ffeeb7a96
Denys Vlasenko
2013-07-28
Subject
nc: exit when both stdin and network are closed.
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networking/nc_bloaty.c+31 -19
| @@ -48,6 +48,12 @@ | |
| * - 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 ) | |
| @@ -592,10 +594,17 @@ static int readwrite(void) | |
| 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; |
| /* 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 */ |
| + | fd_set ding1; /* for select loop */ |
| + | fd_set ding2; |
| + | FD_ZERO(&ding1); |
| + | FD_SET(netfd, &ding1); |
| + | FD_SET(STDIN_FILENO, &ding1); |
| + | fds_open = 2; |
| + | |
| netretry = 2; | |
| wfirst = 0; | |
| rzleft = rnleft = 0; | |
| @@ -604,7 +613,8 @@ static int readwrite(void) | |
| 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! */ |
| + | /* nc 1.10 has "while (FD_ISSET(netfd)" here */ |
| + | while (fds_open) { |
| wretry = 8200; /* more than we'll ever hafta write */ | |
| if (wfirst) { /* any saved stdin buffer? */ | |
| wfirst = 0; /* clear flag for the duration */ | |
| @@ -629,13 +639,14 @@ static int readwrite(void) | |
| /* 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 (!FD_ISSET(STDIN_FILENO, &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! */ |
| + | 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 | |
| @@ -649,7 +660,8 @@ static int readwrite(void) | |
| /* nc 1.10 doesn't do this */ | |
| bb_perror_msg("net read"); | |
| } | |
| - | FD_CLR(netfd, &ding1); /* net closed, we'll finish up... */ |
| + | FD_CLR(netfd, &ding1); /* net closed */ |
| + | fds_open--; |
| rzleft = 0; /* can't write anymore: broken pipe */ | |
| } else { | |
| rnleft = rr; | |
| @@ -671,9 +683,10 @@ Debug("got %d from the net, errno %d", rr, errno); | |
| 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?) |
| + | /* 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; | |
| @@ -725,7 +738,7 @@ Debug("wrote %d to net, errno %d", rr, errno); | |
| errno = 0; /* clear from sleep */ | |
| continue; /* ...with hairy select 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 */ | |
| goto shovel; | |
| } | |
| @@ -876,9 +889,8 @@ 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 | |