diff --git a/nc.1 b/nc.1 index 6bdfe4f90415..0ef318e0e6f5 100644 --- a/nc.1 +++ b/nc.1 @@ -1,586 +1,588 @@ -.\" $OpenBSD: nc.1,v 1.93 2018/12/27 17:45:36 jmc Exp $ +.\" $OpenBSD: nc.1,v 1.97 2022/09/11 09:58:06 schwarze Exp $ .\" .\" Copyright (c) 1996 David Sacerdote .\" 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. .\" 3. The name of the author may not be used to endorse or promote products .\" derived from this software without specific prior written permission .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. .\" -.Dd $Mdocdate: December 27 2018 $ +.Dd $Mdocdate: September 11 2022 $ .Dt NC 1 .Os .Sh NAME .Nm nc .Nd arbitrary TCP and UDP connections and listens .Sh SYNOPSIS .Nm nc .Op Fl 46cDdFhklNnrStUuvz .Op Fl C Ar certfile .Op Fl e Ar name .Op Fl H Ar hash .Op Fl I Ar length .Op Fl i Ar interval .Op Fl K Ar keyfile .Op Fl M Ar ttl .Op Fl m Ar minttl .Op Fl O Ar length .Op Fl o Ar staplefile .Op Fl P Ar proxy_username .Op Fl p Ar source_port .Op Fl R Ar CAfile -.Op Fl s Ar source +.Op Fl s Ar sourceaddr .Op Fl T Ar keyword .Op Fl V Ar rtable .Op Fl W Ar recvlimit .Op Fl w Ar timeout .Op Fl X Ar proxy_protocol .Op Fl x Ar proxy_address Ns Op : Ns Ar port .Op Fl Z Ar peercertfile .Op Ar destination .Op Ar port .Sh DESCRIPTION The .Nm (or .Nm netcat ) utility is used for just about anything under the sun involving TCP, UDP, or .Ux Ns -domain sockets. It can open TCP connections, send UDP packets, listen on arbitrary TCP and UDP ports, do port scanning, and deal with both IPv4 and IPv6. Unlike .Xr telnet 1 , .Nm scripts nicely, and separates error messages onto standard error instead of sending them to standard output, as .Xr telnet 1 does with some. .Pp Common uses include: .Pp .Bl -bullet -offset indent -compact .It simple TCP proxies .It shell-script based HTTP clients and servers .It network daemon testing .It a SOCKS or HTTP ProxyCommand for .Xr ssh 1 .It and much, much more .El .Pp The options are as follows: .Bl -tag -width Ds .It Fl 4 Use IPv4 addresses only. .It Fl 6 Use IPv6 addresses only. .It Fl C Ar certfile Load the public key part of the TLS peer certificate from .Ar certfile , in PEM format. Requires .Fl c . .It Fl c Use TLS to connect or listen. Cannot be used together with any of the options .Fl FuU . .It Fl D Enable debugging on the socket. .It Fl d Do not attempt to read from stdin. .It Fl e Ar name Only accept the TLS peer certificate if it contains the .Ar name . Requires .Fl c . If not specified, .Ar destination is used. .It Fl F Pass the first connected socket using .Xr sendmsg 2 to stdout and exit. This is useful in conjunction with .Fl X to have .Nm perform connection setup with a proxy but then leave the rest of the connection to another program (e.g.\& .Xr ssh 1 using the .Xr ssh_config 5 .Cm ProxyUseFdpass option). Cannot be used with .Fl c or .Fl U . .It Fl H Ar hash Only accept the TLS peer certificate if its hash returned from .Xr tls_peer_cert_hash 3 matches .Ar hash . Requires .Fl c and cannot be used with .Fl T Cm noverify . .It Fl h Print out the .Nm help text and exit. .It Fl I Ar length Specify the size of the TCP receive buffer. .It Fl i Ar interval Sleep for .Ar interval seconds between lines of text sent and received. Also causes a delay time between connections to multiple ports. .It Fl K Ar keyfile Load the TLS private key from .Ar keyfile , in PEM format. Requires .Fl c . .It Fl k When a connection is completed, listen for another one. Requires .Fl l . When used together with the .Fl u option, the server socket is not connected and it can receive UDP datagrams from multiple hosts. .It Fl l Listen for an incoming connection rather than initiating a connection to a remote host. Cannot be used together with any of the options .Fl psxz . Additionally, any timeouts specified with the .Fl w option are ignored. .It Fl M Ar ttl Set the TTL / hop limit of outgoing packets. .It Fl m Ar minttl Ask the kernel to drop incoming packets whose TTL / hop limit is under .Ar minttl . .It Fl N .Xr shutdown 2 the network socket after EOF on the input. Some servers require this to finish their work. .It Fl n -Do not do any DNS or service lookups on any specified addresses, -hostnames or ports. +Do not perform domain name resolution. +If a name cannot be resolved without DNS, an error will be reported. .It Fl O Ar length Specify the size of the TCP send buffer. .It Fl o Ar staplefile During the TLS handshake, load data to be stapled from .Ar staplefile , which is expected to contain an OCSP response from an OCSP server in DER format. Requires .Fl c and .Fl C . .It Fl P Ar proxy_username Specifies a username to present to a proxy server that requires authentication. If no username is specified then authentication will not be attempted. Proxy authentication is only supported for HTTP CONNECT proxies at present. .It Fl p Ar source_port Specify the source port .Nm should use, subject to privilege restrictions and availability. Cannot be used together with .Fl l . .It Fl R Ar CAfile Load the root CA bundle for TLS certificate verification from .Ar CAfile , in PEM format, instead of .Pa /etc/ssl/cert.pem . Requires .Fl c . .It Fl r Choose source and/or destination ports randomly instead of sequentially within a range or in the order that the system assigns them. .It Fl S Enable the RFC 2385 TCP MD5 signature option. -.It Fl s Ar source -Send packets from the interface with the -.Ar source -IP address. +.It Fl s Ar sourceaddr +Set the source address to send packets from, +which is useful on machines with multiple interfaces. For .Ux Ns -domain datagram sockets, specifies the local temporary socket file to create and use so that datagrams can be received. Cannot be used together with .Fl l or .Fl x . .It Fl T Ar keyword Change the IPv4 TOS/IPv6 traffic class value or the TLS options. .Pp For TLS options, .Ar keyword may be one of: .Cm noverify , which disables certificate verification; .Cm noname , which disables certificate name checking; .Cm clientcert , which requires a client certificate on incoming connections; or .Cm muststaple , which requires the peer to provide a valid stapled OCSP response with the handshake. The following TLS options specify a value in the form of a .Ar key Ns = Ns Ar value pair: .Cm ciphers , which allows the supported TLS ciphers to be specified (see .Xr tls_config_set_ciphers 3 for further details); .Cm protocols , which allows the supported TLS protocols to be specified (see .Xr tls_config_parse_protocols 3 for further details). Specifying TLS options requires .Fl c . .Pp For the IPv4 TOS/IPv6 traffic class value, .Ar keyword may be one of .Cm critical , .Cm inetcontrol , .Cm lowdelay , .Cm netcontrol , .Cm throughput , .Cm reliability , or one of the DiffServ Code Points: .Cm ef , .Cm af11 No ... Cm af43 , .Cm cs0 No ... Cm cs7 ; or a number in either hex or decimal. .It Fl t Send RFC 854 DON'T and WON'T responses to RFC 854 DO and WILL requests. This makes it possible to use .Nm to script telnet sessions. .It Fl U Use .Ux Ns -domain sockets. Cannot be used together with any of the options .Fl cFx . .It Fl u Use UDP instead of TCP. Cannot be used together with .Fl c or .Fl x . For .Ux Ns -domain sockets, use a datagram socket instead of a stream socket. If a .Ux Ns -domain socket is used, a temporary receiving socket is created in .Pa /tmp unless the .Fl s flag is given. .It Fl V Ar rtable Set the routing table to be used. .It Fl v Produce more verbose output. .It Fl W Ar recvlimit Terminate after receiving .Ar recvlimit packets from the network. .It Fl w Ar timeout Connections which cannot be established or are idle timeout after .Ar timeout seconds. The .Fl w flag has no effect on the .Fl l option, i.e.\& .Nm will listen forever for a connection, with or without the .Fl w flag. The default is no timeout. .It Fl X Ar proxy_protocol Use .Ar proxy_protocol when talking to the proxy server. Supported protocols are .Cm 4 (SOCKS v.4), .Cm 5 (SOCKS v.5) and .Cm connect (HTTPS proxy). If the protocol is not specified, SOCKS version 5 is used. .It Fl x Ar proxy_address Ns Op : Ns Ar port Connect to .Ar destination using a proxy at .Ar proxy_address and .Ar port . If .Ar port is not specified, the well-known port for the proxy protocol is used (1080 for SOCKS, 3128 for HTTPS). An IPv6 address can be specified unambiguously by enclosing .Ar proxy_address in square brackets. A proxy cannot be used with any of the options .Fl lsuU . .It Fl Z Ar peercertfile Save the peer certificates to .Ar peercertfile , in PEM format. Requires .Fl c . .It Fl z Only scan for listening daemons, without sending any data to them. Cannot be used together with .Fl l . .El .Pp .Ar destination can be a numerical IP address or a symbolic hostname (unless the .Fl n option is given). In general, a destination must be specified, unless the .Fl l option is given (in which case the local host is used). For .Ux Ns -domain sockets, a destination is required and is the socket path to connect to (or listen on if the .Fl l option is given). .Pp .Ar port can be specified as a numeric port number or as a service name. Port ranges may be specified as numeric port numbers of the form .Ar nn Ns - Ns Ar mm . In general, a destination port must be specified, unless the .Fl U option is given. .Sh CLIENT/SERVER MODEL It is quite simple to build a very basic client/server model using .Nm . On one console, start .Nm listening on a specific port for a connection. For example: .Pp .Dl $ nc -l 1234 .Pp .Nm is now listening on port 1234 for a connection. On a second console .Pq or a second machine , connect to the machine and port being listened on: .Pp -.Dl $ nc 127.0.0.1 1234 +.Dl $ nc -N 127.0.0.1 1234 .Pp There should now be a connection between the ports. Anything typed at the second console will be concatenated to the first, and vice-versa. After the connection has been set up, .Nm does not really care which side is being used as a .Sq server and which side is being used as a .Sq client . The connection may be terminated using an .Dv EOF -.Pq Sq ^D . +.Pq Sq ^D , +as the +.Fl N +flag was given. .Sh DATA TRANSFER The example in the previous section can be expanded to build a basic data transfer model. Any information input into one end of the connection will be output to the other end, and input and output can be easily captured in order to emulate file transfer. .Pp Start by using .Nm to listen on a specific port, with output captured into a file: .Pp -.Dl $ nc -l 1234 \*(Gt filename.out +.Dl $ nc -l 1234 > filename.out .Pp Using a second machine, connect to the listening .Nm process, feeding it the file which is to be transferred: .Pp -.Dl $ nc -N host.example.com 1234 \*(Lt filename.in +.Dl $ nc -N host.example.com 1234 < filename.in .Pp After the file has been transferred, the connection will close automatically. .Sh TALKING TO SERVERS It is sometimes useful to talk to servers .Dq by hand rather than through a user interface. It can aid in troubleshooting, when it might be necessary to verify what data a server is sending in response to commands issued by the client. For example, to retrieve the home page of a web site: .Bd -literal -offset indent $ printf "GET / HTTP/1.0\er\en\er\en" | nc host.example.com 80 .Ed .Pp Note that this also displays the headers sent by the web server. They can be filtered, using a tool such as .Xr sed 1 , if necessary. .Pp More complicated examples can be built up when the user knows the format of requests required by the server. As another example, an email may be submitted to an SMTP server using: .Bd -literal -offset indent -$ nc localhost 25 \*(Lt\*(Lt EOF +$ nc localhost 25 << EOF HELO host.example.com -MAIL FROM:\*(Ltuser@host.example.com\*(Gt -RCPT TO:\*(Ltuser2@host.example.com\*(Gt +MAIL FROM: +RCPT TO: DATA Body of email. \&. QUIT EOF .Ed .Sh PORT SCANNING It may be useful to know which ports are open and running services on a target machine. The .Fl z flag can be used to tell .Nm to report open ports, rather than initiate a connection. For example: .Bd -literal -offset indent $ nc -z host.example.com 20-30 Connection to host.example.com 22 port [tcp/ssh] succeeded! Connection to host.example.com 25 port [tcp/smtp] succeeded! .Ed .Pp The port range was specified to limit the search to ports 20 \- 30. .Pp Alternatively, it might be useful to know which server software is running, and which versions. This information is often contained within the greeting banners. In order to retrieve these, it is necessary to first make a connection, and then break the connection when the banner has been retrieved. This can be accomplished by specifying a small timeout with the .Fl w flag, or perhaps by issuing a .Qq Dv QUIT command to the server: .Bd -literal -offset indent $ echo "QUIT" | nc host.example.com 20-30 SSH-1.99-OpenSSH_3.6.1p2 Protocol mismatch. 220 host.example.com IMS SMTP Receiver Version 0.84 Ready .Ed .Sh EXAMPLES Open a TCP connection to port 42 of host.example.com, using port 31337 as the source port, with a timeout of 5 seconds: .Pp .Dl $ nc -p 31337 -w 5 host.example.com 42 .Pp Open a TCP connection to port 443 of www.example.com, and negotiate TLS with any supported TLS protocol version and "compat" ciphers: .Pp .Dl $ nc -cv -T protocols=all -T ciphers=compat www.example.com 443 .Pp Open a TCP connection to port 443 of www.google.ca, and negotiate TLS. Check for a different name in the certificate for validation: .Pp .Dl $ nc -cv -e adsf.au.doubleclick.net www.google.ca 443 .Pp Open a UDP connection to port 53 of host.example.com: .Pp .Dl $ nc -u host.example.com 53 .Pp Open a TCP connection to port 42 of host.example.com using 10.1.2.3 as the IP for the local end of the connection: .Pp .Dl $ nc -s 10.1.2.3 host.example.com 42 .Pp Create and listen on a .Ux Ns -domain stream socket: .Pp .Dl $ nc -lU /var/tmp/dsocket .Pp Connect to port 42 of host.example.com via an HTTP proxy at 10.2.3.4, port 8080. This example could also be used by .Xr ssh 1 ; see the .Cm ProxyCommand directive in .Xr ssh_config 5 for more information. .Pp .Dl $ nc -x10.2.3.4:8080 -Xconnect host.example.com 42 .Pp The same example again, this time enabling proxy authentication with username .Dq ruser if the proxy requires it: .Pp .Dl $ nc -x10.2.3.4:8080 -Xconnect -Pruser host.example.com 42 .Sh SEE ALSO .Xr cat 1 , .Xr ssh 1 .Sh AUTHORS Original implementation by .An *Hobbit* Aq Mt hobbit@avian.org . .br Rewritten with IPv6 support by .An Eric Jackson Aq Mt ericj@monkey.org . .Sh CAVEATS UDP port scans using the .Fl uz combination of flags will always report success irrespective of the target machine's state. However, in conjunction with a traffic sniffer either on the target machine or an intermediary device, the .Fl uz combination could be useful for communications diagnostics. Note that the amount of UDP traffic generated may be limited either due to hardware resources and/or configuration settings. diff --git a/netcat.c b/netcat.c index 048502bd1e5a..54ddd0ffccf7 100644 --- a/netcat.c +++ b/netcat.c @@ -1,1805 +1,1873 @@ -/* $OpenBSD: netcat.c,v 1.203 2019/02/26 17:32:47 jsing Exp $ */ +/* $OpenBSD: netcat.c,v 1.226 2023/08/14 08:07:27 tb Exp $ */ /* * Copyright (c) 2001 Eric Jackson * Copyright (c) 2015 Bob Beck. 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. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. */ /* * Re-written nc(1) for OpenBSD. Original implementation by * *Hobbit* . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "atomicio.h" #define PORT_MAX 65535 #define UNIX_DG_TMP_SOCKET_SIZE 19 #define POLL_STDIN 0 #define POLL_NETOUT 1 #define POLL_NETIN 2 #define POLL_STDOUT 3 #define BUFSIZE 16384 #define TLS_NOVERIFY (1 << 1) #define TLS_NONAME (1 << 2) #define TLS_CCERT (1 << 3) #define TLS_MUSTSTAPLE (1 << 4) /* Command Line Options */ int dflag; /* detached, no stdin */ int Fflag; /* fdpass sock to stdout */ unsigned int iflag; /* Interval Flag */ int kflag; /* More than one connect */ int lflag; /* Bind to local port */ int Nflag; /* shutdown() network socket */ int nflag; /* Don't do name look up */ char *Pflag; /* Proxy username */ char *pflag; /* Localport flag */ int rflag; /* Random ports flag */ char *sflag; /* Source Address */ int tflag; /* Telnet Emulation */ int uflag; /* UDP - Default to TCP */ int vflag; /* Verbosity */ int xflag; /* Socks proxy */ int zflag; /* Port Scan Flag */ int Dflag; /* sodebug */ int Iflag; /* TCP receive buffer size */ int Oflag; /* TCP send buffer size */ int Sflag; /* TCP MD5 signature option */ int Tflag = -1; /* IP Type of Service */ int rtableid = -1; int usetls; /* use TLS */ const char *Cflag; /* Public cert file */ const char *Kflag; /* Private key file */ const char *oflag; /* OCSP stapling file */ const char *Rflag; /* Root CA file */ int tls_cachanged; /* Using non-default CA file */ -int TLSopt; /* TLS options */ +int TLSopt; /* TLS options */ char *tls_expectname; /* required name in peer cert */ char *tls_expecthash; /* required hash of peer cert */ char *tls_ciphers; /* TLS ciphers */ char *tls_protocols; /* TLS protocols */ FILE *Zflag; /* file to save peer cert */ int recvcount, recvlimit; int timeout = -1; int family = AF_UNSPEC; char *portlist[PORT_MAX+1]; char *unix_dg_tmp_socket; int ttl = -1; int minttl = -1; void atelnet(int, unsigned char *, unsigned int); int strtoport(char *portstr, int udp); void build_ports(char *); void help(void) __attribute__((noreturn)); int local_listen(const char *, const char *, struct addrinfo); void readwrite(int, struct tls *); void fdpass(int nfd) __attribute__((noreturn)); -int remote_connect(const char *, const char *, struct addrinfo); +int remote_connect(const char *, const char *, struct addrinfo, char *); int timeout_tls(int, struct tls *, int (*)(struct tls *)); int timeout_connect(int, const struct sockaddr *, socklen_t); int socks_connect(const char *, const char *, struct addrinfo, const char *, const char *, struct addrinfo, int, const char *); int udptest(int); +void connection_info(const char *, const char *, const char *, const char *); int unix_bind(char *, int); int unix_connect(char *); int unix_listen(char *); void set_common_sockopts(int, int); int process_tos_opt(char *, int *); int process_tls_opt(char *, int *); void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); void report_sock(const char *, const struct sockaddr *, socklen_t, char *); void report_tls(struct tls *tls_ctx, char * host); void usage(int); ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); void tls_setup_client(struct tls *, int, char *); struct tls *tls_setup_server(struct tls *, int, char *); int main(int argc, char *argv[]) { int ch, s = -1, ret, socksv; char *host, *uport; + char ipaddr[NI_MAXHOST]; struct addrinfo hints; - struct servent *sv; socklen_t len; struct sockaddr_storage cliaddr; char *proxy = NULL, *proxyport = NULL; const char *errstr; struct addrinfo proxyhints; char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; struct tls_config *tls_cfg = NULL; struct tls *tls_ctx = NULL; uint32_t protocols; ret = 1; socksv = 5; host = NULL; uport = NULL; - sv = NULL; Rflag = tls_default_ca_cert_file(); signal(SIGPIPE, SIG_IGN); while ((ch = getopt(argc, argv, "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) != -1) { switch (ch) { case '4': family = AF_INET; break; case '6': family = AF_INET6; break; case 'U': family = AF_UNIX; break; case 'X': if (strcasecmp(optarg, "connect") == 0) socksv = -1; /* HTTP proxy CONNECT */ else if (strcmp(optarg, "4") == 0) socksv = 4; /* SOCKS v.4 */ else if (strcmp(optarg, "5") == 0) socksv = 5; /* SOCKS v.5 */ else errx(1, "unsupported proxy protocol"); break; case 'C': Cflag = optarg; break; case 'c': usetls = 1; break; case 'd': dflag = 1; break; case 'e': tls_expectname = optarg; break; case 'F': Fflag = 1; break; case 'H': tls_expecthash = optarg; break; case 'h': help(); break; case 'i': iflag = strtonum(optarg, 0, UINT_MAX, &errstr); if (errstr) errx(1, "interval %s: %s", errstr, optarg); break; case 'K': Kflag = optarg; break; case 'k': kflag = 1; break; case 'l': lflag = 1; break; case 'M': ttl = strtonum(optarg, 0, 255, &errstr); if (errstr) errx(1, "ttl is %s", errstr); break; case 'm': minttl = strtonum(optarg, 0, 255, &errstr); if (errstr) errx(1, "minttl is %s", errstr); break; case 'N': Nflag = 1; break; case 'n': nflag = 1; break; case 'P': Pflag = optarg; break; case 'p': pflag = optarg; break; case 'R': tls_cachanged = 1; Rflag = optarg; break; case 'r': rflag = 1; break; case 's': sflag = optarg; break; case 't': tflag = 1; break; case 'u': uflag = 1; break; case 'V': rtableid = (int)strtonum(optarg, 0, RT_TABLEID_MAX, &errstr); if (errstr) errx(1, "rtable %s: %s", errstr, optarg); break; case 'v': vflag = 1; break; case 'W': recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); if (errstr) errx(1, "receive limit %s: %s", errstr, optarg); break; case 'w': timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); if (errstr) errx(1, "timeout %s: %s", errstr, optarg); timeout *= 1000; break; case 'x': xflag = 1; if ((proxy = strdup(optarg)) == NULL) err(1, NULL); break; case 'Z': if (strcmp(optarg, "-") == 0) Zflag = stderr; else if ((Zflag = fopen(optarg, "w")) == NULL) err(1, "can't open %s", optarg); break; case 'z': zflag = 1; break; case 'D': Dflag = 1; break; case 'I': Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); if (errstr != NULL) errx(1, "TCP receive window %s: %s", errstr, optarg); break; case 'O': Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); if (errstr != NULL) errx(1, "TCP send window %s: %s", errstr, optarg); break; case 'o': oflag = optarg; break; case 'S': Sflag = 1; break; case 'T': errstr = NULL; errno = 0; if (process_tls_opt(optarg, &TLSopt)) break; if (process_tos_opt(optarg, &Tflag)) break; if (strlen(optarg) > 1 && optarg[0] == '0' && optarg[1] == 'x') Tflag = (int)strtol(optarg, NULL, 16); else Tflag = (int)strtonum(optarg, 0, 255, &errstr); if (Tflag < 0 || Tflag > 255 || errstr || errno) errx(1, "illegal tos/tls value %s", optarg); break; default: usage(1); } } argc -= optind; argv += optind; if (rtableid >= 0) if (setrtable(rtableid) == -1) err(1, "setrtable"); /* Cruft to make sure options are clean, and used properly. */ - if (argv[0] && !argv[1] && family == AF_UNIX) { + if (argc == 1 && family == AF_UNIX) { host = argv[0]; - uport = NULL; - } else if (argv[0] && !argv[1]) { - if (!lflag) - usage(1); + } else if (argc == 1 && lflag) { uport = argv[0]; - host = NULL; - } else if (argv[0] && argv[1]) { + } else if (argc == 2) { host = argv[0]; uport = argv[1]; } else usage(1); if (usetls) { if (Cflag && unveil(Cflag, "r") == -1) - err(1, "unveil"); + err(1, "unveil %s", Cflag); if (unveil(Rflag, "r") == -1) - err(1, "unveil"); + err(1, "unveil %s", Rflag); if (Kflag && unveil(Kflag, "r") == -1) - err(1, "unveil"); + err(1, "unveil %s", Kflag); if (oflag && unveil(oflag, "r") == -1) - err(1, "unveil"); + err(1, "unveil %s", oflag); + } else if (family == AF_UNIX && uflag && lflag && !kflag) { + /* + * After recvfrom(2) from client, the server connects + * to the client socket. As the client path is determined + * during runtime, we cannot unveil(2). + */ } else { if (family == AF_UNIX) { if (unveil(host, "rwc") == -1) - err(1, "unveil"); - if (uflag && !lflag) { - if (unveil(sflag ? sflag : "/tmp", "rwc") == -1) - err(1, "unveil"); + err(1, "unveil %s", host); + if (uflag && !kflag) { + if (sflag) { + if (unveil(sflag, "rwc") == -1) + err(1, "unveil %s", sflag); + } else { + if (unveil("/tmp", "rwc") == -1) + err(1, "unveil /tmp"); + } } } else { + /* no filesystem visibility */ if (unveil("/", "") == -1) - err(1, "unveil"); + err(1, "unveil /"); } } if (family == AF_UNIX) { if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) err(1, "pledge"); } else if (Fflag && Pflag) { if (pledge("stdio inet dns sendfd tty", NULL) == -1) err(1, "pledge"); } else if (Fflag) { if (pledge("stdio inet dns sendfd", NULL) == -1) err(1, "pledge"); } else if (Pflag && usetls) { if (pledge("stdio rpath inet dns tty", NULL) == -1) err(1, "pledge"); } else if (Pflag) { if (pledge("stdio inet dns tty", NULL) == -1) err(1, "pledge"); } else if (usetls) { if (pledge("stdio rpath inet dns", NULL) == -1) err(1, "pledge"); } else if (pledge("stdio inet dns", NULL) == -1) err(1, "pledge"); if (lflag && sflag) errx(1, "cannot use -s and -l"); if (lflag && pflag) errx(1, "cannot use -p and -l"); if (lflag && zflag) errx(1, "cannot use -z and -l"); if (!lflag && kflag) errx(1, "must use -l with -k"); if (uflag && usetls) errx(1, "cannot use -c and -u"); if ((family == AF_UNIX) && usetls) errx(1, "cannot use -c and -U"); if ((family == AF_UNIX) && Fflag) errx(1, "cannot use -F and -U"); if (Fflag && usetls) errx(1, "cannot use -c and -F"); if (TLSopt && !usetls) errx(1, "you must specify -c to use TLS options"); if (Cflag && !usetls) errx(1, "you must specify -c to use -C"); if (Kflag && !usetls) errx(1, "you must specify -c to use -K"); if (Zflag && !usetls) errx(1, "you must specify -c to use -Z"); if (oflag && !Cflag) errx(1, "you must specify -C to use -o"); if (tls_cachanged && !usetls) errx(1, "you must specify -c to use -R"); if (tls_expecthash && !usetls) errx(1, "you must specify -c to use -H"); if (tls_expectname && !usetls) errx(1, "you must specify -c to use -e"); /* Get name of temporary socket for unix datagram client */ if ((family == AF_UNIX) && uflag && !lflag) { if (sflag) { unix_dg_tmp_socket = sflag; } else { strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", UNIX_DG_TMP_SOCKET_SIZE); if (mktemp(unix_dg_tmp_socket_buf) == NULL) err(1, "mktemp"); unix_dg_tmp_socket = unix_dg_tmp_socket_buf; } } /* Initialize addrinfo structure. */ if (family != AF_UNIX) { memset(&hints, 0, sizeof(struct addrinfo)); hints.ai_family = family; hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; if (nflag) hints.ai_flags |= AI_NUMERICHOST; } if (xflag) { if (uflag) errx(1, "no proxy support for UDP mode"); if (lflag) errx(1, "no proxy support for listen"); if (family == AF_UNIX) errx(1, "no proxy support for unix sockets"); if (sflag) errx(1, "no proxy support for local source address"); if (*proxy == '[') { ++proxy; proxyport = strchr(proxy, ']'); if (proxyport == NULL) errx(1, "missing closing bracket in proxy"); *proxyport++ = '\0'; if (*proxyport == '\0') /* Use default proxy port. */ proxyport = NULL; else { if (*proxyport == ':') ++proxyport; else errx(1, "garbage proxy port delimiter"); } } else { proxyport = strrchr(proxy, ':'); if (proxyport != NULL) *proxyport++ = '\0'; } memset(&proxyhints, 0, sizeof(struct addrinfo)); proxyhints.ai_family = family; proxyhints.ai_socktype = SOCK_STREAM; proxyhints.ai_protocol = IPPROTO_TCP; if (nflag) proxyhints.ai_flags |= AI_NUMERICHOST; } if (usetls) { if ((tls_cfg = tls_config_new()) == NULL) errx(1, "unable to allocate TLS config"); if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) errx(1, "%s", tls_config_error(tls_cfg)); if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) errx(1, "%s", tls_config_error(tls_cfg)); if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) errx(1, "%s", tls_config_error(tls_cfg)); if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) errx(1, "%s", tls_config_error(tls_cfg)); if (tls_config_parse_protocols(&protocols, tls_protocols) == -1) errx(1, "invalid TLS protocols `%s'", tls_protocols); if (tls_config_set_protocols(tls_cfg, protocols) == -1) errx(1, "%s", tls_config_error(tls_cfg)); if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1) errx(1, "%s", tls_config_error(tls_cfg)); if (!lflag && (TLSopt & TLS_CCERT)) errx(1, "clientcert is only valid with -l"); if (TLSopt & TLS_NONAME) tls_config_insecure_noverifyname(tls_cfg); if (TLSopt & TLS_NOVERIFY) { if (tls_expecthash != NULL) errx(1, "-H and -T noverify may not be used " "together"); tls_config_insecure_noverifycert(tls_cfg); } if (TLSopt & TLS_MUSTSTAPLE) tls_config_ocsp_require_stapling(tls_cfg); if (Pflag) { if (pledge("stdio inet dns tty", NULL) == -1) err(1, "pledge"); } else if (pledge("stdio inet dns", NULL) == -1) err(1, "pledge"); } if (lflag) { ret = 0; if (family == AF_UNIX) { if (uflag) s = unix_bind(host, 0); else s = unix_listen(host); } if (usetls) { tls_config_verify_client_optional(tls_cfg); if ((tls_ctx = tls_server()) == NULL) errx(1, "tls server creation failed"); if (tls_configure(tls_ctx, tls_cfg) == -1) errx(1, "tls configuration failed (%s)", tls_error(tls_ctx)); } /* Allow only one connection at a time, but stay alive. */ for (;;) { if (family != AF_UNIX) { if (s != -1) close(s); s = local_listen(host, uport, hints); } - if (s < 0) + if (s == -1) err(1, NULL); if (uflag && kflag) { + if (family == AF_UNIX) { + if (pledge("stdio unix", NULL) == -1) + err(1, "pledge"); + } /* * For UDP and -k, don't connect the socket, * let it receive datagrams from multiple * socket pairs. */ readwrite(s, NULL); } else if (uflag && !kflag) { /* * For UDP and not -k, we will use recvfrom() * initially to wait for a caller, then use * the regular functions to talk to the caller. */ int rv; char buf[2048]; struct sockaddr_storage z; len = sizeof(z); rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, (struct sockaddr *)&z, &len); - if (rv < 0) + if (rv == -1) err(1, "recvfrom"); rv = connect(s, (struct sockaddr *)&z, len); - if (rv < 0) + if (rv == -1) err(1, "connect"); + if (family == AF_UNIX) { + if (pledge("stdio unix", NULL) == -1) + err(1, "pledge"); + } if (vflag) report_sock("Connection received", - (struct sockaddr *)&z, len, NULL); + (struct sockaddr *)&z, len, + family == AF_UNIX ? host : NULL); readwrite(s, NULL); } else { struct tls *tls_cctx = NULL; int connfd; len = sizeof(cliaddr); connfd = accept4(s, (struct sockaddr *)&cliaddr, &len, SOCK_NONBLOCK); if (connfd == -1) { /* For now, all errnos are fatal */ err(1, "accept"); } if (vflag) report_sock("Connection received", (struct sockaddr *)&cliaddr, len, family == AF_UNIX ? host : NULL); if ((usetls) && (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) readwrite(connfd, tls_cctx); if (!usetls) readwrite(connfd, NULL); if (tls_cctx) timeout_tls(s, tls_cctx, tls_close); close(connfd); tls_free(tls_cctx); } if (family == AF_UNIX && uflag) { - if (connect(s, NULL, 0) < 0) + if (connect(s, NULL, 0) == -1) err(1, "connect"); } if (!kflag) break; } } else if (family == AF_UNIX) { ret = 0; if ((s = unix_connect(host)) > 0) { if (!zflag) readwrite(s, NULL); close(s); } else { warn("%s", host); ret = 1; } if (uflag) unlink(unix_dg_tmp_socket); return ret; - } else { int i = 0; /* Construct the portlist[] array. */ build_ports(uport); /* Cycle through portlist, connecting to each port. */ for (s = -1, i = 0; portlist[i] != NULL; i++) { if (s != -1) close(s); tls_free(tls_ctx); tls_ctx = NULL; if (usetls) { if ((tls_ctx = tls_client()) == NULL) errx(1, "tls client creation failed"); if (tls_configure(tls_ctx, tls_cfg) == -1) errx(1, "tls configuration failed (%s)", tls_error(tls_ctx)); } if (xflag) s = socks_connect(host, portlist[i], hints, proxy, proxyport, proxyhints, socksv, Pflag); else - s = remote_connect(host, portlist[i], hints); + s = remote_connect(host, portlist[i], hints, + ipaddr); if (s == -1) continue; ret = 0; if (vflag || zflag) { + int print_info = 1; + /* For UDP, make sure we are connected. */ if (uflag) { - if (udptest(s) == -1) { + /* No info on failed or skipped test. */ + if ((print_info = udptest(s)) == -1) { ret = 1; continue; } } - - /* Don't look up port if -n. */ - if (nflag) - sv = NULL; - else { - sv = getservbyport( - ntohs(atoi(portlist[i])), - uflag ? "udp" : "tcp"); - } - - fprintf(stderr, - "Connection to %s %s port [%s/%s] " - "succeeded!\n", host, portlist[i], - uflag ? "udp" : "tcp", - sv ? sv->s_name : "*"); + if (print_info == 1) + connection_info(host, portlist[i], + uflag ? "udp" : "tcp", ipaddr); } if (Fflag) fdpass(s); else { if (usetls) tls_setup_client(tls_ctx, s, host); if (!zflag) readwrite(s, tls_ctx); if (tls_ctx) timeout_tls(s, tls_ctx, tls_close); } } } if (s != -1) close(s); tls_free(tls_ctx); tls_config_free(tls_cfg); return ret; } /* * unix_bind() * Returns a unix socket bound to the given path */ int unix_bind(char *path, int flags) { struct sockaddr_un s_un; int s, save_errno; /* Create unix domain socket. */ if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), - 0)) < 0) + 0)) == -1) return -1; memset(&s_un, 0, sizeof(struct sockaddr_un)); s_un.sun_family = AF_UNIX; if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= sizeof(s_un.sun_path)) { close(s); errno = ENAMETOOLONG; return -1; } - if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { + if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { save_errno = errno; close(s); errno = save_errno; return -1; } if (vflag) report_sock("Bound", NULL, 0, path); return s; } int timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) { struct pollfd pfd; int ret; while ((ret = (*func)(tls_ctx)) != 0) { if (ret == TLS_WANT_POLLIN) pfd.events = POLLIN; else if (ret == TLS_WANT_POLLOUT) pfd.events = POLLOUT; else break; pfd.fd = s; if ((ret = poll(&pfd, 1, timeout)) == 1) continue; else if (ret == 0) { errno = ETIMEDOUT; ret = -1; break; } else err(1, "poll failed"); } return ret; } void tls_setup_client(struct tls *tls_ctx, int s, char *host) { const char *errstr; if (tls_connect_socket(tls_ctx, s, - tls_expectname ? tls_expectname : host) == -1) { + tls_expectname ? tls_expectname : host) == -1) { errx(1, "tls connection failed (%s)", tls_error(tls_ctx)); } if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { if ((errstr = tls_error(tls_ctx)) == NULL) errstr = strerror(errno); errx(1, "tls handshake failed (%s)", errstr); } if (vflag) report_tls(tls_ctx, host); - if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && - strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) + if (tls_expecthash && (tls_peer_cert_hash(tls_ctx) == NULL || + strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0)) errx(1, "peer certificate is not %s", tls_expecthash); if (Zflag) { save_peer_cert(tls_ctx, Zflag); if (Zflag != stderr && (fclose(Zflag) != 0)) err(1, "fclose failed saving peer cert"); } } struct tls * tls_setup_server(struct tls *tls_ctx, int connfd, char *host) { struct tls *tls_cctx; const char *errstr; if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { warnx("tls accept failed (%s)", tls_error(tls_ctx)); } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { if ((errstr = tls_error(tls_cctx)) == NULL) errstr = strerror(errno); warnx("tls handshake failed (%s)", errstr); } else { int gotcert = tls_peer_cert_provided(tls_cctx); if (vflag && gotcert) report_tls(tls_cctx, host); if ((TLSopt & TLS_CCERT) && !gotcert) warnx("No client certificate provided"); - else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && - strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) + else if (gotcert && tls_expecthash && + (tls_peer_cert_hash(tls_cctx) == NULL || + strcmp(tls_expecthash, tls_peer_cert_hash(tls_cctx)) != 0)) warnx("peer certificate is not %s", tls_expecthash); else if (gotcert && tls_expectname && (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) warnx("name (%s) not found in client cert", tls_expectname); else { return tls_cctx; } } return NULL; } /* * unix_connect() * Returns a socket connected to a local unix socket. Returns -1 on failure. */ int unix_connect(char *path) { struct sockaddr_un s_un; int s, save_errno; if (uflag) { - if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) + if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) == -1) return -1; } else { - if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) + if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1) return -1; } memset(&s_un, 0, sizeof(struct sockaddr_un)); s_un.sun_family = AF_UNIX; if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= sizeof(s_un.sun_path)) { close(s); errno = ENAMETOOLONG; return -1; } - if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { + if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { save_errno = errno; close(s); errno = save_errno; return -1; } return s; - } /* * unix_listen() * Create a unix domain socket, and listen on it. */ int unix_listen(char *path) { int s; - if ((s = unix_bind(path, 0)) < 0) + if ((s = unix_bind(path, 0)) == -1) return -1; - if (listen(s, 5) < 0) { + if (listen(s, 5) == -1) { close(s); return -1; } if (vflag) report_sock("Listening", NULL, 0, path); return s; } /* * remote_connect() * Returns a socket connected to a remote host. Properly binds to a local * port or source address if needed. Returns -1 on failure. */ int -remote_connect(const char *host, const char *port, struct addrinfo hints) +remote_connect(const char *host, const char *port, struct addrinfo hints, + char *ipaddr) { struct addrinfo *res, *res0; - int s = -1, error, on = 1, save_errno; + int s = -1, error, herr, on = 1, save_errno; if ((error = getaddrinfo(host, port, &hints, &res0))) errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, port, gai_strerror(error)); for (res = res0; res; res = res->ai_next) { if ((s = socket(res->ai_family, res->ai_socktype | - SOCK_NONBLOCK, res->ai_protocol)) < 0) + SOCK_NONBLOCK, res->ai_protocol)) == -1) continue; /* Bind to a local port or source address if specified. */ if (sflag || pflag) { struct addrinfo ahints, *ares; /* try SO_BINDANY, but don't insist */ setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); memset(&ahints, 0, sizeof(struct addrinfo)); ahints.ai_family = res->ai_family; ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; ahints.ai_flags = AI_PASSIVE; if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) errx(1, "getaddrinfo: %s", gai_strerror(error)); if (bind(s, (struct sockaddr *)ares->ai_addr, - ares->ai_addrlen) < 0) + ares->ai_addrlen) == -1) err(1, "bind failed"); freeaddrinfo(ares); } set_common_sockopts(s, res->ai_family); + if (ipaddr != NULL) { + herr = getnameinfo(res->ai_addr, res->ai_addrlen, + ipaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST); + switch (herr) { + case 0: + break; + case EAI_SYSTEM: + err(1, "getnameinfo"); + default: + errx(1, "getnameinfo: %s", gai_strerror(herr)); + } + } + if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) break; - if (vflag) - warn("connect to %s port %s (%s) failed", host, port, - uflag ? "udp" : "tcp"); + + if (vflag) { + /* only print IP if there is something to report */ + if (nflag || ipaddr == NULL || + (strncmp(host, ipaddr, NI_MAXHOST) == 0)) + warn("connect to %s port %s (%s) failed", host, + port, uflag ? "udp" : "tcp"); + else + warn("connect to %s (%s) port %s (%s) failed", + host, ipaddr, port, uflag ? "udp" : "tcp"); + } save_errno = errno; close(s); errno = save_errno; s = -1; } freeaddrinfo(res0); return s; } int timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) { struct pollfd pfd; socklen_t optlen; int optval; int ret; if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { pfd.fd = s; pfd.events = POLLOUT; if ((ret = poll(&pfd, 1, timeout)) == 1) { optlen = sizeof(optval); if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, &optval, &optlen)) == 0) { errno = optval; ret = optval == 0 ? 0 : -1; } } else if (ret == 0) { errno = ETIMEDOUT; ret = -1; } else err(1, "poll failed"); } return ret; } /* * local_listen() * Returns a socket listening on a local port, binds to specified source * address. Returns -1 on failure. */ int local_listen(const char *host, const char *port, struct addrinfo hints) { struct addrinfo *res, *res0; int s = -1, ret, x = 1, save_errno; int error; /* Allow nodename to be null. */ hints.ai_flags |= AI_PASSIVE; /* * In the case of binding to a wildcard address * default to binding to an ipv4 address. */ if (host == NULL && hints.ai_family == AF_UNSPEC) hints.ai_family = AF_INET; if ((error = getaddrinfo(host, port, &hints, &res0))) errx(1, "getaddrinfo: %s", gai_strerror(error)); for (res = res0; res; res = res->ai_next) { if ((s = socket(res->ai_family, res->ai_socktype, - res->ai_protocol)) < 0) + res->ai_protocol)) == -1) continue; ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); if (ret == -1) err(1, NULL); set_common_sockopts(s, res->ai_family); if (bind(s, (struct sockaddr *)res->ai_addr, res->ai_addrlen) == 0) break; save_errno = errno; close(s); errno = save_errno; s = -1; } if (!uflag && s != -1) { - if (listen(s, 1) < 0) + if (listen(s, 1) == -1) err(1, "listen"); } if (vflag && s != -1) { struct sockaddr_storage ss; socklen_t len; len = sizeof(ss); if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) err(1, "getsockname"); report_sock(uflag ? "Bound" : "Listening", (struct sockaddr *)&ss, len, NULL); } freeaddrinfo(res0); return s; } /* * readwrite() * Loop that polls on the network file descriptor and stdin. */ void readwrite(int net_fd, struct tls *tls_ctx) { struct pollfd pfd[4]; int stdin_fd = STDIN_FILENO; int stdout_fd = STDOUT_FILENO; unsigned char netinbuf[BUFSIZE]; size_t netinbufpos = 0; unsigned char stdinbuf[BUFSIZE]; size_t stdinbufpos = 0; int n, num_fds; ssize_t ret; /* don't read from stdin if requested */ if (dflag) stdin_fd = -1; /* stdin */ pfd[POLL_STDIN].fd = stdin_fd; pfd[POLL_STDIN].events = POLLIN; /* network out */ pfd[POLL_NETOUT].fd = net_fd; pfd[POLL_NETOUT].events = 0; /* network in */ pfd[POLL_NETIN].fd = net_fd; pfd[POLL_NETIN].events = POLLIN; /* stdout */ pfd[POLL_STDOUT].fd = stdout_fd; pfd[POLL_STDOUT].events = 0; while (1) { /* both inputs are gone, buffers are empty, we are done */ if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && stdinbufpos == 0 && netinbufpos == 0) return; /* both outputs are gone, we can't continue */ if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) return; /* listen and net in gone, queues empty, done */ if (lflag && pfd[POLL_NETIN].fd == -1 && stdinbufpos == 0 && netinbufpos == 0) return; /* help says -i is for "wait between lines sent". We read and * write arbitrary amounts of data, and we don't want to start * scanning for newlines, so this is as good as it gets */ if (iflag) sleep(iflag); /* poll */ num_fds = poll(pfd, 4, timeout); /* treat poll errors */ if (num_fds == -1) err(1, "polling error"); /* timeout happened */ if (num_fds == 0) return; /* treat socket error conditions */ for (n = 0; n < 4; n++) { if (pfd[n].revents & (POLLERR|POLLNVAL)) { pfd[n].fd = -1; } } /* reading is possible after HUP */ if (pfd[POLL_STDIN].events & POLLIN && pfd[POLL_STDIN].revents & POLLHUP && !(pfd[POLL_STDIN].revents & POLLIN)) pfd[POLL_STDIN].fd = -1; if (pfd[POLL_NETIN].events & POLLIN && pfd[POLL_NETIN].revents & POLLHUP && !(pfd[POLL_NETIN].revents & POLLIN)) pfd[POLL_NETIN].fd = -1; if (pfd[POLL_NETOUT].revents & POLLHUP) { - if (Nflag) + if (pfd[POLL_NETOUT].fd != -1 && Nflag) shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); pfd[POLL_NETOUT].fd = -1; } /* if HUP, stop watching stdout */ if (pfd[POLL_STDOUT].revents & POLLHUP) pfd[POLL_STDOUT].fd = -1; /* if no net out, stop watching stdin */ if (pfd[POLL_NETOUT].fd == -1) pfd[POLL_STDIN].fd = -1; /* if no stdout, stop watching net in */ if (pfd[POLL_STDOUT].fd == -1) { if (pfd[POLL_NETIN].fd != -1) shutdown(pfd[POLL_NETIN].fd, SHUT_RD); pfd[POLL_NETIN].fd = -1; } /* try to read from stdin */ if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, &stdinbufpos, NULL); if (ret == TLS_WANT_POLLIN) pfd[POLL_STDIN].events = POLLIN; else if (ret == TLS_WANT_POLLOUT) pfd[POLL_STDIN].events = POLLOUT; else if (ret == 0 || ret == -1) pfd[POLL_STDIN].fd = -1; /* read something - poll net out */ if (stdinbufpos > 0) pfd[POLL_NETOUT].events = POLLOUT; /* filled buffer - remove self from polling */ if (stdinbufpos == BUFSIZE) pfd[POLL_STDIN].events = 0; } /* try to write to network */ if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, &stdinbufpos, tls_ctx); if (ret == TLS_WANT_POLLIN) pfd[POLL_NETOUT].events = POLLIN; else if (ret == TLS_WANT_POLLOUT) pfd[POLL_NETOUT].events = POLLOUT; else if (ret == -1) pfd[POLL_NETOUT].fd = -1; /* buffer empty - remove self from polling */ if (stdinbufpos == 0) pfd[POLL_NETOUT].events = 0; /* buffer no longer full - poll stdin again */ if (stdinbufpos < BUFSIZE) pfd[POLL_STDIN].events = POLLIN; } /* try to read from network */ if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, &netinbufpos, tls_ctx); if (ret == TLS_WANT_POLLIN) pfd[POLL_NETIN].events = POLLIN; else if (ret == TLS_WANT_POLLOUT) pfd[POLL_NETIN].events = POLLOUT; else if (ret == -1) pfd[POLL_NETIN].fd = -1; /* eof on net in - remove from pfd */ if (ret == 0) { shutdown(pfd[POLL_NETIN].fd, SHUT_RD); pfd[POLL_NETIN].fd = -1; } if (recvlimit > 0 && ++recvcount >= recvlimit) { if (pfd[POLL_NETIN].fd != -1) shutdown(pfd[POLL_NETIN].fd, SHUT_RD); pfd[POLL_NETIN].fd = -1; pfd[POLL_STDIN].fd = -1; } /* read something - poll stdout */ if (netinbufpos > 0) pfd[POLL_STDOUT].events = POLLOUT; /* filled buffer - remove self from polling */ if (netinbufpos == BUFSIZE) pfd[POLL_NETIN].events = 0; /* handle telnet */ - if (tflag) + if (pfd[POLL_NETIN].fd != -1 && tflag) atelnet(pfd[POLL_NETIN].fd, netinbuf, netinbufpos); } /* try to write to stdout */ if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, &netinbufpos, NULL); if (ret == TLS_WANT_POLLIN) pfd[POLL_STDOUT].events = POLLIN; else if (ret == TLS_WANT_POLLOUT) pfd[POLL_STDOUT].events = POLLOUT; else if (ret == -1) pfd[POLL_STDOUT].fd = -1; /* buffer empty - remove self from polling */ if (netinbufpos == 0) pfd[POLL_STDOUT].events = 0; /* buffer no longer full - poll net in again */ if (netinbufpos < BUFSIZE) pfd[POLL_NETIN].events = POLLIN; } /* stdin gone and queue empty? */ if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { if (pfd[POLL_NETOUT].fd != -1 && Nflag) shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); pfd[POLL_NETOUT].fd = -1; } /* net in gone and queue empty? */ if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { pfd[POLL_STDOUT].fd = -1; } } } ssize_t drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) { ssize_t n; ssize_t adjust; + if (fd == -1) + return -1; + if (tls) { n = tls_write(tls, buf, *bufpos); if (n == -1) errx(1, "tls write failed (%s)", tls_error(tls)); } else { n = write(fd, buf, *bufpos); /* don't treat EAGAIN, EINTR as error */ if (n == -1 && (errno == EAGAIN || errno == EINTR)) n = TLS_WANT_POLLOUT; } if (n <= 0) return n; /* adjust buffer */ adjust = *bufpos - n; if (adjust > 0) memmove(buf, buf + n, adjust); *bufpos -= n; return n; } ssize_t fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) { size_t num = BUFSIZE - *bufpos; ssize_t n; + if (fd == -1) + return -1; + if (tls) { n = tls_read(tls, buf + *bufpos, num); if (n == -1) errx(1, "tls read failed (%s)", tls_error(tls)); } else { n = read(fd, buf + *bufpos, num); /* don't treat EAGAIN, EINTR as error */ if (n == -1 && (errno == EAGAIN || errno == EINTR)) n = TLS_WANT_POLLIN; } if (n <= 0) return n; *bufpos += n; return n; } /* * fdpass() * Pass the connected file descriptor to stdout and exit. */ void fdpass(int nfd) { struct msghdr mh; union { struct cmsghdr hdr; char buf[CMSG_SPACE(sizeof(int))]; } cmsgbuf; struct cmsghdr *cmsg; struct iovec iov; char c = '\0'; ssize_t r; struct pollfd pfd; /* Avoid obvious stupidity */ if (isatty(STDOUT_FILENO)) errx(1, "Cannot pass file descriptor to tty"); memset(&mh, 0, sizeof(mh)); memset(&cmsgbuf, 0, sizeof(cmsgbuf)); memset(&iov, 0, sizeof(iov)); mh.msg_control = (caddr_t)&cmsgbuf.buf; mh.msg_controllen = sizeof(cmsgbuf.buf); cmsg = CMSG_FIRSTHDR(&mh); cmsg->cmsg_len = CMSG_LEN(sizeof(int)); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; *(int *)CMSG_DATA(cmsg) = nfd; iov.iov_base = &c; iov.iov_len = 1; mh.msg_iov = &iov; mh.msg_iovlen = 1; memset(&pfd, 0, sizeof(pfd)); pfd.fd = STDOUT_FILENO; pfd.events = POLLOUT; for (;;) { r = sendmsg(STDOUT_FILENO, &mh, 0); if (r == -1) { if (errno == EAGAIN || errno == EINTR) { if (poll(&pfd, 1, -1) == -1) err(1, "poll"); continue; } err(1, "sendmsg"); } else if (r != 1) errx(1, "sendmsg: unexpected return value %zd", r); else break; } exit(0); } /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ void atelnet(int nfd, unsigned char *buf, unsigned int size) { unsigned char *p, *end; unsigned char obuf[4]; if (size < 3) return; end = buf + size - 2; for (p = buf; p < end; p++) { if (*p != IAC) continue; obuf[0] = IAC; p++; if ((*p == WILL) || (*p == WONT)) obuf[1] = DONT; else if ((*p == DO) || (*p == DONT)) obuf[1] = WONT; else continue; p++; obuf[2] = *p; if (atomicio(vwrite, nfd, obuf, 3) != 3) warn("Write Error!"); } } - int strtoport(char *portstr, int udp) { struct servent *entry; const char *errstr; char *proto; int port = -1; proto = udp ? "udp" : "tcp"; port = strtonum(portstr, 1, PORT_MAX, &errstr); if (errstr == NULL) return port; if (errno != EINVAL) errx(1, "port number %s: %s", errstr, portstr); if ((entry = getservbyname(portstr, proto)) == NULL) errx(1, "service \"%s\" unknown", portstr); return ntohs(entry->s_port); } /* * build_ports() * Build an array of ports in portlist[], listing each port * that we should try to connect to. */ void build_ports(char *p) { char *n; int hi, lo, cp; int x = 0; if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) { *n = '\0'; n++; /* Make sure the ports are in order: lowest->highest. */ hi = strtoport(n, uflag); lo = strtoport(p, uflag); if (lo > hi) { cp = hi; hi = lo; lo = cp; } /* * Initialize portlist with a random permutation. Based on * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. */ if (rflag) { for (x = 0; x <= hi - lo; x++) { cp = arc4random_uniform(x + 1); portlist[x] = portlist[cp]; - if (asprintf(&portlist[cp], "%d", x + lo) < 0) + if (asprintf(&portlist[cp], "%d", x + lo) == -1) err(1, "asprintf"); } } else { /* Load ports sequentially. */ for (cp = lo; cp <= hi; cp++) { - if (asprintf(&portlist[x], "%d", cp) < 0) + if (asprintf(&portlist[x], "%d", cp) == -1) err(1, "asprintf"); x++; } } } else { char *tmp; hi = strtoport(p, uflag); if (asprintf(&tmp, "%d", hi) != -1) portlist[0] = tmp; else err(1, NULL); } } /* * udptest() * Do a few writes to see if the UDP port is there. * Fails once PF state table is full. */ int udptest(int s) { int i, ret; + /* Only write to the socket in scan mode or interactive mode. */ + if (!zflag && !isatty(STDIN_FILENO)) + return 0; + for (i = 0; i <= 3; i++) { if (write(s, "X", 1) == 1) ret = 1; else ret = -1; } return ret; } +void +connection_info(const char *host, const char *port, const char *proto, + const char *ipaddr) +{ + struct servent *sv; + char *service = "*"; + + /* Look up service name unless -n. */ + if (!nflag) { + sv = getservbyport(ntohs(atoi(port)), proto); + if (sv != NULL) + service = sv->s_name; + } + + fprintf(stderr, "Connection to %s", host); + + /* + * if we aren't connecting thru a proxy and + * there is something to report, print IP + */ + if (!nflag && !xflag && strcmp(host, ipaddr) != 0) + fprintf(stderr, " (%s)", ipaddr); + + fprintf(stderr, " %s port [%s/%s] succeeded!\n", port, proto, service); +} + void set_common_sockopts(int s, int af) { int x = 1; if (Sflag) { if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, - &x, sizeof(x)) == -1) + &x, sizeof(x)) == -1) err(1, NULL); } if (Dflag) { if (setsockopt(s, SOL_SOCKET, SO_DEBUG, - &x, sizeof(x)) == -1) + &x, sizeof(x)) == -1) err(1, NULL); } if (Tflag != -1) { if (af == AF_INET && setsockopt(s, IPPROTO_IP, IP_TOS, &Tflag, sizeof(Tflag)) == -1) err(1, "set IP ToS"); else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) err(1, "set IPv6 traffic class"); } if (Iflag) { if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &Iflag, sizeof(Iflag)) == -1) err(1, "set TCP receive buffer size"); } if (Oflag) { if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &Oflag, sizeof(Oflag)) == -1) err(1, "set TCP send buffer size"); } if (ttl != -1) { if (af == AF_INET && setsockopt(s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl))) err(1, "set IP TTL"); else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) err(1, "set IPv6 unicast hops"); } if (minttl != -1) { if (af == AF_INET && setsockopt(s, IPPROTO_IP, IP_MINTTL, &minttl, sizeof(minttl))) err(1, "set IP min TTL"); else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) err(1, "set IPv6 min hop count"); } } int process_tos_opt(char *s, int *val) { /* DiffServ Codepoints and other TOS mappings */ const struct toskeywords { const char *keyword; int val; } *t, toskeywords[] = { { "af11", IPTOS_DSCP_AF11 }, { "af12", IPTOS_DSCP_AF12 }, { "af13", IPTOS_DSCP_AF13 }, { "af21", IPTOS_DSCP_AF21 }, { "af22", IPTOS_DSCP_AF22 }, { "af23", IPTOS_DSCP_AF23 }, { "af31", IPTOS_DSCP_AF31 }, { "af32", IPTOS_DSCP_AF32 }, { "af33", IPTOS_DSCP_AF33 }, { "af41", IPTOS_DSCP_AF41 }, { "af42", IPTOS_DSCP_AF42 }, { "af43", IPTOS_DSCP_AF43 }, { "critical", IPTOS_PREC_CRITIC_ECP }, { "cs0", IPTOS_DSCP_CS0 }, { "cs1", IPTOS_DSCP_CS1 }, { "cs2", IPTOS_DSCP_CS2 }, { "cs3", IPTOS_DSCP_CS3 }, { "cs4", IPTOS_DSCP_CS4 }, { "cs5", IPTOS_DSCP_CS5 }, { "cs6", IPTOS_DSCP_CS6 }, { "cs7", IPTOS_DSCP_CS7 }, { "ef", IPTOS_DSCP_EF }, { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, { "lowdelay", IPTOS_LOWDELAY }, { "netcontrol", IPTOS_PREC_NETCONTROL }, { "reliability", IPTOS_RELIABILITY }, { "throughput", IPTOS_THROUGHPUT }, { NULL, -1 }, }; for (t = toskeywords; t->keyword != NULL; t++) { if (strcmp(s, t->keyword) == 0) { *val = t->val; return 1; } } return 0; } int process_tls_opt(char *s, int *flags) { size_t len; char *v; const struct tlskeywords { const char *keyword; int flag; char **value; } *t, tlskeywords[] = { { "ciphers", -1, &tls_ciphers }, { "clientcert", TLS_CCERT, NULL }, { "muststaple", TLS_MUSTSTAPLE, NULL }, { "noverify", TLS_NOVERIFY, NULL }, { "noname", TLS_NONAME, NULL }, { "protocols", -1, &tls_protocols }, { NULL, -1, NULL }, }; len = strlen(s); if ((v = strchr(s, '=')) != NULL) { len = v - s; v++; } for (t = tlskeywords; t->keyword != NULL; t++) { if (strlen(t->keyword) == len && strncmp(s, t->keyword, len) == 0) { if (t->value != NULL) { if (v == NULL) errx(1, "invalid tls value `%s'", s); *t->value = v; } else { *flags |= t->flag; } return 1; } } return 0; } void save_peer_cert(struct tls *tls_ctx, FILE *fp) { const char *pem; size_t plen; if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) errx(1, "Can't get peer certificate"); if (fprintf(fp, "%.*s", (int)plen, pem) < 0) err(1, "unable to save peer cert"); if (fflush(fp) != 0) err(1, "unable to flush peer cert"); } void -report_tls(struct tls * tls_ctx, char * host) +report_tls(struct tls *tls_ctx, char *host) { time_t t; const char *ocsp_url; fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); fprintf(stderr, "Peer name: %s\n", tls_expectname ? tls_expectname : host); if (tls_peer_cert_subject(tls_ctx)) fprintf(stderr, "Subject: %s\n", tls_peer_cert_subject(tls_ctx)); if (tls_peer_cert_issuer(tls_ctx)) fprintf(stderr, "Issuer: %s\n", tls_peer_cert_issuer(tls_ctx)); if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) fprintf(stderr, "Valid From: %s", ctime(&t)); if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) fprintf(stderr, "Valid Until: %s", ctime(&t)); if (tls_peer_cert_hash(tls_ctx)) fprintf(stderr, "Cert Hash: %s\n", tls_peer_cert_hash(tls_ctx)); ocsp_url = tls_peer_ocsp_url(tls_ctx); if (ocsp_url != NULL) fprintf(stderr, "OCSP URL: %s\n", ocsp_url); switch (tls_peer_ocsp_response_status(tls_ctx)) { case TLS_OCSP_RESPONSE_SUCCESSFUL: fprintf(stderr, "OCSP Stapling: %s\n", - tls_peer_ocsp_result(tls_ctx) == NULL ? "" : + tls_peer_ocsp_result(tls_ctx) == NULL ? "" : tls_peer_ocsp_result(tls_ctx)); fprintf(stderr, " response_status=%d cert_status=%d crl_reason=%d\n", tls_peer_ocsp_response_status(tls_ctx), tls_peer_ocsp_cert_status(tls_ctx), tls_peer_ocsp_crl_reason(tls_ctx)); t = tls_peer_ocsp_this_update(tls_ctx); fprintf(stderr, " this update: %s", t != -1 ? ctime(&t) : "\n"); - t = tls_peer_ocsp_next_update(tls_ctx); + t = tls_peer_ocsp_next_update(tls_ctx); fprintf(stderr, " next update: %s", t != -1 ? ctime(&t) : "\n"); - t = tls_peer_ocsp_revocation_time(tls_ctx); + t = tls_peer_ocsp_revocation_time(tls_ctx); fprintf(stderr, " revocation: %s", t != -1 ? ctime(&t) : "\n"); break; case -1: break; default: - fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", + fprintf(stderr, + "OCSP Stapling: failure - response_status %d (%s)\n", tls_peer_ocsp_response_status(tls_ctx), - tls_peer_ocsp_result(tls_ctx) == NULL ? "" : + tls_peer_ocsp_result(tls_ctx) == NULL ? "" : tls_peer_ocsp_result(tls_ctx)); break; - } } void report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, char *path) { char host[NI_MAXHOST], port[NI_MAXSERV]; int herr; int flags = NI_NUMERICSERV; if (path != NULL) { fprintf(stderr, "%s on %s\n", msg, path); return; } if (nflag) flags |= NI_NUMERICHOST; - if ((herr = getnameinfo(sa, salen, host, sizeof(host), - port, sizeof(port), flags)) != 0) { - if (herr == EAI_SYSTEM) - err(1, "getnameinfo"); - else - errx(1, "getnameinfo: %s", gai_strerror(herr)); + herr = getnameinfo(sa, salen, host, sizeof(host), port, sizeof(port), + flags); + switch (herr) { + case 0: + break; + case EAI_SYSTEM: + err(1, "getnameinfo"); + default: + errx(1, "getnameinfo: %s", gai_strerror(herr)); } fprintf(stderr, "%s on %s %s\n", msg, host, port); } void help(void) { usage(0); fprintf(stderr, "\tCommand Summary:\n\ \t-4 Use IPv4\n\ \t-6 Use IPv6\n\ \t-C certfile Public key file\n\ \t-c Use TLS\n\ \t-D Enable the debug socket option\n\ \t-d Detach from stdin\n\ \t-e name\t Required name in peer certificate\n\ \t-F Pass socket fd\n\ \t-H hash\t Hash string of peer certificate\n\ \t-h This help text\n\ \t-I length TCP receive buffer length\n\ \t-i interval Delay interval for lines sent, ports scanned\n\ \t-K keyfile Private key file\n\ \t-k Keep inbound sockets open for multiple connects\n\ \t-l Listen mode, for inbound connects\n\ \t-M ttl Outgoing TTL / Hop Limit\n\ \t-m minttl Minimum incoming TTL / Hop Limit\n\ \t-N Shutdown the network socket after EOF on stdin\n\ \t-n Suppress name/port resolutions\n\ \t-O length TCP send buffer length\n\ \t-o staplefile Staple file\n\ \t-P proxyuser\tUsername for proxy authentication\n\ \t-p port\t Specify local port for remote connects\n\ \t-R CAfile CA bundle\n\ \t-r Randomize remote ports\n\ \t-S Enable the TCP MD5 signature option\n\ - \t-s source Local source address\n\ + \t-s sourceaddr Local source address\n\ \t-T keyword TOS value or TLS options\n\ \t-t Answer TELNET negotiation\n\ \t-U Use UNIX domain socket\n\ \t-u UDP mode\n\ \t-V rtable Specify alternate routing table\n\ \t-v Verbose\n\ \t-W recvlimit Terminate after receiving a number of packets\n\ \t-w timeout Timeout for connects and final net reads\n\ \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ \t-x addr[:port]\tSpecify proxy address and port\n\ \t-Z Peer certificate file\n\ \t-z Zero-I/O mode [used for scanning]\n\ Port numbers can be individual or ranges: lo-hi [inclusive]\n"); exit(1); } void usage(int ret) { fprintf(stderr, "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " "[-H hash] [-I length]\n" "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" "\t [-o staplefile] [-P proxy_username] [-p source_port] " "[-R CAfile]\n" - "\t [-s source] [-T keyword] [-V rtable] [-W recvlimit] " + "\t [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit] " "[-w timeout]\n" "\t [-X proxy_protocol] [-x proxy_address[:port]] " "[-Z peercertfile]\n" "\t [destination] [port]\n"); if (ret) exit(1); } diff --git a/socks.c b/socks.c index 856c3e744633..7c7448c9c5ff 100644 --- a/socks.c +++ b/socks.c @@ -1,399 +1,400 @@ -/* $OpenBSD: socks.c,v 1.27 2019/01/10 12:44:54 mestre Exp $ */ +/* $OpenBSD: socks.c,v 1.31 2022/06/08 20:20:26 djm Exp $ */ /* * Copyright (c) 1999 Niklas Hallqvist. All rights reserved. * Copyright (c) 2004, 2005 Damien Miller. 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 BY THE AUTHOR ``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 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 #include #include #include #include #include #include #include #include #include #include #include #include #include "atomicio.h" #define SOCKS_PORT "1080" #define HTTP_PROXY_PORT "3128" #define HTTP_MAXHDRS 64 #define SOCKS_V5 5 #define SOCKS_V4 4 #define SOCKS_NOAUTH 0 #define SOCKS_NOMETHOD 0xff #define SOCKS_CONNECT 1 #define SOCKS_IPV4 1 #define SOCKS_DOMAIN 3 #define SOCKS_IPV6 4 -int remote_connect(const char *, const char *, struct addrinfo); +int remote_connect(const char *, const char *, struct addrinfo, char *); int socks_connect(const char *, const char *, struct addrinfo, const char *, const char *, struct addrinfo, int, const char *); static int decode_addrport(const char *h, const char *p, struct sockaddr *addr, socklen_t addrlen, int v4only, int numeric) { int r; struct addrinfo hints, *res; memset(&hints, 0, sizeof(hints)); hints.ai_family = v4only ? PF_INET : PF_UNSPEC; hints.ai_flags = numeric ? AI_NUMERICHOST : 0; hints.ai_socktype = SOCK_STREAM; r = getaddrinfo(h, p, &hints, &res); /* Don't fatal when attempting to convert a numeric address */ if (r != 0) { if (!numeric) { errx(1, "getaddrinfo(\"%.64s\", \"%.64s\"): %s", h, p, gai_strerror(r)); } return (-1); } if (addrlen < res->ai_addrlen) { freeaddrinfo(res); errx(1, "internal error: addrlen < res->ai_addrlen"); } memcpy(addr, res->ai_addr, res->ai_addrlen); freeaddrinfo(res); return (0); } static int proxy_read_line(int fd, char *buf, size_t bufsz) { size_t off; for(off = 0;;) { if (off >= bufsz) errx(1, "proxy read too long"); if (atomicio(read, fd, buf + off, 1) != 1) err(1, "proxy read"); /* Skip CR */ if (buf[off] == '\r') continue; if (buf[off] == '\n') { buf[off] = '\0'; break; } off++; } return (off); } static void getproxypass(const char *proxyuser, const char *proxyhost, char *pw, size_t pwlen) { char prompt[512]; snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ", proxyuser, proxyhost); if (readpassphrase(prompt, pw, pwlen, RPP_REQUIRE_TTY) == NULL) errx(1, "Unable to read proxy passphrase"); } /* * Error strings adapted from the generally accepted SOCKSv4 spec: * * http://ftp.icm.edu.pl/packages/socks/socks4/SOCKS4.protocol */ static const char * socks4_strerror(int e) { switch (e) { case 90: return "Succeeded"; case 91: return "Request rejected or failed"; case 92: return "SOCKS server cannot connect to identd on the client"; case 93: return "Client program and identd report different user-ids"; default: return "Unknown error"; } } /* * Error strings taken almost directly from RFC 1928. */ static const char * socks5_strerror(int e) { switch (e) { case 0: return "Succeeded"; case 1: return "General SOCKS server failure"; case 2: return "Connection not allowed by ruleset"; case 3: return "Network unreachable"; case 4: return "Host unreachable"; case 5: return "Connection refused"; case 6: return "TTL expired"; case 7: return "Command not supported"; case 8: return "Address type not supported"; default: return "Unknown error"; } } int socks_connect(const char *host, const char *port, struct addrinfo hints __attribute__ ((__unused__)), const char *proxyhost, const char *proxyport, struct addrinfo proxyhints, int socksv, const char *proxyuser) { int proxyfd, r, authretry = 0; size_t hlen, wlen; unsigned char buf[1024]; size_t cnt; struct sockaddr_storage addr; struct sockaddr_in *in4 = (struct sockaddr_in *)&addr; struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr; in_port_t serverport; if (proxyport == NULL) proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT; /* Abuse API to lookup port */ if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr, sizeof(addr), 1, 1) == -1) errx(1, "unknown port \"%.64s\"", port); serverport = in4->sin_port; again: if (authretry++ > 3) errx(1, "Too many authentication failures"); - proxyfd = remote_connect(proxyhost, proxyport, proxyhints); + proxyfd = remote_connect(proxyhost, proxyport, proxyhints, NULL); if (proxyfd < 0) return (-1); if (socksv == 5) { if (decode_addrport(host, port, (struct sockaddr *)&addr, sizeof(addr), 0, 1) == -1) addr.ss_family = 0; /* used in switch below */ /* Version 5, one method: no authentication */ buf[0] = SOCKS_V5; buf[1] = 1; buf[2] = SOCKS_NOAUTH; cnt = atomicio(vwrite, proxyfd, buf, 3); if (cnt != 3) err(1, "write failed (%zu/3)", cnt); cnt = atomicio(read, proxyfd, buf, 2); if (cnt != 2) err(1, "read failed (%zu/3)", cnt); if (buf[1] == SOCKS_NOMETHOD) errx(1, "authentication method negotiation failed"); switch (addr.ss_family) { case 0: /* Version 5, connect: domain name */ /* Max domain name length is 255 bytes */ hlen = strlen(host); if (hlen > 255) errx(1, "host name too long for SOCKS5"); buf[0] = SOCKS_V5; buf[1] = SOCKS_CONNECT; buf[2] = 0; buf[3] = SOCKS_DOMAIN; buf[4] = hlen; memcpy(buf + 5, host, hlen); memcpy(buf + 5 + hlen, &serverport, sizeof serverport); wlen = 7 + hlen; break; case AF_INET: /* Version 5, connect: IPv4 address */ buf[0] = SOCKS_V5; buf[1] = SOCKS_CONNECT; buf[2] = 0; buf[3] = SOCKS_IPV4; memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr); memcpy(buf + 8, &in4->sin_port, sizeof in4->sin_port); wlen = 10; break; case AF_INET6: /* Version 5, connect: IPv6 address */ buf[0] = SOCKS_V5; buf[1] = SOCKS_CONNECT; buf[2] = 0; buf[3] = SOCKS_IPV6; memcpy(buf + 4, &in6->sin6_addr, sizeof in6->sin6_addr); memcpy(buf + 20, &in6->sin6_port, sizeof in6->sin6_port); wlen = 22; break; default: errx(1, "internal error: silly AF"); } cnt = atomicio(vwrite, proxyfd, buf, wlen); if (cnt != wlen) err(1, "write failed (%zu/%zu)", cnt, wlen); cnt = atomicio(read, proxyfd, buf, 4); if (cnt != 4) err(1, "read failed (%zu/4)", cnt); if (buf[1] != 0) { errx(1, "connection failed, SOCKSv5 error: %s", socks5_strerror(buf[1])); } switch (buf[3]) { case SOCKS_IPV4: cnt = atomicio(read, proxyfd, buf + 4, 6); if (cnt != 6) err(1, "read failed (%zu/6)", cnt); break; case SOCKS_IPV6: cnt = atomicio(read, proxyfd, buf + 4, 18); if (cnt != 18) err(1, "read failed (%zu/18)", cnt); break; default: errx(1, "connection failed, unsupported address type"); } } else if (socksv == 4) { /* This will exit on lookup failure */ decode_addrport(host, port, (struct sockaddr *)&addr, sizeof(addr), 1, 0); /* Version 4 */ buf[0] = SOCKS_V4; buf[1] = SOCKS_CONNECT; /* connect */ memcpy(buf + 2, &in4->sin_port, sizeof in4->sin_port); memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr); buf[8] = 0; /* empty username */ wlen = 9; cnt = atomicio(vwrite, proxyfd, buf, wlen); if (cnt != wlen) err(1, "write failed (%zu/%zu)", cnt, wlen); cnt = atomicio(read, proxyfd, buf, 8); if (cnt != 8) err(1, "read failed (%zu/8)", cnt); if (buf[1] != 90) { errx(1, "connection failed, SOCKSv4 error: %s", socks4_strerror(buf[1])); } } else if (socksv == -1) { /* HTTP proxy CONNECT */ /* Disallow bad chars in hostname */ - if (strcspn(host, "\r\n\t []:") != strlen(host)) + if (strcspn(host, "\r\n\t []") != strlen(host)) errx(1, "Invalid hostname"); /* Try to be sane about numeric IPv6 addresses */ if (strchr(host, ':') != NULL) { r = snprintf(buf, sizeof(buf), "CONNECT [%s]:%d HTTP/1.0\r\n", host, ntohs(serverport)); } else { r = snprintf(buf, sizeof(buf), "CONNECT %s:%d HTTP/1.0\r\n", host, ntohs(serverport)); } - if (r == -1 || (size_t)r >= sizeof(buf)) + if (r < 0 || (size_t)r >= sizeof(buf)) errx(1, "hostname too long"); r = strlen(buf); cnt = atomicio(vwrite, proxyfd, buf, r); if (cnt != r) err(1, "write failed (%zu/%d)", cnt, r); if (authretry > 1) { char proxypass[256]; char resp[1024]; getproxypass(proxyuser, proxyhost, proxypass, sizeof proxypass); r = snprintf(buf, sizeof(buf), "%s:%s", proxyuser, proxypass); explicit_bzero(proxypass, sizeof proxypass); if (r == -1 || (size_t)r >= sizeof(buf) || b64_ntop(buf, strlen(buf), resp, sizeof(resp)) == -1) errx(1, "Proxy username/password too long"); r = snprintf(buf, sizeof(buf), "Proxy-Authorization: " "Basic %s\r\n", resp); - if (r == -1 || (size_t)r >= sizeof(buf)) + if (r < 0 || (size_t)r >= sizeof(buf)) errx(1, "Proxy auth response too long"); r = strlen(buf); if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r) err(1, "write failed (%zu/%d)", cnt, r); explicit_bzero(proxypass, sizeof proxypass); explicit_bzero(buf, sizeof buf); } /* Terminate headers */ if ((cnt = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2) err(1, "write failed (%zu/2)", cnt); /* Read status reply */ proxy_read_line(proxyfd, buf, sizeof(buf)); if (proxyuser != NULL && - strncmp(buf, "HTTP/1.0 407 ", 12) == 0) { + (strncmp(buf, "HTTP/1.0 407 ", 12) == 0 || + strncmp(buf, "HTTP/1.1 407 ", 12) == 0)) { if (authretry > 1) { fprintf(stderr, "Proxy authentication " "failed\n"); } close(proxyfd); goto again; } else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 && strncmp(buf, "HTTP/1.1 200 ", 12) != 0) errx(1, "Proxy error: \"%s\"", buf); /* Headers continue until we hit an empty line */ for (r = 0; r < HTTP_MAXHDRS; r++) { proxy_read_line(proxyfd, buf, sizeof(buf)); if (*buf == '\0') break; } if (*buf != '\0') errx(1, "Too many proxy headers received"); } else errx(1, "Unknown proxy protocol %d", socksv); return (proxyfd); }