diff options
Diffstat (limited to 'usr.sbin/cron/cron/popen.c')
| -rw-r--r-- | usr.sbin/cron/cron/popen.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/usr.sbin/cron/cron/popen.c b/usr.sbin/cron/cron/popen.c new file mode 100644 index 0000000..57b1f77 --- /dev/null +++ b/usr.sbin/cron/cron/popen.c @@ -0,0 +1,246 @@ +/* + * Copyright (c) 1988 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software written by Ken Arnold and + * published in UNIX Review, Vol. 6, No. 8. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + */ + +/* this came out of the ftpd sources; it's been modified to avoid the + * globbing stuff since we don't need it. also execvp instead of execv. + */ + +#ifndef lint +#if 0 +static char sccsid[] = "@(#)popen.c 5.7 (Berkeley) 2/14/89"; +#endif +static const char rcsid[] = + "$FreeBSD$"; +#endif /* not lint */ + +#include "cron.h" +#include <sys/signal.h> +#include <fcntl.h> +#include <paths.h> +#if defined(SYSLOG) +# include <syslog.h> +#endif +#if defined(LOGIN_CAP) +# include <login_cap.h> +#endif + + +#define MAX_ARGS 100 +#define WANT_GLOBBING 0 + +/* + * Special version of popen which avoids call to shell. This insures noone + * may create a pipe to a hidden program as a side effect of a list or dir + * command. + */ +static PID_T *pids; +static int fds; + +FILE * +cron_popen(program, type, e) + char *program, *type; + entry *e; +{ + register char *cp; + FILE *iop; + int argc, pdes[2]; + PID_T pid; + char *usernm; + char *argv[MAX_ARGS + 1]; +# if defined(LOGIN_CAP) + struct passwd *pwd; + login_cap_t *lc; +# endif +#if WANT_GLOBBING + char **pop, *vv[2]; + int gargc; + char *gargv[1000]; + extern char **glob(), **copyblk(); +#endif + + if ((*type != 'r' && *type != 'w') || type[1]) + return(NULL); + + if (!pids) { + if ((fds = getdtablesize()) <= 0) + return(NULL); + if (!(pids = calloc(fds, sizeof(PID_T)))) + return(NULL); + } + if (pipe(pdes) < 0) + return(NULL); + + /* break up string into pieces */ + for (argc = 0, cp = program; argc < MAX_ARGS; cp = NULL) + if (!(argv[argc++] = strtok(cp, " \t\n"))) + break; + argv[MAX_ARGS] = NULL; + +#if WANT_GLOBBING + /* glob each piece */ + gargv[0] = argv[0]; + for (gargc = argc = 1; argv[argc]; argc++) { + if (!(pop = glob(argv[argc]))) { /* globbing failed */ + vv[0] = argv[argc]; + vv[1] = NULL; + pop = copyblk(vv); + } + argv[argc] = (char *)pop; /* save to free later */ + while (*pop && gargc < 1000) + gargv[gargc++] = *pop++; + } + gargv[gargc] = NULL; +#endif + + iop = NULL; + switch(pid = vfork()) { + case -1: /* error */ + (void)close(pdes[0]); + (void)close(pdes[1]); + goto pfree; + /* NOTREACHED */ + case 0: /* child */ + if (e != NULL) { +#ifdef SYSLOG + closelog(); +#endif + + /* get new pgrp, void tty, etc. + */ + (void) setsid(); + } + if (*type == 'r') { + /* Do not share our parent's stdin */ + (void)close(0); + (void)open(_PATH_DEVNULL, O_RDWR); + if (pdes[1] != 1) { + dup2(pdes[1], 1); + dup2(pdes[1], 2); /* stderr, too! */ + (void)close(pdes[1]); + } + (void)close(pdes[0]); + } else { + if (pdes[0] != 0) { + dup2(pdes[0], 0); + (void)close(pdes[0]); + } + /* Hack: stdout gets revoked */ + (void)close(1); + (void)open(_PATH_DEVNULL, O_RDWR); + (void)close(2); + (void)open(_PATH_DEVNULL, O_RDWR); + (void)close(pdes[1]); + } + if (e != NULL) { + /* Set user's entire context, but skip the environment + * as cron provides a separate interface for this + */ + usernm = env_get("LOGNAME", e->envp); +# if defined(LOGIN_CAP) + if ((pwd = getpwnam(usernm)) == NULL) + pwd = getpwuid(e->uid); + lc = NULL; + if (pwd != NULL) { + pwd->pw_gid = e->gid; + if (e->class != NULL) + lc = login_getclass(e->class); + } + if (pwd && + setusercontext(lc, pwd, e->uid, + LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETENV)) == 0) + (void) endpwent(); + else { + /* fall back to the old method */ + (void) endpwent(); +# endif + /* + * Set our directory, uid and gid. Set gid + * first since once we set uid, we've lost + * root privileges. + */ + if (setgid(e->gid) != 0) + _exit(ERROR_EXIT); +# if defined(BSD) + if (initgroups(usernm, e->gid) != 0) + _exit(ERROR_EXIT); +# endif + if (setlogin(usernm) != 0) + _exit(ERROR_EXIT); + if (setuid(e->uid) != 0) + _exit(ERROR_EXIT); + /* we aren't root after this..*/ +#if defined(LOGIN_CAP) + } + if (lc != NULL) + login_close(lc); +#endif + chdir(env_get("HOME", e->envp)); + } +#if WANT_GLOBBING + execvp(gargv[0], gargv); +#else + execvp(argv[0], argv); +#endif + _exit(1); + } + /* parent; assume fdopen can't fail... */ + if (*type == 'r') { + iop = fdopen(pdes[0], type); + (void)close(pdes[1]); + } else { + iop = fdopen(pdes[1], type); + (void)close(pdes[0]); + } + pids[fileno(iop)] = pid; + +pfree: +#if WANT_GLOBBING + for (argc = 1; argv[argc] != NULL; argc++) { +/* blkfree((char **)argv[argc]); */ + free((char *)argv[argc]); + } +#endif + return(iop); +} + +int +cron_pclose(iop) + FILE *iop; +{ + register int fdes; + int omask; + WAIT_T stat_loc; + PID_T pid; + + /* + * pclose returns -1 if stream is not associated with a + * `popened' command, or, if already `pclosed'. + */ + if (pids == 0 || pids[fdes = fileno(iop)] == 0) + return(-1); + (void)fclose(iop); + omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP)); + while ((pid = wait(&stat_loc)) != pids[fdes] && pid != -1) + ; + (void)sigsetmask(omask); + pids[fdes] = 0; + return (pid == -1 ? -1 : WEXITSTATUS(stat_loc)); +} |
