63416cc57
Tomoya Adachi
2009-08-03
Subject
nc: fix nc -ll; report vfork errors; make select loop faster
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networking/nc.c+23 -20
| @@ -135,29 +135,27 @@ int nc_main(int argc, char **argv) | |
| /* -e given? */ | |
| if (execparam) { | |
| - | signal(SIGCHLD, SIG_IGN); |
| - | // With more than one -l, repeatedly act as server. |
| - | if (do_listen > 1 && vfork()) { |
| - | /* parent */ |
| - | // This is a bit weird as cleanup goes, since we wind up with no |
| - | // stdin/stdout/stderr. But it's small and shouldn't hurt anything. |
| - | // We check for cfd == 0 above. |
| - | logmode = LOGMODE_NONE; |
| - | close(0); |
| - | close(1); |
| - | close(2); |
| + | pid_t pid; |
| + | /* With more than one -l, repeatedly act as server */ |
| + | if (do_listen > 1 && (pid = vfork()) != 0) { |
| + | /* parent or error */ |
| + | if (pid < 0) |
| + | bb_perror_msg_and_die("vfork"); |
| + | /* prevent zombies */ |
| + | signal(SIGCHLD, SIG_IGN); |
| + | close(cfd); |
| goto accept_again; | |
| } | |
| - | /* child (or main thread if no multiple -l) */ |
| + | /* child, or main thread if only one -l */ |
| xmove_fd(cfd, 0); | |
| xdup2(0, 1); | |
| xdup2(0, 2); | |
| IF_NC_EXTRA(BB_EXECVP(execparam[0], execparam);) | |
| - | /* Don't print stuff or it will go over the wire.... */ |
| + | /* Don't print stuff or it will go over the wire... */ |
| _exit(127); | |
| } | |
| - | // Select loop copying stdin to cfd, and cfd to stdout. |
| + | /* Select loop copying stdin to cfd, and cfd to stdout */ |
| FD_ZERO(&readfds); | |
| FD_SET(cfd, &readfds); | |
| @@ -170,11 +168,12 @@ int nc_main(int argc, char **argv) | |
| testfds = readfds; | |
| - | if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0) |
| + | if (select(cfd + 1, &testfds, NULL, NULL, NULL) < 0) |
| bb_perror_msg_and_die("select"); | |
| #define iobuf bb_common_bufsiz1 | |
| - | for (fd = 0; fd < FD_SETSIZE; fd++) { |
| + | fd = STDIN_FILENO; |
| + | while (1) { |
| if (FD_ISSET(fd, &testfds)) { | |
| nread = safe_read(fd, iobuf, sizeof(iobuf)); | |
| if (fd == cfd) { | |
| @@ -182,17 +181,21 @@ int nc_main(int argc, char **argv) | |
| exit(EXIT_SUCCESS); | |
| ofd = STDOUT_FILENO; | |
| } else { | |
| - | if (nread<1) { |
| - | // Close outgoing half-connection so they get EOF, but |
| - | // leave incoming alone so we can see response. |
| + | if (nread < 1) { |
| + | /* Close outgoing half-connection so they get EOF, |
| + | * but leave incoming alone so we can see response */ |
| shutdown(cfd, 1); | |
| FD_CLR(STDIN_FILENO, &readfds); | |
| } | |
| ofd = cfd; | |
| } | |
| xwrite(ofd, iobuf, nread); | |
| - | if (delay > 0) sleep(delay); |
| + | if (delay > 0) |
| + | sleep(delay); |
| } | |
| + | if (fd == cfd) |
| + | break; |
| + | fd = cfd; |
| } | |
| } | |
| } | |