hexedit: position in correct column on "goto" command
[oweals/busybox.git] / networking / nc_bloaty.c
index 00ba6f114657cf7660132fb670b4b53637e61aab..64098648aae6a86abcddc970aae788bba8c6c389 100644 (file)
  * - TCP connects from wrong ip/ports (if peer ip:port is specified
  *   on the command line, but accept() says that it came from different addr)
  *   are closed, but we don't exit - we continue to listen/accept.
+ * Since bbox 1.22:
+ * - nc exits when _both_ stdin and network are closed.
+ *   This makes these two commands:
+ *    echo "Yes" | nc 127.0.0.1 1234
+ *    echo "no" | nc -lp 1234
+ *   exchange their data _and exit_ instead of being stuck.
  */
 
 /* done in nc.c: #include "libbb.h" */
@@ -134,8 +140,6 @@ struct globals {
 
        jmp_buf jbuf;                /* timer crud */
 
-       fd_set ding1;                /* for select loop */
-       fd_set ding2;
        char bigbuf_in[BIGSIZ];      /* data buffers */
        char bigbuf_net[BIGSIZ];
 };
@@ -147,8 +151,6 @@ struct globals {
 #define themaddr   (G.themaddr  )
 #define remend     (G.remend    )
 #define jbuf       (G.jbuf      )
-#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 )
@@ -173,9 +175,9 @@ enum {
        OPT_w = (1 << 5),
        OPT_l = (1 << 6) * ENABLE_NC_SERVER,
        OPT_k = (1 << 7) * ENABLE_NC_SERVER,
-       OPT_i = (1 << (7+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA,
-       OPT_o = (1 << (8+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA,
-       OPT_z = (1 << (9+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA,
+       OPT_i = (1 << (6+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA,
+       OPT_o = (1 << (7+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA,
+       OPT_z = (1 << (8+2*ENABLE_NC_SERVER)) * ENABLE_NC_EXTRA,
 };
 
 #define o_nflag   (option_mask32 & OPT_n)
@@ -457,7 +459,7 @@ create new one, and bind() it. TODO */
         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.
+        accept the connection and then reject undesirable ones by closing.
         In other words, we need a TCP MSG_PEEK. */
        /* bbox: removed most of it */
                lcladdr = xmalloc_sockaddr2dotted(&ouraddr->u.sa);
@@ -500,7 +502,7 @@ static int udptest(void)
        /* 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
+       /* Set a temporary connect timeout, so packet filtration doesn't cause
         us to hang forever, and hit it */
                o_wait = 5;                     /* enough that we'll notice?? */
                rr = xsocket(ouraddr->u.sa.sa_family, SOCK_STREAM, 0);
@@ -580,76 +582,72 @@ void oprint(int direction, unsigned char *p, unsigned bc);
 #endif
 
 /* readwrite:
- handle stdin/stdout/network I/O.  Bwahaha!! -- the select loop from hell.
+ handle stdin/stdout/network I/O.  Bwahaha!! -- the i/o 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 */
+       unsigned fds_open;
+
+       struct pollfd pfds[2];
+       pfds[0].fd = STDIN_FILENO;
+       pfds[0].events = POLLIN;
+       pfds[1].fd = netfd;
+       pfds[1].events = POLLIN;
 
-       /* 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 */
+       fds_open = 2;
        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.  */
+       /* and now the big ol' shoveling loop ... */
+       /* nc 1.10 has "while (FD_ISSET(netfd)" here */
+       while (fds_open) {
+               int rr;
+               int poll_tmout_ms;
+               unsigned wretry = 8200;               /* net-write sanity counter */
+
+               poll_tmout_ms = -1;
                if (o_wait) {
-                       struct timeval tmp_timer;
-                       tmp_timer.tv_sec = o_wait;
-                       tmp_timer.tv_usec = 0;
-               /* highest possible fd is netfd (3) */
-                       rr = select(netfd+1, &ding2, NULL, NULL, &tmp_timer);
-               } else
-                       rr = select(netfd+1, &ding2, NULL, NULL, NULL);
+                       poll_tmout_ms = INT_MAX;
+                       if (o_wait < INT_MAX / 1000)
+                               poll_tmout_ms = o_wait * 1000;
+               }
+               rr = poll(pfds, 2, poll_tmout_ms);
                if (rr < 0 && errno != EINTR) {                /* might have gotten ^Zed, etc */
-                       holler_perror("select");
+                       holler_perror("poll");
                        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(STDIN_FILENO, &ding1))
+                       if (!pfds[0].revents) {
                                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! */
+                               if (!netretry) {
+                                       if (o_verbose > 1)         /* normally we don't care */
+                                               fprintf(stderr, "net timeout\n");
+                                       /*close(netfd); - redundant, exit will do it */
+                                       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. */
+               } /* timeout */
 
        /* Ding!!  Something arrived, go check all the incoming hoppers, net first */
-               if (FD_ISSET(netfd, &ding2)) {                /* net: ding! */
+               if (pfds[1].revents) {                /* net: ding! */
                        rr = read(netfd, bigbuf_net, BIGSIZ);
                        if (rr <= 0) {
                                if (rr < 0 && o_verbose > 1) {
                                        /* nc 1.10 doesn't do this */
                                        bb_perror_msg("net read");
                                }
-                               FD_CLR(netfd, &ding1);                /* net closed, we'll finish up... */
+                               pfds[1].fd = -1;                   /* don't poll for netfd anymore */
+                               fds_open--;
                                rzleft = 0;                        /* can't write anymore: broken pipe */
                        } else {
                                rnleft = rr;
@@ -664,16 +662,17 @@ Debug("got %d from the net, errno %d", rr, errno);
                        goto shovel;
 
        /* okay, suck more stdin */
-               if (FD_ISSET(STDIN_FILENO, &ding2)) {                /* stdin: ding! */
+               if (pfds[0].revents) {                /* stdin: ding! */
                        rr = read(STDIN_FILENO, 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(STDIN_FILENO, &ding1);                /* disable and close stdin */
-                               close(STDIN_FILENO);
-// Does it make sense to shutdown(net_fd, SHUT_WR)
-// to let other side know that we won't write anything anymore?
-// (and what about keeping compat if we do that?)
+                               pfds[0].fd = -1;              /* disable stdin */
+                               /*close(STDIN_FILENO); - not really necessary */
+                               /* Let peer know we have no more data */
+                               /* nc 1.10 doesn't do this: */
+                               shutdown(netfd, SHUT_WR);
+                               fds_open--;
                        } else {
                                rzleft = rr;
                                zp = bigbuf_in;
@@ -684,24 +683,14 @@ Debug("got %d from the net, errno %d", rr, errno);
         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(STDOUT_FILENO, np, rnleft);
                        if (rr > 0) {
                                if (o_ofile) /* log the stdout */
                                        oprint('<', (unsigned char *)np, rr);
-                               np += rr;                        /* fix up ptrs and whatnot */
-                               rnleft -= rr;                        /* will get sanity-checked above */
-                               wrote_out += rr;                /* global count */
+                               np += rr;
+                               rnleft -= rr;
+                               wrote_out += rr; /* global count */
                        }
 Debug("wrote %d to stdout, errno %d", rr, errno);
                } /* rnleft */
@@ -716,20 +705,24 @@ Debug("wrote %d to stdout, errno %d", rr, errno);
                                        oprint('>', (unsigned char *)zp, rr);
                                zp += rr;
                                rzleft -= rr;
-                               wrote_net += rr;                /* global count */
+                               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... */
+                       continue;                        /* ...with hairy loop... */
                }
-               if ((rzleft) || (rnleft)) {                /* shovel that shit till they ain't */
+               if (rzleft || rnleft) {                  /* shovel that shit till they ain't */
                        wretry--;                        /* none left, and get another load */
+       /* net write retries sometimes happen on UDP connections */
+                       if (!wretry) {                   /* is something hung? */
+                               holler_error("too many output retries");
+                               return 1;
+                       }
                        goto shovel;
                }
-       } /* while ding1:netfd is open */
+       } /* while (fds_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
@@ -794,11 +787,15 @@ int nc_main(int argc UNUSED_PARAM, char **argv)
  e_found:
 
        // -g -G -t -r deleted, unimplemented -a deleted too
-       opt_complementary = "?2:vv:ll:w+"; /* max 2 params; -v and -l are counters; -w N */
-       getopt32(argv, "np:s:uvw:" IF_NC_SERVER("lk")
-                       IF_NC_EXTRA("i:o:z"),
-                       &str_p, &str_s, &o_wait
-                       IF_NC_EXTRA(, &str_i, &str_o), &o_verbose IF_NC_SERVER(, &cnt_l));
+       getopt32(argv, "^"
+               "np:s:uvw:+"/* -w N */ IF_NC_SERVER("lk")
+               IF_NC_EXTRA("i:o:z")
+                       "\0"
+                       "?2:vv:ll", /* max 2 params; -v and -l are counters */
+               &str_p, &str_s, &o_wait
+               IF_NC_EXTRA(, &str_i, &str_o)
+                       , &o_verbose IF_NC_SERVER(, &cnt_l)
+       );
        argv += optind;
 #if ENABLE_NC_EXTRA
        if (option_mask32 & OPT_i) /* line-interval time */
@@ -863,8 +860,8 @@ int nc_main(int argc UNUSED_PARAM, char **argv)
                xbind(netfd, &ouraddr->u.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);
+       setsockopt_SOL_SOCKET_int(netfd, SO_RCVBUF, o_rcvbuf);
+       setsockopt_SOL_SOCKET_int(netfd, SO_SNDBUF, o_sndbuf);
 #endif
 
 #ifdef BLOAT
@@ -876,9 +873,8 @@ int nc_main(int argc UNUSED_PARAM, char **argv)
        }
 #endif
 
-       FD_SET(STDIN_FILENO, &ding1);                        /* stdin *is* initially open */
        if (proggie) {
-               close(0); /* won't need stdin */
+               close(STDIN_FILENO); /* won't need stdin */
                option_mask32 &= ~OPT_o; /* -o with -e is meaningless! */
        }
 #if ENABLE_NC_EXTRA