/*- * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org> * 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. * * $FreeBSD: src/usr.sbin/ppp/exec.c,v 1.29.10.1.4.1 2010/12/21 17:10:29 kensmith Exp $ */ #include <sys/param.h> #include <sys/socket.h> #include <sys/un.h> #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sysexits.h> #include <sys/wait.h> #include <sys/stat.h> #include <sys/uio.h> #include <termios.h> #include <unistd.h> #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 "main.h" #include "exec.h" struct execdevice { struct device dev; /* What struct physical knows about */ int fd_out; /* output descriptor */ }; #define device2exec(d) ((d)->type == EXEC_DEVICE ? (struct execdevice *)d : NULL) unsigned exec_DeviceSize(void) { return sizeof(struct execdevice); } static void exec_Free(struct physical *p) { struct execdevice *dev = device2exec(p->handler); if (dev->fd_out != -1) close(dev->fd_out); free(dev); } static void exec_device2iov(struct device *d, struct iovec *iov, int *niov, int maxiov __unused, int *auxfd, int *nauxfd) { struct execdevice *dev; int sz = physical_MaxDeviceSize(); iov[*niov].iov_base = d = realloc(d, sz); if (d == NULL) { log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz); AbortProgram(EX_OSERR); } iov[*niov].iov_len = sz; (*niov)++; dev = device2exec(d); if (dev->fd_out >= 0) { *auxfd = dev->fd_out; (*nauxfd)++; } } static int exec_RemoveFromSet(struct physical *p, fd_set *r, fd_set *w, fd_set *e) { struct execdevice *dev = device2exec(p->handler); int sets; p->handler->removefromset = NULL; sets = physical_RemoveFromSet(p, r, w, e); p->handler->removefromset = exec_RemoveFromSet; if (dev->fd_out >= 0) { if (w && FD_ISSET(dev->fd_out, w)) { FD_CLR(dev->fd_out, w); log_Printf(LogTIMER, "%s: fdunset(w) %d\n", p->link.name, dev->fd_out); sets++; } if (e && FD_ISSET(dev->fd_out, e)) { FD_CLR(dev->fd_out, e); log_Printf(LogTIMER, "%s: fdunset(e) %d\n", p->link.name, dev->fd_out); sets++; } } return sets; } static ssize_t exec_Write(struct physical *p, const void *v, size_t n) { struct execdevice *dev = device2exec(p->handler); int fd = dev->fd_out == -1 ? p->fd : dev->fd_out; return write(fd, v, n); } static struct device baseexecdevice = { EXEC_DEVICE, "exec", 0, { CD_NOTREQUIRED, 0 }, NULL, exec_RemoveFromSet, NULL, NULL, NULL, NULL, NULL, exec_Free, NULL, exec_Write, exec_device2iov, NULL, NULL, NULL }; struct device * exec_iov2device(int type, struct physical *p, struct iovec *iov, int *niov, int maxiov __unused, int *auxfd, int *nauxfd) { if (type == EXEC_DEVICE) { struct execdevice *dev = (struct execdevice *)iov[(*niov)++].iov_base; dev = realloc(dev, sizeof *dev); /* Reduce to the correct size */ if (dev == NULL) { log_Printf(LogALERT, "Failed to allocate memory: %d\n", (int)(sizeof *dev)); AbortProgram(EX_OSERR); } if (*nauxfd) { dev->fd_out = *auxfd; (*nauxfd)--; } else dev->fd_out = -1; /* Refresh function pointers etc */ memcpy(&dev->dev, &baseexecdevice, sizeof dev->dev); physical_SetupStack(p, dev->dev.name, PHYSICAL_NOFORCE); return &dev->dev; } return NULL; } static int exec_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n) { struct physical *p = descriptor2physical(d); struct execdevice *dev = device2exec(p->handler); int result = 0; if (w && dev->fd_out >= 0) { FD_SET(dev->fd_out, w); log_Printf(LogTIMER, "%s: fdset(w) %d\n", p->link.name, dev->fd_out); result++; w = NULL; } if (e && dev->fd_out >= 0) { FD_SET(dev->fd_out, e); log_Printf(LogTIMER, "%s: fdset(e) %d\n", p->link.name, dev->fd_out); result++; } if (result && *n <= dev->fd_out) *n = dev->fd_out + 1; return result + physical_doUpdateSet(d, r, w, e, n, 0); } static int exec_IsSet(struct fdescriptor *d, const fd_set *fdset) { struct physical *p = descriptor2physical(d); struct execdevice *dev = device2exec(p->handler); int result = dev->fd_out >= 0 && FD_ISSET(dev->fd_out, fdset); result += physical_IsSet(d, fdset); return result; } struct device * exec_Create(struct physical *p) { struct execdevice *dev; dev = NULL; if (p->fd < 0) { if (*p->name.full == '!') { int fids[2], type; if ((dev = malloc(sizeof *dev)) == NULL) { log_Printf(LogWARN, "%s: Cannot allocate an exec device: %s\n", p->link.name, strerror(errno)); return NULL; } dev->fd_out = -1; 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)); free(dev); dev = NULL; } 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]); close(fids[0]); free(dev); dev = NULL; } 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]); close(fids[0]); 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, 1); 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); } } } } else { struct stat st; if (fstat(p->fd, &st) != -1 && (st.st_mode & S_IFIFO)) { if ((dev = malloc(sizeof *dev)) == NULL) log_Printf(LogWARN, "%s: Cannot allocate an exec device: %s\n", p->link.name, strerror(errno)); else if (p->fd == STDIN_FILENO) { log_Printf(LogPHASE, "%s: Using stdin/stdout to communicate with " "parent (pipe mode)\n", p->link.name); dev->fd_out = dup(STDOUT_FILENO); /* Hook things up so that we monitor dev->fd_out */ p->desc.UpdateSet = exec_UpdateSet; p->desc.IsSet = exec_IsSet; } else dev->fd_out = -1; } } if (dev) { memcpy(&dev->dev, &baseexecdevice, sizeof dev->dev); physical_SetupStack(p, dev->dev.name, PHYSICAL_NOFORCE); if (p->cfg.cd.necessity != CD_DEFAULT) log_Printf(LogWARN, "Carrier settings ignored\n"); return &dev->dev; } return NULL; }