diff options
Diffstat (limited to 'usr.sbin/ppp/exec.c')
-rw-r--r-- | usr.sbin/ppp/exec.c | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/usr.sbin/ppp/exec.c b/usr.sbin/ppp/exec.c new file mode 100644 index 0000000..a53db37 --- /dev/null +++ b/usr.sbin/ppp/exec.c @@ -0,0 +1,410 @@ +/*- + * 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. + * + * $FreeBSD$ + */ + +#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; +} |