From: Aron Xu Date: Mon, 13 Feb 2012 15:56:51 +0800 Subject: New flag '-Z' for DCCP support --- nc.1 | 4 ++- netcat.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--------- 2 files changed, 76 insertions(+), 13 deletions(-) diff --git a/nc.1 b/nc.1 index fbcc098..da37f06 100644 --- a/nc.1 +++ b/nc.1 @@ -33,7 +33,7 @@ .Nd arbitrary TCP and UDP connections and listens .Sh SYNOPSIS .Nm nc -.Op Fl 46CDdFhklNnrStUuvz +.Op Fl 46CDdFhklNnrStUuvZz .Op Fl I Ar length .Op Fl i Ar interval .Op Fl M Ar ttl @@ -288,6 +288,8 @@ An IPv6 address can be specified unambiguously by enclosing in square brackets. A proxy cannot be used with any of the options .Fl lsuU . +.It Fl Z +DCCP mode. .It Fl z Only scan for listening daemons, without sending any data to them. Cannot be used together with diff --git a/netcat.c b/netcat.c index dd893ac..1c50615 100644 --- a/netcat.c +++ b/netcat.c @@ -146,6 +146,7 @@ int rflag; /* Random ports flag */ char *sflag; /* Source Address */ int tflag; /* Telnet Emulation */ int uflag; /* UDP - Default to TCP */ +int dccpflag; /* DCCP - Default to TCP */ int vflag; /* Verbosity */ int xflag; /* Socks proxy */ int zflag; /* Port Scan Flag */ @@ -225,6 +226,7 @@ ssize_t drainbuf(int, unsigned char *, size_t *, int); ssize_t fillbuf(int, unsigned char *, size_t *); #endif +char *proto_name(int, int); static int connect_with_timeout(int, const struct sockaddr *, socklen_t, int); static void quit(int sig); @@ -261,7 +263,7 @@ main(int argc, char *argv[]) #ifdef HAVE_TLS "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:q:R:rSs:T:tUuV:vW:w:X:x:Z:z")) #else - "46CDdFhI:i:klM:m:NnO:P:p:q:rSs:T:tUuV:vW:w:X:x:z")) + "46CDdFhI:i:klM:m:NnO:P:p:q:rSs:T:tUuV:vW:w:X:x:Zz")) #endif != -1) { switch (ch) { @@ -378,6 +380,13 @@ main(int argc, char *argv[]) case 'u': uflag = 1; break; + case 'Z': +#if defined(IPPROTO_DCCP) && defined(SOCK_DCCP) + dccpflag = 1; +#else + errx(1, "no DCCP support available"); +#endif + break; case 'V': #ifdef RT_TABLEID_MAX rtableid = (int)strtonum(optarg, 0, @@ -482,6 +491,10 @@ main(int argc, char *argv[]) /* Cruft to make sure options are clean, and used properly. */ if (argc == 1 && family == AF_UNIX) { +#if defined(IPPROTO_DCCP) && defined(SOCK_DCCP) + if (dccpflag) + errx(1, "cannot use -Z and -U"); +#endif host = argv[0]; } else if (argc == 0 && lflag) { if (sflag) @@ -583,8 +596,20 @@ main(int argc, char *argv[]) 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 (uflag) { + hints.ai_socktype = SOCK_DGRAM; + hints.ai_protocol = IPPROTO_UDP; + } +#if defined(IPPROTO_DCCP) && defined(SOCK_DCCP) + else if (dccpflag) { + hints.ai_socktype = SOCK_DCCP; + hints.ai_protocol = IPPROTO_DCCP; + } +#endif + else { + hints.ai_socktype = SOCK_STREAM; + hints.ai_protocol = IPPROTO_TCP; + } if (nflag) hints.ai_flags |= AI_NUMERICHOST; } @@ -592,7 +617,10 @@ main(int argc, char *argv[]) if (xflag) { if (uflag) errx(1, "no proxy support for UDP mode"); - +#if defined(IPPROTO_DCCP) && defined(SOCK_DCCP) + if (dccpflag) + errx(1, "no proxy support for DCCP mode"); +#endif if (lflag) errx(1, "no proxy support for listen"); @@ -838,9 +866,11 @@ main(int argc, char *argv[]) continue; } } - if (print_info == 1) + if (print_info == 1) { + char *proto = proto_name(uflag, dccpflag); connection_info(host, portlist[i], - uflag ? "udp" : "tcp", ipaddr); + proto, ipaddr); + } } if (Fflag) fdpass(s); @@ -1054,6 +1084,21 @@ unix_listen(char *path) return s; } +char *proto_name(int uflag, int dccpflag) { + char *proto = NULL; + + if (uflag) + proto = "udp"; +#if defined(IPPROTO_DCCP) && defined(SOCK_DCCP) + else if (dccpflag) + proto = "dccp"; +#endif + else + proto = "tcp"; + + return proto; +} + /* * remote_connect() * Returns a socket connected to a remote host. Properly binds to a local @@ -1085,8 +1130,20 @@ remote_connect(const char *host, const char *port, struct addrinfo hints, #endif 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; + if (uflag) { + ahints.ai_socktype = SOCK_DGRAM; + ahints.ai_protocol = IPPROTO_UDP; + } +#if defined(IPPROTO_DCCP) && defined(SOCK_DCCP) + else if (dccpflag) { + hints.ai_socktype = SOCK_DCCP; + hints.ai_protocol = IPPROTO_DCCP; + } +#endif + else { + ahints.ai_socktype = SOCK_STREAM; + ahints.ai_protocol = IPPROTO_TCP; + } ahints.ai_flags = AI_PASSIVE; if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) errx(1, "getaddrinfo: %s", gai_strerror(error)); @@ -1116,16 +1173,18 @@ remote_connect(const char *host, const char *port, struct addrinfo hints, timeout)) == CONNECTION_SUCCESS) break; + char *proto = proto_name(uflag, dccpflag); + 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) %s", host, - port, uflag ? "udp" : "tcp", + port, proto, error == CONNECTION_TIMEOUT ? "timed out" : "failed"); else warn("connect to %s (%s) port %s (%s) %s", - host, ipaddr, port, uflag ? "udp" : "tcp", + host, ipaddr, port, proto, error == CONNECTION_TIMEOUT ? "timed out" : "failed"); } @@ -1742,7 +1801,8 @@ build_ports(char *p) int hi, lo, cp; int x = 0; - sv = getservbyname(p, uflag ? "udp" : "tcp"); + char *proto = proto_name(uflag, dccpflag); + sv = getservbyname(p, proto); if (sv) { if (asprintf(&portlist[0], "%d", ntohs(sv->s_port)) < 0) err(1, "asprintf"); @@ -2155,6 +2215,7 @@ help(void) \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 DCCP mode\n\ \t-z Zero-I/O mode [used for scanning]\n\ Port numbers can be individual or ranges: lo-hi [inclusive]\n"); exit(0); @@ -2164,7 +2225,7 @@ void usage(int ret) { fprintf(stderr, - "usage: nc [-46CDdFhklNnrStUuvz] [-I length] [-i interval] [-M ttl]\n" + "usage: nc [-46CDdFhklNnrStUuvZz] [-I length] [-i interval] [-M ttl]\n" "\t [-m minttl] [-O length] [-P proxy_username] [-p source_port]\n" "\t [-q seconds] [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit]\n" "\t [-w timeout] [-X proxy_protocol] [-x proxy_address[:port]]\n"