/*- * Copyright (c) 1999 Brian Somers * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $OpenBSD: exec.c,v 1.19 2013/04/29 00:28:23 okan Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include "layer.h" #include "defs.h" #include "mbuf.h" #include "log.h" #include "timer.h" #include "lqr.h" #include "hdlc.h" #include "throughput.h" #include "fsm.h" #include "lcp.h" #include "ccp.h" #include "link.h" #include "async.h" #include "descriptor.h" #include "physical.h" #include "mp.h" #include "chat.h" #include "command.h" #include "auth.h" #include "chap.h" #include "cbcp.h" #include "datalink.h" #include "id.h" #include "exec.h" static struct device execdevice = { EXEC_DEVICE, "exec", 0, { CD_NOTREQUIRED, 0 }, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }; struct device * exec_iov2device(int type, struct physical *p, struct iovec *iov, int *niov, int maxiov, int *auxfd, int *nauxfd) { if (type == EXEC_DEVICE) { free(iov[(*niov)++].iov_base); physical_SetupStack(p, execdevice.name, PHYSICAL_NOFORCE); return &execdevice; } return NULL; } struct device * exec_Create(struct physical *p) { if (p->fd < 0 && *p->name.full == '!') { int fids[2], type; p->fd--; /* We own the device but maybe can't use it - change fd */ type = physical_IsSync(p) ? SOCK_DGRAM : SOCK_STREAM; if (socketpair(AF_UNIX, type, PF_UNSPEC, fids) < 0) log_Printf(LogPHASE, "Unable to create pipe for line exec: %s\n", strerror(errno)); else { static int child_status; /* This variable is abused ! */ int stat, argc, i, ret, wret, pidpipe[2]; pid_t pid, realpid; char *argv[MAXARGS]; stat = fcntl(fids[0], F_GETFL, 0); if (stat > 0) { stat |= O_NONBLOCK; fcntl(fids[0], F_SETFL, stat); } realpid = getpid(); if (pipe(pidpipe) == -1) { log_Printf(LogPHASE, "Unable to pipe for line exec: %s\n", strerror(errno)); close(fids[1]); } else switch ((pid = fork())) { case -1: log_Printf(LogPHASE, "Unable to fork for line exec: %s\n", strerror(errno)); close(pidpipe[0]); close(pidpipe[1]); close(fids[1]); break; case 0: close(pidpipe[0]); close(fids[0]); timer_TermService(); #ifndef NOSUID setuid(ID0realuid()); #endif child_status = 0; switch ((pid = vfork())) { case 0: close(pidpipe[1]); break; case -1: ret = errno; log_Printf(LogPHASE, "Unable to vfork to drop parent: %s\n", strerror(errno)); close(pidpipe[1]); _exit(ret); default: write(pidpipe[1], &pid, sizeof pid); close(pidpipe[1]); _exit(child_status); /* The error from exec() ! */ } log_Printf(LogDEBUG, "Exec'ing ``%s''\n", p->name.base); if ((argc = MakeArgs(p->name.base, argv, VECSIZE(argv), PARSE_REDUCE|PARSE_NOHASH)) < 0) { log_Printf(LogWARN, "Syntax error in exec command\n"); _exit(ESRCH); } command_Expand(argv, argc, (char const *const *)argv, p->dl->bundle, 0, realpid); dup2(fids[1], STDIN_FILENO); dup2(fids[1], STDOUT_FILENO); dup2(fids[1], STDERR_FILENO); for (i = getdtablesize(); i > STDERR_FILENO; i--) fcntl(i, F_SETFD, FD_CLOEXEC); execvp(*argv, argv); child_status = errno; /* Only works for vfork() */ printf("execvp failed: %s: %s\r\n", *argv, strerror(child_status)); _exit(child_status); break; default: close(pidpipe[1]); close(fids[1]); if (read(pidpipe[0], &p->session_owner, sizeof p->session_owner) != sizeof p->session_owner) p->session_owner = (pid_t)-1; close(pidpipe[0]); while ((wret = waitpid(pid, &stat, 0)) == -1 && errno == EINTR) ; if (wret == -1) { log_Printf(LogWARN, "Waiting for child process: %s\n", strerror(errno)); close(fids[0]); p->session_owner = (pid_t)-1; break; } else if (WIFSIGNALED(stat)) { log_Printf(LogWARN, "Child process received sig %d !\n", WTERMSIG(stat)); close(fids[0]); p->session_owner = (pid_t)-1; break; } else if (WIFSTOPPED(stat)) { log_Printf(LogWARN, "Child process received stop sig %d !\n", WSTOPSIG(stat)); /* I guess that's ok.... */ } else if ((ret = WEXITSTATUS(stat))) { log_Printf(LogWARN, "Cannot exec \"%s\": %s\n", p->name.base, strerror(ret)); close(fids[0]); p->session_owner = (pid_t)-1; break; } p->fd = fids[0]; log_Printf(LogDEBUG, "Using descriptor %d for child\n", p->fd); physical_SetupStack(p, execdevice.name, PHYSICAL_NOFORCE); if (p->cfg.cd.necessity != CD_DEFAULT) log_Printf(LogWARN, "Carrier settings ignored\n"); return &execdevice; } close(fids[0]); } } return NULL; }