diff options
| -rw-r--r-- | include/libbb.h | 10 | ||||
| -rw-r--r-- | include/usage.h | 31 | ||||
| -rw-r--r-- | ipsvd/tcpudp.c | 2 | ||||
| -rw-r--r-- | libbb/Kbuild | 1 | ||||
| -rw-r--r-- | libbb/udp_io.c (renamed from ipsvd/udp_io.c) | 17 | ||||
| -rw-r--r-- | libbb/xconnect.c | 2 | ||||
| -rw-r--r-- | networking/Config.in | 2 | ||||
| -rw-r--r-- | networking/nc.c | 5 | ||||
| -rw-r--r-- | networking/nc_bloaty.c | 799 |
9 files changed, 857 insertions, 12 deletions
diff --git a/include/libbb.h b/include/libbb.h index e5413b1a4..91715c16a 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -334,6 +334,7 @@ enum { }; /* Create stream socket, and allocated suitable lsa * (lsa of correct size and lsa->sa.sa_family (AF_INET/AF_INET6)) */ +int xsocket_type(len_and_sockaddr **lsap, int sock_type); int xsocket_stream(len_and_sockaddr **lsap); /* Create server socket bound to bindaddr:port. bindaddr can be NULL, * numeric IP ("N.N.N.N") or numeric IPv6 address, @@ -388,6 +389,15 @@ struct hostent *xgethostbyname(const char *name); // + inet_common.c has additional IPv4-only stuff +void socket_want_pktinfo(int fd); +ssize_t send_to_from(int fd, void *buf, size_t len, int flags, + const struct sockaddr *from, const struct sockaddr *to, + socklen_t tolen); +ssize_t recv_from_to(int fd, void *buf, size_t len, int flags, + struct sockaddr *from, struct sockaddr *to, + socklen_t sa_size); + + extern char *xstrdup(const char *s); extern char *xstrndup(const char *s, int n); extern char *safe_strncpy(char *dst, const char *src, size_t size); diff --git a/include/usage.h b/include/usage.h index c729532e5..fe4cd903c 100644 --- a/include/usage.h +++ b/include/usage.h @@ -2314,6 +2314,8 @@ " or\n" \ "$ nameif -c /etc/my_mactab_file\n" \ +#if !ENABLE_DESKTOP + #if ENABLE_NC_SERVER || ENABLE_NC_EXTRA #define NC_OPTIONS_STR "\n\nOptions:" #else @@ -2356,6 +2358,35 @@ "quit\n" \ "221 foobar closing connection\n" +#else /* DESKTOP nc - much more compatible with nc 1.10 */ + +#define nc_trivial_usage \ + "[-options] hostname port - connect" \ + USE_NC_SERVER("\nnc [-options] -l -p port [hostname] [port] - listen") +#define nc_full_usage \ + USE_NC_SERVER( \ + "-l Listen mode, for inbound connects\n" \ + ) \ + "-n Do not do DNS resolution" \ + "\n-s addr Local address" \ + "\n-p port Local port" \ + "\n-u UDP mode" \ + "\n-v Verbose (cumulative: -vv)" \ + "\n-w secs Timeout for connects and final net reads" \ + USE_NC_EXTRA( \ + "\n-i sec Delay interval for lines sent" /* ", ports scanned" */ \ + "\n-o file Hex dump of traffic" \ + "\n-z Zero-I/O mode (scanning)" \ + ) \ + "\n-e prog [args] Program to exec after connect (must be last)" \ +/* "\n-r Randomize local and remote ports" */ +/* "\n-g gateway Source-routing hop point[s], up to 8" */ +/* "\n-G num Source-routing pointer: 4, 8, 12, ..." */ +/* "\nport numbers can be individual or ranges: lo-hi [inclusive]" */ + +#endif + + #define netstat_trivial_usage \ "[-laenrtuwx]" #define netstat_full_usage \ diff --git a/ipsvd/tcpudp.c b/ipsvd/tcpudp.c index d2e34e3e8..8c15d4b3e 100644 --- a/ipsvd/tcpudp.c +++ b/ipsvd/tcpudp.c @@ -33,8 +33,6 @@ #include <linux/netfilter_ipv4.h> /* wants <limits.h> */ #include "busybox.h" - -#include "udp_io.c" #include "ipsvd_perhost.h" #ifdef SSLSVD diff --git a/libbb/Kbuild b/libbb/Kbuild index a3b78ef28..bdf25da09 100644 --- a/libbb/Kbuild +++ b/libbb/Kbuild @@ -78,6 +78,7 @@ lib-y += skip_whitespace.o lib-y += speed_table.o lib-y += trim.o lib-y += u_signal_names.o +lib-y += udp_io.o lib-y += uuencode.o lib-y += vdprintf.o lib-y += verror_msg.o diff --git a/ipsvd/udp_io.c b/libbb/udp_io.c index 592d98b58..d834a237b 100644 --- a/ipsvd/udp_io.c +++ b/libbb/udp_io.c @@ -1,12 +1,13 @@ -/* Thus far used only by udpsvd.c */ +/* vi: set sw=4 ts=4: */ +/* + * Utility routines. + * + * Copyright (C) 2007 Denis Vlasenko + * + * Licensed under GPL version 2, see file LICENSE in this tarball for details. + */ -void socket_want_pktinfo(int fd); -ssize_t send_to_from(int fd, void *buf, size_t len, int flags, - const struct sockaddr *from, const struct sockaddr *to, - socklen_t tolen); -ssize_t recv_from_to(int fd, void *buf, size_t len, int flags, - struct sockaddr *from, struct sockaddr *to, - socklen_t sa_size); +#include "libbb.h" /* * This asks kernel to let us know dst addr/port of incoming packets diff --git a/libbb/xconnect.c b/libbb/xconnect.c index 3c1eec943..8466325c7 100644 --- a/libbb/xconnect.c +++ b/libbb/xconnect.c @@ -208,7 +208,7 @@ len_and_sockaddr* xdotted2sockaddr(const char *host, int port) return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR); } -static int xsocket_type(len_and_sockaddr **lsap, int sock_type) +int xsocket_type(len_and_sockaddr **lsap, int sock_type) { len_and_sockaddr *lsa; int fd; diff --git a/networking/Config.in b/networking/Config.in index f78056827..a40770540 100644 --- a/networking/Config.in +++ b/networking/Config.in @@ -467,7 +467,7 @@ config NC connections. config NC_SERVER - bool "Netcat server options (-lp)" + bool "Netcat server options (-l)" default n depends on NC help diff --git a/networking/nc.c b/networking/nc.c index bc7c701fe..e89eb7615 100644 --- a/networking/nc.c +++ b/networking/nc.c @@ -9,6 +9,10 @@ #include "busybox.h" +#if ENABLE_DESKTOP +#include "nc_bloaty.c" +#else + /* Lots of small differences in features * when compared to "standard" nc */ @@ -195,3 +199,4 @@ int nc_main(int argc, char **argv) } } } +#endif diff --git a/networking/nc_bloaty.c b/networking/nc_bloaty.c new file mode 100644 index 000000000..260d2057a --- /dev/null +++ b/networking/nc_bloaty.c @@ -0,0 +1,799 @@ +/* Based on netcat 1.10 RELEASE 960320 written by hobbit@avian.org. + * Released into public domain by the author. + * + * Copyright (C) 2007 Denis Vlasenko. + * + * Licensed under GPLv2, see file LICENSE in this tarball for details. + */ + +/* Author's comments from nc 1.10: + * ===================== + * Netcat is entirely my own creation, although plenty of other code was used as + * examples. It is freely given away to the Internet community in the hope that + * it will be useful, with no restrictions except giving credit where it is due. + * No GPLs, Berkeley copyrights or any of that nonsense. The author assumes NO + * responsibility for how anyone uses it. If netcat makes you rich somehow and + * you're feeling generous, mail me a check. If you are affiliated in any way + * with Microsoft Network, get a life. Always ski in control. Comments, + * questions, and patches to hobbit@avian.org. + * ... + * Netcat and the associated package is a product of Avian Research, and is freely + * available in full source form with no restrictions save an obligation to give + * credit where due. + * ... + * A damn useful little "backend" utility begun 950915 or thereabouts, + * as *Hobbit*'s first real stab at some sockets programming. Something that + * should have and indeed may have existed ten years ago, but never became a + * standard Unix utility. IMHO, "nc" could take its place right next to cat, + * cp, rm, mv, dd, ls, and all those other cryptic and Unix-like things. + * ===================== + * + * Much of author's comments are still retained in the code. + * + * Functionality removed (rationale): + * - miltiple-port ranges, randomized port scanning (use nmap) + * - telnet support (use telnet) + * - source routing + * - multiple DNS checks + * Functionalty which is different from nc 1.10: + * - Prog in '-e prog' can have prog's parameters and options. + * Because of this -e option must be last. + * - nc doesn't redirect stderr to the network socket for the -e prog. + */ + +/* done in nc.c: #include "busybox.h" */ + +#define SLEAZE_PORT 31337 /* for UDP-scan RTT trick, change if ya want */ +#define BIGSIZ 8192 /* big buffers */ + +struct globals { + int netfd; + int ofd; /* hexdump output fd */ +#if ENABLE_LFS +#define SENT_N_RECV_M "sent %llu, rcvd %llu\n" + unsigned long long wrote_out; /* total stdout bytes */ + unsigned long long wrote_net; /* total net bytes */ +#else +#define SENT_N_RECV_M "sent %u, rcvd %u" + unsigned wrote_out; /* total stdout bytes */ + unsigned wrote_net; /* total net bytes */ +#endif + /* ouraddr is never NULL and goes thru three states as we progress: + 1 - local address before bind (IP/port possibly zero) + 2 - local address after bind (port is nonzero) + 3 - local address after connect??/recv/accept (IP and port are nonzero) */ + struct len_and_sockaddr *ouraddr; + /* themaddr is NULL if no peer hostname[:port] specified on command line */ + struct len_and_sockaddr *themaddr; + /* remend is set after connect/recv/accept to the actual ip:port of peer */ + struct len_and_sockaddr remend; + + /* global cmd flags: */ + unsigned o_verbose; + unsigned o_wait; +#if ENABLE_NC_EXTRA + unsigned o_interval; +#endif + + jmp_buf jbuf; /* timer crud */ + unsigned char *stage; /* hexdump line buffer */ + + /* will malloc up the following globals: */ + fd_set ding1; /* for select loop */ + fd_set ding2; + char bigbuf_in[BIGSIZ]; /* data buffers */ + char bigbuf_net[BIGSIZ]; +}; + +#define G (*ptr_to_globals) + +#define netfd (G.netfd ) +#define ofd (G.ofd ) +#define wrote_out (G.wrote_out ) +#define wrote_net (G.wrote_net ) +#define ouraddr (G.ouraddr ) +#define themaddr (G.themaddr ) +#define remend (G.remend ) +#define jbuf (G.jbuf ) +#define stage (G.stage ) +#define ding1 (G.ding1 ) +#define ding2 (G.ding2 ) +#define bigbuf_in (G.bigbuf_in ) +#define bigbuf_net (G.bigbuf_net) +#define o_verbose (G.o_verbose ) +#define o_wait (G.o_wait ) +#if ENABLE_NC_EXTRA +#define o_interval (G.o_interval) +#else +#define o_interval 0 +#endif + +/* Must match getopt32 call! */ +enum { + OPT_h = (1 << 0), + OPT_n = (1 << 1), + OPT_p = (1 << 2), + OPT_s = (1 << 3), + OPT_u = (1 << 4), + OPT_v = (1 << 5), + OPT_w = (1 << 6), + OPT_l = (1 << 7) * ENABLE_NC_SERVER, + OPT_i = (1 << (7+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, + OPT_o = (1 << (8+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, + OPT_z = (1 << (9+ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA, +}; + +#define o_nflag (option_mask32 & OPT_n) +#define o_udpmode (option_mask32 & OPT_u) +#if ENABLE_NC_EXTRA +#define o_wfile (option_mask32 & OPT_o) +#define o_listen (option_mask32 & OPT_l) +#define o_zero (option_mask32 & OPT_z) +#else +#define o_wfile 0 +#define o_listen 0 +#define o_zero 0 +#endif + +/* Debug macro: squirt whatever message and sleep a bit so we can see it go + by. need to call like Debug((stuff)) [with no ; ] so macro args match! + Beware: writes to stdOUT... */ +#if 0 +#define Debug(x) printf x; printf("\n"); fflush(stdout); sleep(1); +#else +#define Debug(x) /* nil... */ +#endif + +#define holler_error(...) do { if (o_verbose) bb_error_msg(__VA_ARGS__); } while(0) +#define holler_perror(...) do { if (o_verbose) bb_perror_msg(__VA_ARGS__); } while(0) + +/* catch: no-brainer interrupt handler */ +static void catch(int sig) +{ + errno = 0; + if (o_verbose > 1) /* normally we don't care */ + fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out); + fprintf(stderr, "punt!\n"); +} + +/* timeout and other signal handling cruft */ +static void tmtravel(int sig) +{ + signal(SIGALRM, SIG_IGN); + alarm(0); + longjmp(jbuf, 1); +} + +/* arm: set the timer. */ +static void arm(unsigned secs) +{ + signal(SIGALRM, tmtravel); + alarm(secs); +} + +/* unarm */ +static void unarm(void) +{ + signal(SIGALRM, SIG_IGN); + alarm(0); +} + +/* findline: + find the next newline in a buffer; return inclusive size of that "line", + or the entire buffer size, so the caller knows how much to then write(). + Not distinguishing \n vs \r\n for the nonce; it just works as is... */ +static unsigned findline(char *buf, unsigned siz) +{ + char * p; + int x; + if (!buf) /* various sanity checks... */ + return 0; + if (siz > BIGSIZ) + return 0; + x = siz; + for (p = buf; x > 0; x--) { + if (*p == '\n') { + x = (int) (p - buf); + x++; /* 'sokay if it points just past the end! */ +Debug(("findline returning %d", x)) + return x; + } + p++; + } /* for */ +Debug(("findline returning whole thing: %d", siz)) + return siz; +} /* findline */ + +/* doexec: + fiddle all the file descriptors around, and hand off to another prog. Sort + of like a one-off "poor man's inetd". This is the only section of code + that would be security-critical, which is why it's ifdefed out by default. + Use at your own hairy risk; if you leave shells lying around behind open + listening ports you deserve to lose!! */ +static int doexec(char **proggie) ATTRIBUTE_NORETURN; +static int doexec(char **proggie) +{ + xmove_fd(netfd, 0); + dup2(0, 1); + /* dup2(0, 2); - do we *really* want this? NO! + * exec'ed prog can do it yourself, if needed */ + execvp(proggie[0], proggie); + bb_perror_msg_and_die("exec"); +} + +/* connect_w_timeout: + return an fd for one of + an open outbound TCP connection, a UDP stub-socket thingie, or + an unconnected TCP or UDP socket to listen on. + Examines various global o_blah flags to figure out what to do. + lad can be NULL, then socket is not bound to any local ip[:port] */ +static int connect_w_timeout(int fd) +{ + int rr; + + /* wrap connect inside a timer, and hit it */ + arm(o_wait); + if (setjmp(jbuf) == 0) { + rr = connect(fd, &themaddr->sa, themaddr->len); + } else { /* setjmp: connect failed... */ + rr = -1; + errno = ETIMEDOUT; /* fake it */ + } + unarm(); + return rr; +} + +/* dolisten: + listens for + incoming and returns an open connection *from* someplace. If we were + given host/port args, any connections from elsewhere are rejected. This + in conjunction with local-address binding should limit things nicely... */ +static void dolisten(void) +{ + int rr; + const char *errmsg = errmsg; /* gcc */ + + if (!o_udpmode) + xlisten(netfd, 1); /* TCP: gotta listen() before we can get */ + + /* Various things that follow temporarily trash bigbuf_net, which might contain + a copy of any recvfrom()ed packet, but we'll read() another copy later. */ + + /* I can't believe I have to do all this to get my own goddamn bound address + and port number. It should just get filled in during bind() or something. + All this is only useful if we didn't say -p for listening, since if we + said -p we *know* what port we're listening on. At any rate we won't bother + with it all unless we wanted to see it, although listening quietly on a + random unknown port is probably not very useful without "netstat". */ + if (o_verbose) { + char *addr; + rr = getsockname(netfd, &ouraddr->sa, &ouraddr->len); + if (rr < 0) + bb_perror_msg_and_die("getsockname after bind"); + addr = xmalloc_sockaddr2dotted(&ouraddr->sa, ouraddr->len); + fprintf(stderr, "listening on [%s] ...\n", addr); + free(addr); + } + + if (o_udpmode) { + /* UDP is a speeeeecial case -- we have to do I/O *and* get the calling + party's particulars all at once, listen() and accept() don't apply. + At least in the BSD universe, however, recvfrom/PEEK is enough to tell + us something came in, and we can set things up so straight read/write + actually does work after all. Yow. YMMV on strange platforms! */ + + /* I'm not completely clear on how this works -- BSD seems to make UDP + just magically work in a connect()ed context, but we'll undoubtedly run + into systems this deal doesn't work on. For now, we apparently have to + issue a connect() on our just-tickled socket so we can write() back. + Again, why the fuck doesn't it just get filled in and taken care of?! + This hack is anything but optimal. Basically, if you want your listener + to also be able to send data back, you need this connect() line, which + also has the side effect that now anything from a different source or even a + different port on the other end won't show up and will cause ICMP errors. + I guess that's what they meant by "connect". + Let's try to remember what the "U" is *really* for, eh? */ + + /* If peer address is specified, connect to it */ + if (themaddr) { + remend = *themaddr; + xconnect(netfd, &themaddr->sa, themaddr->len); + rr = 0; + } else { /* peek first packet and remember peer addr */ + arm(o_wait); /* might as well timeout this, too */ + if (setjmp(jbuf) == 0) { /* do timeout for initial connect */ + /* (*ouraddr) is prefilled with "default" address */ + /* and here we block... */ + rr = recv_from_to(netfd, NULL, 0, MSG_PEEK, /*was bigbuf_net, BIGSIZ*/ + &remend.sa, &ouraddr->sa, ouraddr->len); + if (rr < 0) + bb_perror_msg_and_die("recvfrom"); + } else + bb_error_msg_and_die("timeout"); + unarm(); + rr = connect(netfd, &remend.sa, ouraddr->len); + errmsg = "connect"; + } + } else { + /* TCP */ + arm(o_wait); /* wrap this in a timer, too; 0 = forever */ + if (setjmp(jbuf) == 0) { + remend.len = LSA_SIZEOF_SA; + rr = accept(netfd, &remend.sa, &remend.len); + } else + bb_error_msg_and_die("timeout"); + unarm(); + errmsg = "accept"; + if (rr >= 0) { + close(netfd); /* dump the old socket */ + netfd = rr; /* here's our new one */ + /* find out what address the connection was *to* on our end, in case we're + doing a listen-on-any on a multihomed machine. This allows one to + offer different services via different alias addresses, such as the + "virtual web site" hack. */ + rr = getsockname(netfd, &ouraddr->sa, &ouraddr->len); + errmsg = "getsockname after accept"; + } + } + if (rr < 0) + bb_perror_msg_and_die(errmsg); + +#if ENABLE_NC_EXTRA && defined(IP_OPTIONS) + /* If we can, look for any IP options. Useful for testing the receiving end of + such things, and is a good exercise in dealing with it. We do this before + the connect message, to ensure that the connect msg is uniformly the LAST + thing to emerge after all the intervening crud. Doesn't work for UDP on + any machines I've tested, but feel free to surprise me. */ + if (o_verbose) { + char optbuf[40]; + int x = sizeof(optbuf); + rr = getsockopt(netfd, IPPROTO_IP, IP_OPTIONS, optbuf, &x); + if (rr < 0) + bb_perror_msg("getsockopt failed"); + else if (x) { /* we've got options, lessee em... */ + bin2hex(bigbuf_net, optbuf, x); + bigbuf_net[2*x] = '\0'; + fprintf(stderr, "IP options: %s\n", bigbuf_net); + } + } +#endif + + /* now check out who it is. We don't care about mismatched DNS names here, + but any ADDR and PORT we specified had better fucking well match the caller. + Converting from addr to inet_ntoa and back again is a bit of a kludge, but + gethostpoop wants a string and there's much gnarlier code out there already, + so I don't feel bad. + The *real* question is why BFD sockets wasn't designed to allow listens for + connections *from* specific hosts/ports, instead of requiring the caller to + accept the connection and then reject undesireable ones by closing. + In other words, we need a TCP MSG_PEEK. */ + /* bbox: removed most of it */ + if (o_verbose) { + char *lcladdr = xmalloc_sockaddr2dotted(&ouraddr->sa, ouraddr->len); + char *remaddr = xmalloc_sockaddr2dotted(&remend.sa, remend.len); + char *remhostname = o_nflag ? remaddr : xmalloc_sockaddr2host(&remend.sa, remend.len); + fprintf(stderr, "connect to [%s] from %s [%s]\n", + lcladdr, remhostname, remaddr); + free(lcladdr); + free(remaddr); + if (!o_nflag) + free(remhostname); + } +} + +/* udptest: + fire a couple of packets at a UDP target port, just to see if it's really + there. On BSD kernels, ICMP host/port-unreachable errors get delivered to + our socket as ECONNREFUSED write errors. On SV kernels, we lose; we'll have + to collect and analyze raw ICMP ourselves a la satan's probe_udp_ports + backend. Guess where one could swipe the appropriate code from... + + Use the time delay between writes if given, otherwise use the "tcp ping" + trick for getting the RTT. [I got that idea from pluvius, and warped it.] + Return either the original fd, or clean up and return -1. */ +static int udptest(void) +{ + int rr; + + rr = write(netfd, bigbuf_in, 1); + if (rr != 1) + bb_perror_msg("udptest first write"); + + if (o_wait) + sleep(o_wait); + else { + /* use the tcp-ping trick: try connecting to a normally refused port, which + causes us to block for the time that SYN gets there and RST gets back. + Not completely reliable, but it *does* mostly work. */ + /* Set a temporary connect timeout, so packet filtration doesnt cause + us to hang forever, and hit it */ + o_wait = 5; /* enough that we'll notice?? */ + rr = xsocket(ouraddr->sa.sa_family, SOCK_STREAM, 0); + set_nport(themaddr, htons(SLEAZE_PORT)); + connect_w_timeout(rr); +//need to restore port? + close(rr); + o_wait = 0; /* reset it */ + } + + rr = write(netfd, bigbuf_in, 1); + return (rr != 1); /* if rr == 1, return 0 (success) */ +} + +/* oprint: + Hexdump bytes shoveled either way to a running logfile, in the format: + D offset - - - - --- 16 bytes --- - - - - # .... ascii ..... + where "which" sets the direction indicator, D: + 0 -- sent to network, or ">" + 1 -- rcvd and printed to stdout, or "<" + and "buf" and "n" are data-block and length. If the current block generates + a partial line, so be it; we *want* that lockstep indication of who sent + what when. Adapted from dgaudet's original example -- but must be ripping + *fast*, since we don't want to be too disk-bound... */ +static void oprint(int which, char *buf, int n) +{ + int bc; /* in buffer count */ + int obc; /* current "global" offset */ + int soc; /* stage write count */ + unsigned char *p; /* main buf ptr; m.b. unsigned here */ + unsigned char *op; /* out hexdump ptr */ + unsigned char *a; /* out asc-dump ptr */ + int x; + + if (n == 0) + return; + + op = stage; + if (which) { + *op = '<'; + obc = wrote_out; /* use the globals! */ + } else { + *op = '>'; + obc = wrote_net; + } + op++; /* preload "direction" */ + *op = ' '; + p = (unsigned char *) buf; + bc = n; + stage[59] = '#'; /* preload separator */ + stage[60] = ' '; + + while (bc) { /* for chunk-o-data ... */ + x = 16; + soc = 78; /* len of whole formatted line */ + if (bc < x) { + soc = soc - 16 + bc; /* fiddle for however much is left */ + x = (bc * 3) + 11; /* 2 digits + space per, after D & offset */ + op = &stage[x]; + x = 16 - bc; + while (x) { + *op++ = ' '; /* preload filler spaces */ + *op++ = ' '; + *op++ = ' '; + x--; + } + x = bc; /* re-fix current linecount */ + } /* if bc < x */ + + bc -= x; /* fix wrt current line size */ + sprintf(&stage[2], "%8.8x ", obc); /* xxx: still slow? */ + obc += x; /* fix current offset */ + op = &stage[11]; /* where hex starts */ + a = &stage[61]; /* where ascii starts */ + + while (x) { /* for line of dump, however long ... */ + *op++ = 0x20 | bb_hexdigits_upcase[*p >> 4]; + *op++ = 0x20 | bb_hexdigits_upcase[*p & 0x0f]; + *op++ = ' '; + if ((*p > 31) && (*p < 127)) + *a = *p; /* printing */ + else + *a = '.'; /* nonprinting, loose def */ + a++; + p++; + x--; + } /* while x */ + *a = '\n'; /* finish the line */ + xwrite(ofd, stage, soc); + } /* while bc */ +} + +/* readwrite: + handle stdin/stdout/network I/O. Bwahaha!! -- the select loop from hell. + In this instance, return what might become our exit status. */ +static int readwrite(void) +{ + int rr; + char *zp = zp; /* gcc */ /* stdin buf ptr */ + char *np = np; /* net-in buf ptr */ + unsigned rzleft; + unsigned rnleft; + unsigned netretry; /* net-read retry counter */ + unsigned wretry; /* net-write sanity counter */ + unsigned wfirst; /* one-shot flag to skip first net read */ + + /* if you don't have all this FD_* macro hair in sys/types.h, you'll have to + either find it or do your own bit-bashing: *ding1 |= (1 << fd), etc... */ + FD_SET(netfd, &ding1); /* global: the net is open */ + netretry = 2; + wfirst = 0; + rzleft = rnleft = 0; + if (o_interval) + sleep(o_interval); /* pause *before* sending stuff, too */ + + errno = 0; /* clear from sleep, close, whatever */ + /* and now the big ol' select shoveling loop ... */ + while (FD_ISSET(netfd, &ding1)) { /* i.e. till the *net* closes! */ + wretry = 8200; /* more than we'll ever hafta write */ + if (wfirst) { /* any saved stdin buffer? */ + wfirst = 0; /* clear flag for the duration */ + goto shovel; /* and go handle it first */ + } + ding2 = ding1; /* FD_COPY ain't portable... */ + /* some systems, notably linux, crap into their select timers on return, so + we create a expendable copy and give *that* to select. */ + if (o_wait) { + struct timeval tmp_timer; + tmp_timer.tv_sec = o_wait; + tmp_timer.tv_usec = 0; + rr = select(16, &ding2, NULL, NULL, &tmp_timer); + } else + rr = select(16, &ding2, NULL, NULL, NULL); + if (rr < 0 && errno != EINTR) { /* might have gotten ^Zed, etc */ + holler_perror("select"); + close(netfd); + return 1; + } + /* if we have a timeout AND stdin is closed AND we haven't heard anything + from the net during that time, assume it's dead and close it too. */ + if (rr == 0) { + if (!FD_ISSET(0, &ding1)) + netretry--; /* we actually try a coupla times. */ + if (!netretry) { + if (o_verbose > 1) /* normally we don't care */ + fprintf(stderr, "net timeout\n"); + close(netfd); + return 0; /* not an error! */ + } + } /* select timeout */ + /* xxx: should we check the exception fds too? The read fds seem to give + us the right info, and none of the examples I found bothered. */ + + /* Ding!! Something arrived, go check all the incoming hoppers, net first */ + if (FD_ISSET(netfd, &ding2)) { /* net: ding! */ + rr = read(netfd, bigbuf_net, BIGSIZ); + if (rr <= 0) { + FD_CLR(netfd, &ding1); /* net closed, we'll finish up... */ + rzleft = 0; /* can't write anymore: broken pipe */ + } else { + rnleft = rr; + np = bigbuf_net; + } +Debug(("got %d from the net, errno %d", rr, errno)) + } /* net:ding */ + + /* if we're in "slowly" mode there's probably still stuff in the stdin + buffer, so don't read unless we really need MORE INPUT! MORE INPUT! */ + if (rzleft) + goto shovel; + + /* okay, suck more stdin */ + if (FD_ISSET(0, &ding2)) { /* stdin: ding! */ + rr = read(0, bigbuf_in, BIGSIZ); + /* Considered making reads here smaller for UDP mode, but 8192-byte + mobygrams are kinda fun and exercise the reassembler. */ + if (rr <= 0) { /* at end, or fukt, or ... */ + FD_CLR(0, &ding1); /* disable and close stdin */ + close(0); + } else { + rzleft = rr; + zp = bigbuf_in; + } + } /* stdin:ding */ + shovel: + /* now that we've dingdonged all our thingdings, send off the results. + Geez, why does this look an awful lot like the big loop in "rsh"? ... + not sure if the order of this matters, but write net -> stdout first. */ + + /* sanity check. Works because they're both unsigned... */ + if ((rzleft > 8200) || (rnleft > 8200)) { + holler_error("bogus buffers: %u, %u", rzleft, rnleft); + rzleft = rnleft = 0; + } + /* net write retries sometimes happen on UDP connections */ + if (!wretry) { /* is something hung? */ + holler_error("too many output retries"); + return 1; + } + if (rnleft) { + rr = write(1, np, rnleft); + if (rr > 0) { + if (o_wfile) + oprint(1, np, rr); /* log the stdout */ + np += rr; /* fix up ptrs and whatnot */ + rnleft -= rr; /* will get sanity-checked above */ + wrote_out += rr; /* global count */ + } +Debug(("wrote %d to stdout, errno %d", rr, errno)) + } /* rnleft */ + if (rzleft) { + if (o_interval) /* in "slowly" mode ?? */ + rr = findline(zp, rzleft); + else + rr = rzleft; + rr = write(netfd, zp, rr); /* one line, or the whole buffer */ + if (rr > 0) { + if (o_wfile) + oprint(0, zp, rr); /* log what got sent */ + zp += rr; + rzleft -= rr; + wrote_net += rr; /* global count */ + } +Debug(("wrote %d to net, errno %d", rr, errno)) + } /* rzleft */ + if (o_interval) { /* cycle between slow lines, or ... */ + sleep(o_interval); + errno = 0; /* clear from sleep */ + continue; /* ...with hairy select loop... */ + } + if ((rzleft) || (rnleft)) { /* shovel that shit till they ain't */ + wretry--; /* none left, and get another load */ + goto shovel; + } + } /* while ding1:netfd is open */ + + /* XXX: maybe want a more graceful shutdown() here, or screw around with + linger times?? I suspect that I don't need to since I'm always doing + blocking reads and writes and my own manual "last ditch" efforts to read + the net again after a timeout. I haven't seen any screwups yet, but it's + not like my test network is particularly busy... */ + close(netfd); + return 0; +} /* readwrite */ + +/* main: now we pull it all together... */ +int nc_main(int argc, char **argv); +int nc_main(int argc, char **argv) +{ + char *str_p, *str_s, *str_w; + USE_NC_EXTRA(char *str_i;) + char *themdotted = themdotted; /* gcc */ + char **proggie; + int x; + unsigned o_lport = 0; + + /* I was in this barbershop quartet in Skokie IL ... */ + /* round up the usual suspects, i.e. malloc up all the stuff we need */ + PTR_TO_GLOBALS = xzalloc(sizeof(G)); + + /* catch a signal or two for cleanup */ + signal(SIGINT, catch); + signal(SIGQUIT, catch); + signal(SIGTERM, catch); + /* and suppress others... */ +#ifdef SIGURG + signal(SIGURG, SIG_IGN); +#endif + signal(SIGPIPE, SIG_IGN); /* important! */ + + proggie = argv; + while (*++proggie) { + if (strcmp(*proggie, "-e") == 0) { + *proggie = NULL; + argc = proggie - argv; + proggie++; + goto e_found; + } + } + proggie = NULL; + e_found: + + // -g -G -t -r deleted, unimplemented -a deleted too + opt_complementary = "?2:vv"; /* max 2 params, -v is a counter */ + getopt32(argc, argv, "hnp:s:uvw:" USE_NC_SERVER("l") + USE_NC_EXTRA("i:o:z"), + &str_p, &str_s, &str_w + USE_NC_EXTRA(, &str_i, &stage, &o_verbose)); + argv += optind; +#if ENABLE_NC_EXTRA + if (option_mask32 & OPT_i) /* line-interval time */ + o_interval = xatou_range(str_i, 1, 0xffff); +#endif + //if (option_mask32 & OPT_l) /* listen mode */ + //if (option_mask32 & OPT_n) /* numeric-only, no DNS lookups */ + //if (option_mask32 & OPT_o) /* hexdump log */ + if (option_mask32 & OPT_p) { /* local source port */ + o_lport = bb_lookup_port(str_p, o_udpmode ? "udp" : "tcp", 0); + if (!o_lport) + bb_error_msg_and_die("bad local port '%s'", str_p); + } + //if (option_mask32 & OPT_r) /* randomize various things */ + //if (option_mask32 & OPT_u) /* use UDP */ + //if (option_mask32 & OPT_v) /* verbose */ + if (option_mask32 & OPT_w) { /* wait time */ + o_wait = xatoi_u(str_w); + } + //if (option_mask32 & OPT_z) /* little or no data xfer */ + + bb_sanitize_stdio(); + + /* create & bind network socket */ + if (option_mask32 & OPT_s) { /* local address */ + /* if o_port is still 0, then we will use random port */ + ouraddr = xhost2sockaddr(str_s, o_lport); + netfd = xsocket(ouraddr->sa.sa_family, o_udpmode ? SOCK_DGRAM : SOCK_STREAM, 0); //// 0? + } else { + netfd = xsocket_type(&ouraddr, o_udpmode ? SOCK_DGRAM : SOCK_STREAM); + if (o_lport) + set_nport(ouraddr, htons(o_lport)); + } + setsockopt_reuseaddr(netfd); + if (o_udpmode) + socket_want_pktinfo(netfd); + xbind(netfd, &ouraddr->sa, ouraddr->len); +#if 0 + setsockopt(netfd, SOL_SOCKET, SO_RCVBUF, &o_rcvbuf, sizeof o_rcvbuf); + setsockopt(netfd, SOL_SOCKET, SO_SNDBUF, &o_sndbuf, sizeof o_sndbuf); +#endif + + if (o_udpmode) { /* apparently UDP can listen ON */ + if (!o_lport) /* "port 0", but that's not useful */ + bb_error_msg_and_die("UDP listen needs -p arg"); + } + + FD_SET(0, &ding1); /* stdin *is* initially open */ + if (proggie) { + close(0); /* won't need stdin */ + option_mask32 &= ~OPT_o; /* -o with -e is meaningless! */ + ofd = 0; + } + if (o_wfile) { + ofd = xopen(stage, O_WRONLY|O_CREAT|O_TRUNC); + stage = xzalloc(100); + } + + if (argv[0]) { + themaddr = xhost2sockaddr(argv[0], + argv[1] + ? bb_lookup_port(argv[1], o_udpmode ? "udp" : "tcp", 0) + : 0); +///what if sa_family won't match?? + } + + if (o_listen) { + dolisten(); + /* dolisten does its own connect reporting */ + if (proggie) /* -e given? */ + doexec(proggie); + x = readwrite(); /* it even works with UDP! */ + } else { + /* Outbound connects. Now we're more picky about args... */ + if (!themaddr) + bb_error_msg_and_die("no destination"); + + remend = *themaddr; + if (o_verbose) + themdotted = xmalloc_sockaddr2dotted(&themaddr->sa, themaddr->len); + + x = connect_w_timeout(netfd); + if (o_zero && x == 0 && o_udpmode) /* if UDP scanning... */ + x = udptest(); + if (x == 0) { /* Yow, are we OPEN YET?! */ + if (o_verbose) + fprintf(stderr, "%s [%s] open\n", argv[0], themdotted); + if (proggie) /* exec is valid for outbound, too */ + doexec(proggie); + if (!o_zero) + x = readwrite(); + } else { /* connect or udptest wasn't successful */ + x = 1; /* exit status */ + /* if we're scanning at a "one -v" verbosity level, don't print refusals. + Give it another -v if you want to see everything. */ + if (o_verbose > 1 || (o_verbose && errno != ECONNREFUSED)) + bb_perror_msg("%s [%s]", argv[0], themdotted); + } + } + if (o_verbose > 1) /* normally we don't care */ + fprintf(stderr, SENT_N_RECV_M, wrote_net, wrote_out); + return x; +} |