From ffeeb7a96c74f1f001495c2311526681e2271a77 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 28 Jul 2013 22:23:12 +0200 Subject: nc: exit when both stdin and network are closed. function old new delta nc_main 1051 1042 -9 readwrite 943 887 -56 Signed-off-by: Denys Vlasenko --- networking/nc_bloaty.c | 50 +++++++++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 19 deletions(-) (limited to 'networking/nc_bloaty.c') diff --git a/networking/nc_bloaty.c b/networking/nc_bloaty.c index 00ba6f114..f01e862ae 100644 --- a/networking/nc_bloaty.c +++ b/networking/nc_bloaty.c @@ -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 -- cgit v1.2.3