diff options
Diffstat (limited to 'usr.sbin/jail/command.c')
-rw-r--r-- | usr.sbin/jail/command.c | 675 |
1 files changed, 675 insertions, 0 deletions
diff --git a/usr.sbin/jail/command.c b/usr.sbin/jail/command.c new file mode 100644 index 0000000..437096a --- /dev/null +++ b/usr.sbin/jail/command.c @@ -0,0 +1,675 @@ +/*- + * Copyright (c) 2010 James Gritton + * 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/event.h> +#include <sys/stat.h> +#include <sys/sysctl.h> +#include <sys/user.h> +#include <sys/wait.h> + +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <kvm.h> +#include <login_cap.h> +#include <paths.h> +#include <pwd.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "jailp.h" + +#define COMSTRING_DUMMY ((struct cfstring *)1) +#define DEFAULT_STOP_TIMEOUT 10 +#define PHASH_SIZE 256 + +LIST_HEAD(phhead, phash); + +struct phash { + LIST_ENTRY(phash) le; + struct cfjail *j; + pid_t pid; +}; + +extern char **environ; + +static int get_user_info(struct cfjail *j, const char *username, + const struct passwd **pwdp, login_cap_t **lcapp); +static void add_proc(struct cfjail *j, pid_t pid); +static void clear_procs(struct cfjail *j); +static struct cfjail *find_proc(pid_t pid); + +static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping); +static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable); +static struct phhead phash[PHASH_SIZE]; +static int kq; + +/* + * Run a command associated with a jail, possibly inside the jail. + */ +int +run_command(struct cfjail *j, int *plimit, enum intparam comparam) +{ + const struct passwd *pwd; + struct cfstring *comstring, *s; + login_cap_t *lcap; + char **argv; + char *cs, *addr, *comcs; + const char *jidstr, *conslog, *path, *ruleset, *term, *username; + size_t comlen; + pid_t pid; + int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout; + + static char *cleanenv; + + if (comparam) { + if (comparam == IP_MOUNT_DEVFS + ? !bool_param(j->intparams[IP_MOUNT_DEVFS]) + : j->intparams[comparam] == NULL) + return 0; + j->comparam = comparam; + j->comstring = comparam == IP_MOUNT_DEVFS ? COMSTRING_DUMMY + : STAILQ_FIRST(&j->intparams[comparam]->val); + } else { + comparam = j->comparam; + if (!(j->flags & JF_RUNQ)) + j->comstring = j->comstring == COMSTRING_DUMMY + ? NULL : STAILQ_NEXT(j->comstring, tq); + } + comstring = j->comstring; + if (comstring == NULL || + (comstring != COMSTRING_DUMMY && comstring->len == 0)) + return 0; + if (plimit && *plimit == 0) { + j->flags |= JF_RUNQ; + requeue(j, &runnable); + return 1; + } + j->flags &= ~(JF_RUNQ | JF_BACKGROUND); + /* + * Collect exec arguments. Internal commands for network and + * mounting build their own argument lists (XXX they should be + * truly internal). + */ + bg = j->flags & JF_FAILED; + down = j->flags & (JF_STOP | JF_FAILED); + if (comparam == IP__IP4_IFADDR) { + argv = alloca(8 * sizeof(char *)); + *(const char **)&argv[0] = _PATH_IFCONFIG; + if ((cs = strchr(comstring->s, '|'))) { + argv[1] = alloca(cs - comstring->s + 1); + strlcpy(argv[1], comstring->s, cs - comstring->s + 1); + addr = cs + 1; + } else { + *(const char **)&argv[1] = + string_param(j->intparams[IP_INTERFACE]); + addr = comstring->s; + } + *(const char **)&argv[2] = "inet"; + if (!(cs = strchr(addr, '/'))) { + argv[3] = addr; + *(const char **)&argv[4] = "netmask"; + *(const char **)&argv[5] = "255.255.255.255"; + argc = 6; + } else if (strchr(cs + 1, '.')) { + argv[3] = alloca(cs - addr + 1); + strlcpy(argv[3], addr, cs - addr + 1); + *(const char **)&argv[4] = "netmask"; + *(const char **)&argv[5] = cs + 1; + argc = 6; + } else { + argv[3] = addr; + argc = 4; + } + *(const char **)&argv[argc] = down ? "-alias" : "alias"; + argv[argc + 1] = NULL; + j->flags |= JF_IFUP; +#ifdef INET6 + } else if (comparam == IP__IP6_IFADDR) { + argv = alloca(8 * sizeof(char *)); + *(const char **)&argv[0] = _PATH_IFCONFIG; + if ((cs = strchr(comstring->s, '|'))) { + argv[1] = alloca(cs - comstring->s + 1); + strlcpy(argv[1], comstring->s, cs - comstring->s + 1); + addr = cs + 1; + } else { + *(const char **)&argv[1] = + string_param(j->intparams[IP_INTERFACE]); + addr = comstring->s; + } + *(const char **)&argv[2] = "inet6"; + argv[3] = addr; + if (!(cs = strchr(addr, '/'))) { + *(const char **)&argv[4] = "prefixlen"; + *(const char **)&argv[5] = "128"; + argc = 6; + } else + argc = 4; + *(const char **)&argv[argc] = down ? "-alias" : "alias"; + argv[argc + 1] = NULL; + j->flags |= JF_IFUP; +#endif + } else if (comparam == IP_VNET_INTERFACE) { + argv = alloca(5 * sizeof(char *)); + *(const char **)&argv[0] = _PATH_IFCONFIG; + argv[1] = comstring->s; + *(const char **)&argv[2] = down ? "-vnet" : "vnet"; + jidstr = string_param(j->intparams[KP_JID]); + *(const char **)&argv[3] = + jidstr ? jidstr : string_param(j->intparams[KP_NAME]); + argv[4] = NULL; + j->flags |= JF_IFUP; + } else if (comparam == IP_MOUNT) { + argv = alloca(8 * sizeof(char *)); + comcs = alloca(comstring->len + 1); + strcpy(comcs, comstring->s); + argc = 0; + for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4; + cs = strtok(NULL, " \t\f\v\r\n")) + argv[argc++] = cs; + if (argc < 3) { + jail_warnx(j, "mount: %s: missing information", + comstring->s); + failed(j); + return -1; + } + if (down) { + argv[4] = NULL; + argv[3] = argv[1]; + *(const char **)&argv[0] = "/sbin/umount"; + } else { + if (argc == 4) { + argv[7] = NULL; + argv[6] = argv[1]; + argv[5] = argv[0]; + argv[4] = argv[3]; + *(const char **)&argv[3] = "-o"; + } else { + argv[5] = NULL; + argv[4] = argv[1]; + argv[3] = argv[0]; + } + *(const char **)&argv[0] = _PATH_MOUNT; + } + *(const char **)&argv[1] = "-t"; + j->flags |= JF_MOUNTED; + } else if (comparam == IP_MOUNT_FSTAB) { + argv = alloca(4 * sizeof(char *)); + *(const char **)&argv[0] = down ? "/sbin/umount" : _PATH_MOUNT; + *(const char **)&argv[1] = "-aF"; + argv[2] = comstring->s; + argv[3] = NULL; + j->flags |= JF_MOUNTED; + } else if (comparam == IP_MOUNT_DEVFS) { + path = string_param(j->intparams[KP_PATH]); + if (path == NULL) { + jail_warnx(j, "mount.devfs: no path"); + failed(j); + return -1; + } + if (down) { + argv = alloca(3 * sizeof(char *)); + *(const char **)&argv[0] = "/sbin/umount"; + argv[1] = alloca(strlen(path) + 5); + sprintf(argv[1], "%s/dev", path); + argv[2] = NULL; + } else { + argv = alloca(4 * sizeof(char *)); + *(const char **)&argv[0] = _PATH_BSHELL; + *(const char **)&argv[1] = "-c"; + ruleset = string_param(j->intparams + [IP_MOUNT_DEVFS_RULESET]); + argv[2] = alloca(strlen(path) + + (ruleset ? strlen(ruleset) + 1 : 0) + 56); + sprintf(argv[2], ". /etc/rc.subr; load_rc_config .; " + "devfs_mount_jail %s/dev%s%s", path, + ruleset ? " " : "", ruleset ? ruleset : ""); + argv[3] = NULL; + } + j->flags |= JF_MOUNTED; + } else if (comparam == IP_COMMAND && j->name == NULL) { + argc = 0; + STAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq) + argc++; + argv = alloca((argc + 1) * sizeof(char *)); + argc = 0; + STAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq) + argv[argc++] = s->s; + argv[argc] = NULL; + j->comstring = NULL; + } else if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) && + !(cs[0] == '&' && cs[1] == '\0')) { + argv = alloca(4 * sizeof(char *)); + *(const char **)&argv[0] = _PATH_BSHELL; + *(const char **)&argv[1] = "-c"; + argv[2] = comstring->s; + argv[3] = NULL; + } else { + if (cs) { + *cs = 0; + bg = 1; + } + comcs = alloca(comstring->len + 1); + strcpy(comcs, comstring->s); + argc = 0; + for (cs = strtok(comcs, " \t\f\v\r\n"); cs; + cs = strtok(NULL, " \t\f\v\r\n")) + argc++; + argv = alloca((argc + 1) * sizeof(char *)); + strcpy(comcs, comstring->s); + argc = 0; + for (cs = strtok(comcs, " \t\f\v\r\n"); cs; + cs = strtok(NULL, " \t\f\v\r\n")) + argv[argc++] = cs; + argv[argc] = NULL; + } + if (argv[0] == NULL) + return 0; + + j->pstatus = 0; + if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) && + timeout != 0) { + clock_gettime(CLOCK_REALTIME, &j->timeout); + j->timeout.tv_sec += timeout; + } else + j->timeout.tv_sec = 0; + + injail = comparam == IP_EXEC_START || comparam == IP_COMMAND || + comparam == IP_EXEC_STOP; + clean = bool_param(j->intparams[IP_EXEC_CLEAN]); + username = string_param(j->intparams[injail + ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]); + sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]); + + consfd = 0; + if (injail && + (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) { + consfd = + open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE); + if (consfd < 0) { + jail_warnx(j, "open %s: %s", conslog, strerror(errno)); + failed(j); + return -1; + } + } + + comlen = 0; + for (i = 0; argv[i]; i++) + comlen += strlen(argv[i]) + 1; + j->comline = cs = emalloc(comlen); + for (i = 0; argv[i]; i++) { + strcpy(cs, argv[i]); + if (argv[i + 1]) { + cs += strlen(argv[i]) + 1; + cs[-1] = ' '; + } + } + if (verbose > 0) + jail_note(j, "run command%s%s%s: %s\n", + injail ? " in jail" : "", username ? " as " : "", + username ? username : "", j->comline); + + pid = fork(); + if (pid < 0) + err(1, "fork"); + if (pid > 0) { + if (bg) { + j->flags |= JF_BACKGROUND; + requeue(j, &ready); + } else { + --*plimit; + add_proc(j, pid); + } + return 1; + } + if (bg) + setsid(); + + pwd = NULL; + lcap = NULL; + if ((clean || username) && injail && sjuser && + get_user_info(j, username, &pwd, &lcap) < 0) + exit(1); + if (injail) { + /* jail_attach won't chdir along with its chroot. */ + path = string_param(j->intparams[KP_PATH]); + if (path && chdir(path) < 0) { + jail_warnx(j, "chdir %s: %s", path, strerror(errno)); + exit(1); + } + if (int_param(j->intparams[IP_EXEC_FIB], &fib) && + setfib(fib) < 0) { + jail_warnx(j, "setfib: %s", strerror(errno)); + exit(1); + } + if (jail_attach(j->jid) < 0) { + jail_warnx(j, "jail_attach: %s", strerror(errno)); + exit(1); + } + } + if (clean || username) { + if (!(injail && sjuser) && + get_user_info(j, username, &pwd, &lcap) < 0) + exit(1); + if (clean) { + term = getenv("TERM"); + environ = &cleanenv; + setenv("PATH", "/bin:/usr/bin", 0); + setenv("TERM", term, 1); + } + if (setusercontext(lcap, pwd, pwd->pw_uid, username + ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN + : LOGIN_SETPATH | LOGIN_SETENV) < 0) { + jail_warnx(j, "setusercontext %s: %s", pwd->pw_name, + strerror(errno)); + exit(1); + } + login_close(lcap); + setenv("USER", pwd->pw_name, 1); + setenv("HOME", pwd->pw_dir, 1); + setenv("SHELL", + *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1); + if (clean && chdir(pwd->pw_dir) < 0) { + jail_warnx(j, "chdir %s: %s", + pwd->pw_dir, strerror(errno)); + exit(1); + } + endpwent(); + } + + if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) { + jail_warnx(j, "exec.consolelog: %s", strerror(errno)); + exit(1); + } + closefrom(3); + execvp(argv[0], argv); + jail_warnx(j, "exec %s: %s", argv[0], strerror(errno)); + exit(1); +} + +/* + * Check command exit status + */ +int +finish_command(struct cfjail *j, int *plimit) +{ + int error; + + if (j->flags & (JF_RUNQ | JF_BACKGROUND)) + return 0; + ++*plimit; + if (!TAILQ_EMPTY(&runnable)) + requeue(TAILQ_FIRST(&runnable), &ready); + error = 0; + if (j->flags & JF_TIMEOUT) { + j->flags &= ~JF_TIMEOUT; + if (j->comparam != IP_STOP_TIMEOUT) { + jail_warnx(j, "%s: timed out", j->comline); + failed(j); + error = -1; + } else if (verbose > 0) + jail_note(j, "timed out\n"); + } else if (j->pstatus != 0) { + if (WIFSIGNALED(j->pstatus)) + jail_warnx(j, "%s: exited on signal %d", + j->comline, WTERMSIG(j->pstatus)); + else + jail_warnx(j, "%s: failed", j->comline); + failed(j); + error = -1; + } + free(j->comline); + return error; +} + +/* + * Check for finished processed or timeouts. + */ +struct cfjail * +next_proc(int nonblock) +{ + struct kevent ke; + struct timespec ts; + struct timespec *tsp; + struct cfjail *j; + + if (!TAILQ_EMPTY(&sleeping)) { + again: + tsp = NULL; + if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) { + clock_gettime(CLOCK_REALTIME, &ts); + ts.tv_sec = j->timeout.tv_sec - ts.tv_sec; + ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec; + if (ts.tv_nsec < 0) { + ts.tv_sec--; + ts.tv_nsec += 1000000000; + } + if (ts.tv_sec < 0 || + (ts.tv_sec == 0 && ts.tv_nsec == 0)) { + j->flags |= JF_TIMEOUT; + clear_procs(j); + return j; + } + tsp = &ts; + } + if (nonblock) { + ts.tv_sec = 0; + ts.tv_nsec = 0; + tsp = &ts; + } + switch (kevent(kq, NULL, 0, &ke, 1, tsp)) { + case -1: + if (errno != EINTR) + err(1, "kevent"); + goto again; + case 0: + if (!nonblock) { + j = TAILQ_FIRST(&sleeping); + j->flags |= JF_TIMEOUT; + clear_procs(j); + return j; + } + break; + case 1: + (void)waitpid(ke.ident, NULL, WNOHANG); + if ((j = find_proc(ke.ident))) { + j->pstatus = ke.data; + return j; + } + goto again; + } + } + return NULL; +} + +/* + * Send SIGTERM to all processes in a jail and wait for them to die. + */ +int +term_procs(struct cfjail *j) +{ + struct kinfo_proc *ki; + int i, noted, pcnt, timeout; + + static kvm_t *kd; + + if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout)) + timeout = DEFAULT_STOP_TIMEOUT; + else if (timeout == 0) + return 0; + + if (kd == NULL) { + kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "jail"); + if (kd == NULL) + exit(1); + } + + ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt); + if (ki == NULL) + exit(1); + noted = 0; + for (i = 0; i < pcnt; i++) + if (ki[i].ki_jid == j->jid && + kill(ki[i].ki_pid, SIGTERM) == 0) { + add_proc(j, ki[i].ki_pid); + if (verbose > 0) { + if (!noted) { + noted = 1; + jail_note(j, "sent SIGTERM to:"); + } + printf(" %d", ki[i].ki_pid); + } + } + if (noted) + printf("\n"); + if (j->nprocs > 0) { + clock_gettime(CLOCK_REALTIME, &j->timeout); + j->timeout.tv_sec += timeout; + return 1; + } + return 0; +} + +/* + * Add a process to the hash, tied to a jail. + */ +static void +add_proc(struct cfjail *j, pid_t pid) +{ + struct kevent ke; + struct cfjail *tj; + struct phash *ph; + + if (!kq && (kq = kqueue()) < 0) + err(1, "kqueue"); + EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL); + if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) + err(1, "kevent"); + ph = emalloc(sizeof(struct phash)); + ph->j = j; + ph->pid = pid; + LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le); + j->nprocs++; + if (j->timeout.tv_sec) { + TAILQ_REMOVE(j->queue, j, tq); + TAILQ_FOREACH(tj, &sleeping, tq) { + if (!tj->timeout.tv_sec || + j->timeout.tv_sec < tj->timeout.tv_sec || + (j->timeout.tv_sec == tj->timeout.tv_sec && + j->timeout.tv_nsec <= tj->timeout.tv_nsec)) { + TAILQ_INSERT_BEFORE(tj, j, tq); + break; + } + } + if (tj == NULL) + TAILQ_INSERT_TAIL(&sleeping, j, tq); + j->queue = &sleeping; + } else + requeue(j, &sleeping); +} + +/* + * Remove any processes from the hash that correspond to a jail. + */ +static void +clear_procs(struct cfjail *j) +{ + struct kevent ke; + struct phash *ph, *tph; + int i; + + j->nprocs = 0; + for (i = 0; i < PHASH_SIZE; i++) + LIST_FOREACH_SAFE(ph, &phash[i], le, tph) + if (ph->j == j) { + EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE, + NOTE_EXIT, 0, NULL); + (void)kevent(kq, &ke, 1, NULL, 0, NULL); + LIST_REMOVE(ph, le); + free(ph); + } +} + +/* + * Find the jail that corresponds to an exited process. + */ +static struct cfjail * +find_proc(pid_t pid) +{ + struct cfjail *j; + struct phash *ph; + + LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le) + if (ph->pid == pid) { + j = ph->j; + LIST_REMOVE(ph, le); + free(ph); + return --j->nprocs ? NULL : j; + } + return NULL; +} + +/* + * Look up a user in the passwd and login.conf files. + */ +static int +get_user_info(struct cfjail *j, const char *username, + const struct passwd **pwdp, login_cap_t **lcapp) +{ + const struct passwd *pwd; + + *pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid()); + if (pwd == NULL) { + if (errno) + jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "", + username ? username : "", strerror(errno)); + else if (username) + jail_warnx(j, "%s: no such user", username); + else + jail_warnx(j, "unknown uid %d", getuid()); + return -1; + } + *lcapp = login_getpwclass(pwd); + if (*lcapp == NULL) { + jail_warnx(j, "getpwclass %s: %s", pwd->pw_name, + strerror(errno)); + return -1; + } + /* Set the groups while the group file is still available */ + if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) { + jail_warnx(j, "initgroups %s: %s", pwd->pw_name, + strerror(errno)); + return -1; + } + return 0; +} |