ERR, "Unable to stat \"%s\"", filename); return (DT_UNKNOWN); } return (IFTODT(sb.st_mode)); } static void service_register_external(const char *dirpath) { DIR *dirp; struct dirent *dp; int dfd; dirp = opendir(dirpath); if (dirp == NULL) { pjdlog_errno(LOG_WARNING, "Unable to open \"%s\"", dirpath); return; } dfd = dirfd(dirp); PJDLOG_ASSERT(dfd >= 0); while ((dp = readdir(dirp)) != NULL) { dp->d_type = file_type(dfd, dp->d_name); /* We are only interested in regular files, skip the rest. */ if (dp->d_type != DT_REG) { pjdlog_debug(1, "File \"%s/%s\" is not a regular file, skipping.", dirpath, dp->d_name); continue; } service_register_external_one(dirpath, dfd, dp->d_name); } closedir(dirp); } static void casper_accept(int lsock) { struct casper_service *casserv; struct service_connection *sconn; int sock; sock = accept(lsock, NULL, NULL); if (sock == -1) { pjdlog_errno(LOG_ERR, "Unable to accept casper connection"); return; } casserv = service_find("core.casper"); PJDLOG_ASSERT(casserv != NULL); sconn = service_connection_add(casserv->cs_service, sock, NULL); if (sconn == NULL) { close(sock); return; } } static void -main_loop(const char *sockpath, struct pidfh *pfh) +main_loop(int lqlen, const char *sockpath, struct pidfh *pfh) { fd_set fds; struct sockaddr_un sun; struct casper_service *casserv; struct service_connection *sconn, *sconntmp; int lsock, sock, maxfd, ret; mode_t oldumask; lsock = socket(AF_UNIX, SOCK_STREAM, 0); if (lsock == -1) pjdlog_exit(1, "Unable to create socket"); (void)unlink(sockpath); bzero(&sun, sizeof(sun)); sun.sun_family = AF_UNIX; PJDLOG_VERIFY(strlcpy(sun.sun_path, sockpath, sizeof(sun.sun_path)) < sizeof(sun.sun_path)); sun.sun_len = SUN_LEN(&sun); oldumask = umask(S_IXUSR | S_IXGRP | S_IXOTH); if (bind(lsock, (struct sockaddr *)&sun, sizeof(sun)) == -1) pjdlog_exit(1, "Unable to bind to %s", sockpath); (void)umask(oldumask); - if (listen(lsock, 8) == -1) + if (listen(lsock, lqlen) == -1) pjdlog_exit(1, "Unable to listen on %s", sockpath); for (;;) { FD_ZERO(&fds); FD_SET(lsock, &fds); maxfd = lsock; TAILQ_FOREACH(casserv, &casper_services, cs_next) { /* We handle only core services. */ if (!SERVICE_IS_CORE(casserv)) continue; for (sconn = service_connection_first(casserv->cs_service); sconn != NULL; sconn = service_connection_next(sconn)) { sock = service_connection_get_sock(sconn); FD_SET(sock, &fds); maxfd = sock > maxfd ? sock : maxfd; } } maxfd++; PJDLOG_ASSERT(maxfd <= (int)FD_SETSIZE); ret = select(maxfd, &fds, NULL, NULL, NULL); PJDLOG_ASSERT(ret == -1 || ret > 0); /* select() cannot timeout */ if (ret == -1) { if (errno == EINTR) continue; KEEP_ERRNO((void)pidfile_remove(pfh)); pjdlog_exit(1, "select() failed"); } if (FD_ISSET(lsock, &fds)) casper_accept(lsock); TAILQ_FOREACH(casserv, &casper_services, cs_next) { /* We handle only core services. */ if (!SERVICE_IS_CORE(casserv)) continue; for (sconn = service_connection_first(casserv->cs_service); sconn != NULL; sconn = sconntmp) { /* * Prepare for connection to be removed from * the list on failure. */ sconntmp = service_connection_next(sconn); sock = service_connection_get_sock(sconn); if (FD_ISSET(sock, &fds)) { service_message(casserv->cs_service, sconn); } } } } } static void usage(void) { pjdlog_exitx(1, "usage: casperd [-Fhv] [-D servconfdir] [-P pidfile] [-S sockpath]"); } int main(int argc, char *argv[]) { struct pidfh *pfh; const char *pidfile, *servconfdir, *sockpath; pid_t otherpid; - int ch, debug; + int ch, debug, lqlen; bool foreground; pjdlog_init(PJDLOG_MODE_STD); debug = 0; foreground = false; + lqlen = SOMAXCONN; pidfile = CASPERD_PIDFILE; servconfdir = CASPERD_SERVCONFDIR; sockpath = CASPERD_SOCKPATH; - while ((ch = getopt(argc, argv, "D:FhP:S:v")) != -1) { + while ((ch = getopt(argc, argv, "D:Fhl:P:S:v")) != -1) { switch (ch) { case 'D': servconfdir = optarg; break; case 'F': foreground = true; break; + case 'l': + lqlen = strtol(optarg, NULL, 0); + if (lqlen < 1) + lqlen = SOMAXCONN; + break; case 'P': pidfile = optarg; break; case 'S': sockpath = optarg; break; case 'v': debug++; break; case 'h': default: usage(); } } argc -= optind; argv += optind; if (argc != 0) usage(); if (!foreground) pjdlog_mode_set(PJDLOG_MODE_SYSLOG); pjdlog_prefix_set("(casperd) "); pjdlog_debug_set(debug); if (zygote_init() < 0) pjdlog_exit(1, "Unable to create zygote process"); pfh = pidfile_open(pidfile, 0600, &otherpid); if (pfh == NULL) { if (errno == EEXIST) { pjdlog_exitx(1, "casperd already running, pid: %jd.", (intmax_t)otherpid); } pjdlog_errno(LOG_WARNING, "Cannot open or create pidfile %s", pidfile); } if (!foreground) { if (daemon(0, 0) == -1) { KEEP_ERRNO((void)pidfile_remove(pfh)); pjdlog_exit(1, "Unable to go into background"); } } /* Write PID to a file. */ if (pidfile_write(pfh) == -1) { pjdlog_errno(LOG_WARNING, "Unable to write to pidfile %s", pidfile); } else { pjdlog_debug(1, "PID stored in %s.", pidfile); } /* * Register core services. */ service_register_core(); /* * Register external services. */ service_register_external(servconfdir); /* * Wait for connections. */ - main_loop(sockpath, pfh); + main_loop(lqlen, sockpath, pfh); }