X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=execute.c;h=357fd5c20874aea7a6c670b89f7e737f64aa3fb1;hp=1ca91fddd78f8b1fdea5e431b4b00e968afa62c0;hb=8d567588cad053f79abe603ab113e1b85a92f1da;hpb=47a71eed0f41c8661361d5506e47d1b223613680 diff --git a/execute.c b/execute.c index 1ca91fddd..357fd5c20 100644 --- a/execute.c +++ b/execute.c @@ -1,5 +1,24 @@ /*-*- Mode: C; c-basic-offset: 8 -*-*/ +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see . +***/ + #include #include #include @@ -7,61 +26,26 @@ #include #include #include +#include +#include +#include +#include +#include +#include +#include +#include #include "execute.h" #include "strv.h" #include "macro.h" #include "util.h" #include "log.h" +#include "ioprio.h" +#include "securebits.h" +#include "cgroup.h" -static int close_fds(int except[], unsigned n_except) { - DIR *d; - struct dirent *de; - int r = 0; - - /* Modifies the fds array! (sorts it) */ - - if (!(d = opendir("/proc/self/fd"))) - return -errno; - - while ((de = readdir(d))) { - int fd; - - if (de->d_name[0] == '.') - continue; - - if ((r = safe_atoi(de->d_name, &fd)) < 0) - goto finish; - - if (fd < 3) - continue; - - if (fd == dirfd(d)) - continue; - - if (except) { - bool found; - unsigned i; - - found = false; - for (i = 0; i < n_except; i++) - if (except[i] == fd) { - found = true; - break; - } - - if (found) - continue; - } - - if ((r = close_nointr(fd)) < 0) - goto finish; - } - -finish: - closedir(d); - return r; -} +/* This assumes there is a 'tty' group */ +#define TTY_MODE 0620 static int shift_fds(int fds[], unsigned n_fds) { int start, restart_from; @@ -69,6 +53,8 @@ static int shift_fds(int fds[], unsigned n_fds) { if (n_fds <= 0) return 0; + /* Modifies the fds array! (sorts it) */ + assert(fds); start = 0; @@ -87,7 +73,7 @@ static int shift_fds(int fds[], unsigned n_fds) { if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0) return -errno; - assert_se(close_nointr(fds[i]) == 0); + close_nointr_nofail(fds[i]); fds[i] = nfd; /* Hmm, the fd we wanted isn't free? Then @@ -105,140 +91,969 @@ static int shift_fds(int fds[], unsigned n_fds) { return 0; } -static int flags_fds(int fds[], unsigned n_fds) { +static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) { unsigned i; + int r; if (n_fds <= 0) return 0; assert(fds); - /* Drops O_NONBLOCK and FD_CLOEXEC from the file flags */ + /* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */ for (i = 0; i < n_fds; i++) { - int flags; - if ((flags = fcntl(fds[i], F_GETFL, 0)) < 0) - return -errno; + if ((r = fd_nonblock(fds[i], nonblock)) < 0) + return r; + + /* We unconditionally drop FD_CLOEXEC from the fds, + * since after all we want to pass these fds to our + * children */ + + if ((r = fd_cloexec(fds[i], false)) < 0) + return r; + } + + return 0; +} + +static const char *tty_path(const ExecContext *context) { + assert(context); + + if (context->tty_path) + return context->tty_path; + + return "/dev/console"; +} + +static int open_null_as(int flags, int nfd) { + int fd, r; + + assert(nfd >= 0); + + if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0) + return -errno; + + if (fd != nfd) { + r = dup2(fd, nfd) < 0 ? -errno : nfd; + close_nointr_nofail(fd); + } else + r = nfd; + + return r; +} + +static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, int nfd) { + int fd, r; + union { + struct sockaddr sa; + struct sockaddr_un un; + } sa; + + assert(context); + assert(output < _EXEC_OUTPUT_MAX); + assert(ident); + assert(nfd >= 0); + + if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) + return -errno; + + zero(sa); + sa.sa.sa_family = AF_UNIX; + strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1); + + if (connect(fd, &sa.sa, sizeof(sa)) < 0) { + close_nointr_nofail(fd); + return -errno; + } + + if (shutdown(fd, SHUT_RD) < 0) { + close_nointr_nofail(fd); + return -errno; + } + + /* We speak a very simple protocol between log server + * and client: one line for the log destination (kmsg + * or syslog), followed by the priority field, + * followed by the process name. Since we replaced + * stdin/stderr we simple use stdio to write to + * it. Note that we use stderr, to minimize buffer + * flushing issues. */ + + dprintf(fd, + "%s\n" + "%i\n" + "%s\n", + output == EXEC_OUTPUT_KERNEL ? "kmsg" : "syslog", + context->syslog_priority, + context->syslog_identifier ? context->syslog_identifier : ident); + + if (fd != nfd) { + r = dup2(fd, nfd) < 0 ? -errno : nfd; + close_nointr_nofail(fd); + } else + r = nfd; + + return r; +} +static int open_terminal_as(const char *path, mode_t mode, int nfd) { + int fd, r; + + assert(path); + assert(nfd >= 0); + + if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0) + return fd; + + if (fd != nfd) { + r = dup2(fd, nfd) < 0 ? -errno : nfd; + close_nointr_nofail(fd); + } else + r = nfd; + + return r; +} + +static bool is_terminal_input(ExecInput i) { + return + i == EXEC_INPUT_TTY || + i == EXEC_INPUT_TTY_FORCE || + i == EXEC_INPUT_TTY_FAIL; +} + +static int fixup_input(const ExecContext *context, int socket_fd) { + assert(context); + + if (socket_fd < 0 && context->std_input == EXEC_INPUT_SOCKET) + return EXEC_INPUT_NULL; + + return context->std_input; +} + +static int fixup_output(const ExecContext *context, int socket_fd) { + assert(context); + + if (socket_fd < 0 && context->std_output == EXEC_OUTPUT_SOCKET) + return EXEC_OUTPUT_INHERIT; + + return context->std_output; +} + +static int fixup_error(const ExecContext *context, int socket_fd) { + assert(context); + + if (socket_fd < 0 && context->std_error == EXEC_OUTPUT_SOCKET) + return EXEC_OUTPUT_INHERIT; + + return context->std_error; +} + +static int setup_input(const ExecContext *context, int socket_fd) { + ExecInput i; + + assert(context); + + i = fixup_input(context, socket_fd); + + switch (i) { + + case EXEC_INPUT_NULL: + return open_null_as(O_RDONLY, STDIN_FILENO); + + case EXEC_INPUT_TTY: + case EXEC_INPUT_TTY_FORCE: + case EXEC_INPUT_TTY_FAIL: { + int fd, r; + + if ((fd = acquire_terminal( + tty_path(context), + i == EXEC_INPUT_TTY_FAIL, + i == EXEC_INPUT_TTY_FORCE)) < 0) + return fd; + + if (fd != STDIN_FILENO) { + r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO; + close_nointr_nofail(fd); + } else + r = STDIN_FILENO; + + return r; + } + + case EXEC_INPUT_SOCKET: + return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO; + + default: + assert_not_reached("Unknown input type"); + } +} + +static int setup_output(const ExecContext *context, int socket_fd, const char *ident) { + ExecOutput o; + ExecInput i; + + assert(context); + assert(ident); + + i = fixup_input(context, socket_fd); + o = fixup_output(context, socket_fd); + + /* This expects the input is already set up */ + + switch (o) { + + case EXEC_OUTPUT_INHERIT: + + /* If the input is connected to a terminal, inherit that... */ + if (is_terminal_input(i) || i == EXEC_INPUT_SOCKET) + return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO; + + return STDIN_FILENO; + + case EXEC_OUTPUT_NULL: + return open_null_as(O_WRONLY, STDOUT_FILENO); + + case EXEC_OUTPUT_TTY: + if (is_terminal_input(i)) + return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO; + + /* We don't reset the terminal if this is just about output */ + return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO); + + case EXEC_OUTPUT_SYSLOG: + case EXEC_OUTPUT_KERNEL: + return connect_logger_as(context, o, ident, STDOUT_FILENO); + + case EXEC_OUTPUT_SOCKET: + assert(socket_fd >= 0); + return dup2(socket_fd, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO; + + default: + assert_not_reached("Unknown output type"); + } +} + +static int setup_error(const ExecContext *context, int socket_fd, const char *ident) { + ExecOutput o, e; + ExecInput i; + + assert(context); + assert(ident); + + i = fixup_input(context, socket_fd); + o = fixup_output(context, socket_fd); + e = fixup_error(context, socket_fd); + + /* This expects the input and output are already set up */ + + /* Don't change the stderr file descriptor if we inherit all + * the way and are not on a tty */ + if (e == EXEC_OUTPUT_INHERIT && + o == EXEC_OUTPUT_INHERIT && + !is_terminal_input(i)) + return STDERR_FILENO; + + /* Duplicate form stdout if possible */ + if (e == o || e == EXEC_OUTPUT_INHERIT) + return dup2(STDOUT_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO; + + switch (e) { + + case EXEC_OUTPUT_NULL: + return open_null_as(O_WRONLY, STDERR_FILENO); + + case EXEC_OUTPUT_TTY: + if (is_terminal_input(i)) + return dup2(STDIN_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO; + + /* We don't reset the terminal if this is just about output */ + return open_terminal_as(tty_path(context), O_WRONLY, STDERR_FILENO); + + case EXEC_OUTPUT_SYSLOG: + case EXEC_OUTPUT_KERNEL: + return connect_logger_as(context, e, ident, STDERR_FILENO); + + case EXEC_OUTPUT_SOCKET: + assert(socket_fd >= 0); + return dup2(socket_fd, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO; + + default: + assert_not_reached("Unknown error type"); + } +} + +static int chown_terminal(int fd, uid_t uid) { + struct stat st; + + assert(fd >= 0); + + /* This might fail. What matters are the results. */ + fchown(fd, uid, -1); + fchmod(fd, TTY_MODE); + + if (fstat(fd, &st) < 0) + return -errno; + + if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE) + return -EPERM; + + return 0; +} + +static int setup_confirm_stdio(const ExecContext *context, + int *_saved_stdin, + int *_saved_stdout) { + int fd = -1, saved_stdin, saved_stdout = -1, r; + + assert(context); + assert(_saved_stdin); + assert(_saved_stdout); + + /* This returns positive EXIT_xxx return values instead of + * negative errno style values! */ + + if ((saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3)) < 0) + return EXIT_STDIN; + + if ((saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3)) < 0) { + r = EXIT_STDOUT; + goto fail; + } + + if ((fd = acquire_terminal( + tty_path(context), + context->std_input == EXEC_INPUT_TTY_FAIL, + context->std_input == EXEC_INPUT_TTY_FORCE)) < 0) { + r = EXIT_STDIN; + goto fail; + } + + if (chown_terminal(fd, getuid()) < 0) { + r = EXIT_STDIN; + goto fail; + } + + if (dup2(fd, STDIN_FILENO) < 0) { + r = EXIT_STDIN; + goto fail; + } + + if (dup2(fd, STDOUT_FILENO) < 0) { + r = EXIT_STDOUT; + goto fail; + } + + if (fd >= 2) + close_nointr_nofail(fd); + + *_saved_stdin = saved_stdin; + *_saved_stdout = saved_stdout; + + return 0; + +fail: + if (saved_stdout >= 0) + close_nointr_nofail(saved_stdout); + + if (saved_stdin >= 0) + close_nointr_nofail(saved_stdin); + + if (fd >= 0) + close_nointr_nofail(fd); + + return r; +} + +static int restore_conform_stdio(const ExecContext *context, + int *saved_stdin, + int *saved_stdout, + bool *keep_stdin, + bool *keep_stdout) { + + assert(context); + assert(saved_stdin); + assert(*saved_stdin >= 0); + assert(saved_stdout); + assert(*saved_stdout >= 0); + + /* This returns positive EXIT_xxx return values instead of + * negative errno style values! */ + + if (is_terminal_input(context->std_input)) { + + /* The service wants terminal input. */ + + *keep_stdin = true; + *keep_stdout = + context->std_output == EXEC_OUTPUT_INHERIT || + context->std_output == EXEC_OUTPUT_TTY; + + } else { + /* If the service doesn't want a controlling terminal, + * then we need to get rid entirely of what we have + * already. */ - /* Since we are at it, let's make sure that nobody - * forgot setting O_NONBLOCK for all our fds */ + if (release_terminal() < 0) + return EXIT_STDIN; - if (fcntl(fds[i], F_SETFL, flags &~O_NONBLOCK) < 0) + if (dup2(*saved_stdin, STDIN_FILENO) < 0) + return EXIT_STDIN; + + if (dup2(*saved_stdout, STDOUT_FILENO) < 0) + return EXIT_STDOUT; + + *keep_stdout = *keep_stdin = false; + } + + return 0; +} + +static int get_group_creds(const char *groupname, gid_t *gid) { + struct group *g; + unsigned long lu; + + assert(groupname); + assert(gid); + + /* We enforce some special rules for gid=0: in order to avoid + * NSS lookups for root we hardcode its data. */ + + if (streq(groupname, "root") || streq(groupname, "0")) { + *gid = 0; + return 0; + } + + if (safe_atolu(groupname, &lu) >= 0) { + errno = 0; + g = getgrgid((gid_t) lu); + } else { + errno = 0; + g = getgrnam(groupname); + } + + if (!g) + return errno != 0 ? -errno : -ESRCH; + + *gid = g->gr_gid; + return 0; +} + +static int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home) { + struct passwd *p; + unsigned long lu; + + assert(username); + assert(*username); + assert(uid); + assert(gid); + assert(home); + + /* We enforce some special rules for uid=0: in order to avoid + * NSS lookups for root we hardcode its data. */ + + if (streq(*username, "root") || streq(*username, "0")) { + *username = "root"; + *uid = 0; + *gid = 0; + *home = "/root"; + return 0; + } + + if (safe_atolu(*username, &lu) >= 0) { + errno = 0; + p = getpwuid((uid_t) lu); + + /* If there are multiple users with the same id, make + * sure to leave $USER to the configured value instead + * of the first occurence in the database. However if + * the uid was configured by a numeric uid, then let's + * pick the real username from /etc/passwd. */ + if (*username && p) + *username = p->pw_name; + } else { + errno = 0; + p = getpwnam(*username); + } + + if (!p) + return errno != 0 ? -errno : -ESRCH; + + *uid = p->pw_uid; + *gid = p->pw_gid; + *home = p->pw_dir; + return 0; +} + +static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) { + bool keep_groups = false; + int r; + + assert(context); + + /* Lookup and ser GID and supplementary group list. Here too + * we avoid NSS lookups for gid=0. */ + + if (context->group || username) { + + if (context->group) + if ((r = get_group_creds(context->group, &gid)) < 0) + return r; + + /* First step, initialize groups from /etc/groups */ + if (username && gid != 0) { + if (initgroups(username, gid) < 0) + return -errno; + + keep_groups = true; + } + + /* Second step, set our gids */ + if (setresgid(gid, gid, gid) < 0) return -errno; + } + + if (context->supplementary_groups) { + int ngroups_max, k; + gid_t *gids; + char **i; + + /* Final step, initialize any manually set supplementary groups */ + ngroups_max = (int) sysconf(_SC_NGROUPS_MAX); + + if (!(gids = new(gid_t, ngroups_max))) + return -ENOMEM; - if ((flags = fcntl(fds[i], F_GETFD, 0)) < 0) + if (keep_groups) { + if ((k = getgroups(ngroups_max, gids)) < 0) { + free(gids); + return -errno; + } + } else + k = 0; + + STRV_FOREACH(i, context->supplementary_groups) { + + if (k >= ngroups_max) { + free(gids); + return -E2BIG; + } + + if ((r = get_group_creds(*i, gids+k)) < 0) { + free(gids); + return r; + } + + k++; + } + + if (setgroups(k, gids) < 0) { + free(gids); return -errno; + } + + free(gids); + } - /* Also make sure nobody forgot O_CLOEXEC for all our - * fds */ - if (fcntl(fds[i], F_SETFD, flags &~FD_CLOEXEC) < 0) + return 0; +} + +static int enforce_user(const ExecContext *context, uid_t uid) { + int r; + assert(context); + + /* Sets (but doesn't lookup) the uid and make sure we keep the + * capabilities while doing so. */ + + if (context->capabilities) { + cap_t d; + static const cap_value_t bits[] = { + CAP_SETUID, /* Necessary so that we can run setresuid() below */ + CAP_SETPCAP /* Necessary so that we can set PR_SET_SECUREBITS later on */ + }; + + /* First step: If we need to keep capabilities but + * drop privileges we need to make sure we keep our + * caps, whiel we drop priviliges. */ + if (uid != 0) { + int sb = context->secure_bits|SECURE_KEEP_CAPS; + + if (prctl(PR_GET_SECUREBITS) != sb) + if (prctl(PR_SET_SECUREBITS, sb) < 0) + return -errno; + } + + /* Second step: set the capabilites. This will reduce + * the capabilities to the minimum we need. */ + + if (!(d = cap_dup(context->capabilities))) return -errno; + + if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 || + cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) { + r = -errno; + cap_free(d); + return r; + } + + if (cap_set_proc(d) < 0) { + r = -errno; + cap_free(d); + return r; + } + + cap_free(d); } + /* Third step: actually set the uids */ + if (setresuid(uid, uid, uid) < 0) + return -errno; + + /* At this point we should have all necessary capabilities but + are otherwise a normal user. However, the caps might got + corrupted due to the setresuid() so we need clean them up + later. This is done outside of this call. */ + return 0; } -int exec_spawn(const ExecCommand *command, const ExecContext *context, int *fds, unsigned n_fds, pid_t *ret) { +int exec_spawn(ExecCommand *command, + char **argv, + const ExecContext *context, + int fds[], unsigned n_fds, + bool apply_permissions, + bool apply_chroot, + bool confirm_spawn, + CGroupBonding *cgroup_bondings, + pid_t *ret) { + pid_t pid; + int r; + char *line; + int socket_fd; assert(command); assert(context); assert(ret); assert(fds || n_fds <= 0); - log_debug("about to execute %s", command->path); + if (context->std_input == EXEC_INPUT_SOCKET || + context->std_output == EXEC_OUTPUT_SOCKET || + context->std_error == EXEC_OUTPUT_SOCKET) { + + if (n_fds != 1) + return -EINVAL; + + socket_fd = fds[0]; + + fds = NULL; + n_fds = 0; + } else + socket_fd = -1; + + if (!argv) + argv = command->argv; + + if (!(line = exec_command_line(argv))) + return -ENOMEM; + + log_debug("About to execute: %s", line); + free(line); + + if (cgroup_bondings) + if ((r = cgroup_bonding_realize_list(cgroup_bondings))) + return r; if ((pid = fork()) < 0) return -errno; if (pid == 0) { - char **e, **f = NULL; - int i, r; - char t[16]; + int i; sigset_t ss; + const char *username = NULL, *home = NULL; + uid_t uid = (uid_t) -1; + gid_t gid = (gid_t) -1; + char **our_env = NULL, **final_env = NULL; + unsigned n_env = 0; + int saved_stdout = -1, saved_stdin = -1; + bool keep_stdout = false, keep_stdin = false; /* child */ + reset_all_signal_handlers(); + if (sigemptyset(&ss) < 0 || sigprocmask(SIG_SETMASK, &ss, NULL) < 0) { r = EXIT_SIGNAL_MASK; goto fail; } + if (!context->no_setsid) + if (setsid() < 0) { + r = EXIT_SETSID; + goto fail; + } + umask(context->umask); - if (chdir(context->directory ? context->directory : "/") < 0) { - r = EXIT_CHDIR; - goto fail; + if (confirm_spawn) { + char response; + + /* Set up terminal for the question */ + if ((r = setup_confirm_stdio(context, + &saved_stdin, &saved_stdout))) + goto fail; + + /* Now ask the question. */ + if (!(line = exec_command_line(argv))) { + r = EXIT_MEMORY; + goto fail; + } + + r = ask(&response, "yns", "Execute %s? [Yes, No, Skip] ", line); + free(line); + + if (r < 0 || response == 'n') { + r = EXIT_CONFIRM; + goto fail; + } else if (response == 's') { + r = 0; + goto fail; + } + + /* Release terminal for the question */ + if ((r = restore_conform_stdio(context, + &saved_stdin, &saved_stdout, + &keep_stdin, &keep_stdout))) + goto fail; } - snprintf(t, sizeof(t), "%i", context->oom_adjust); - char_array_0(t); + if (!keep_stdin) + if (setup_input(context, socket_fd) < 0) { + r = EXIT_STDIN; + goto fail; + } - if (write_one_line_file("/proc/self/oom_adj", t) < 0) { - r = EXIT_OOM_ADJUST; + if (!keep_stdout) + if (setup_output(context, socket_fd, file_name_from_path(command->path)) < 0) { + r = EXIT_STDOUT; + goto fail; + } + + if (setup_error(context, socket_fd, file_name_from_path(command->path)) < 0) { + r = EXIT_STDERR; goto fail; } - if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) { - r = EXIT_NICE; - goto fail; + if (cgroup_bondings) + if ((r = cgroup_bonding_install_list(cgroup_bondings, 0)) < 0) { + r = EXIT_CGROUP; + goto fail; + } + + if (context->oom_adjust_set) { + char t[16]; + + snprintf(t, sizeof(t), "%i", context->oom_adjust); + char_array_0(t); + + if (write_one_line_file("/proc/self/oom_adj", t) < 0) { + r = EXIT_OOM_ADJUST; + goto fail; + } } - if (close_fds(fds, n_fds) < 0 || - shift_fds(fds, n_fds) < 0 || - flags_fds(fds, n_fds) < 0) { - r = EXIT_FDS; - goto fail; + if (context->nice_set) + if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) { + r = EXIT_NICE; + goto fail; + } + + if (context->cpu_sched_set) { + struct sched_param param; + + zero(param); + param.sched_priority = context->cpu_sched_priority; + + if (sched_setscheduler(0, context->cpu_sched_policy | + (context->cpu_sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0), ¶m) < 0) { + r = EXIT_SETSCHEDULER; + goto fail; + } } - for (i = 0; i < RLIMIT_NLIMITS; i++) { - if (!context->rlimit[i]) - continue; + if (context->cpu_affinity_set) + if (sched_setaffinity(0, sizeof(context->cpu_affinity), &context->cpu_affinity) < 0) { + r = EXIT_CPUAFFINITY; + goto fail; + } + + if (context->ioprio_set) + if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) { + r = EXIT_IOPRIO; + goto fail; + } + + if (context->timer_slack_ns_set) + if (prctl(PR_SET_TIMERSLACK, context->timer_slack_ns_set) < 0) { + r = EXIT_TIMERSLACK; + goto fail; + } - if (setrlimit(i, context->rlimit[i]) < 0) { - r = EXIT_LIMITS; + if (context->user) { + username = context->user; + if (get_user_creds(&username, &uid, &gid, &home) < 0) { + r = EXIT_USER; goto fail; } + + if (is_terminal_input(context->std_input)) + if (chown_terminal(STDIN_FILENO, uid) < 0) { + r = EXIT_STDIN; + goto fail; + } } - if (n_fds > 0) { - char a[64], b[64]; - char *listen_env[3] = { - a, - b, - NULL - }; + if (apply_permissions) + if (enforce_groups(context, username, uid) < 0) { + r = EXIT_GROUP; + goto fail; + } - snprintf(a, sizeof(a), "LISTEN_PID=%llu", (unsigned long long) getpid()); - snprintf(b, sizeof(b), "LISTEN_FDS=%u", n_fds); + if (apply_chroot) { + if (context->root_directory) + if (chroot(context->root_directory) < 0) { + r = EXIT_CHROOT; + goto fail; + } - a[sizeof(a)-1] = 0; - b[sizeof(b)-1] = 0; + if (chdir(context->working_directory ? context->working_directory : "/") < 0) { + r = EXIT_CHDIR; + goto fail; + } + } else { + + char *d; - if (context->environment) { - if (!(f = strv_merge(listen_env, context->environment))) { - r = EXIT_MEMORY; + if (asprintf(&d, "%s/%s", + context->root_directory ? context->root_directory : "", + context->working_directory ? context->working_directory : "") < 0) { + r = EXIT_MEMORY; + goto fail; + } + + if (chdir(d) < 0) { + free(d); + r = EXIT_CHDIR; + goto fail; + } + + free(d); + } + + if (close_all_fds(fds, n_fds) < 0 || + shift_fds(fds, n_fds) < 0 || + flags_fds(fds, n_fds, context->non_blocking) < 0) { + r = EXIT_FDS; + goto fail; + } + + if (apply_permissions) { + + for (i = 0; i < RLIMIT_NLIMITS; i++) { + if (!context->rlimit[i]) + continue; + + if (setrlimit(i, context->rlimit[i]) < 0) { + r = EXIT_LIMITS; goto fail; } - e = f; - } else - e = listen_env; + } - } else - e = context->environment; + if (context->user) + if (enforce_user(context, uid) < 0) { + r = EXIT_USER; + goto fail; + } - execve(command->path, command->argv, e); + /* PR_GET_SECUREBITS is not priviliged, while + * PR_SET_SECUREBITS is. So to suppress + * potential EPERMs we'll try not to call + * PR_SET_SECUREBITS unless necessary. */ + if (prctl(PR_GET_SECUREBITS) != context->secure_bits) + if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) { + r = EXIT_SECUREBITS; + goto fail; + } + + if (context->capabilities) + if (cap_set_proc(context->capabilities) < 0) { + r = EXIT_CAPABILITIES; + goto fail; + } + } + + if (!(our_env = new0(char*, 6))) { + r = EXIT_MEMORY; + goto fail; + } + + if (n_fds > 0) + if (asprintf(our_env + n_env++, "LISTEN_PID=%llu", (unsigned long long) getpid()) < 0 || + asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) { + r = EXIT_MEMORY; + goto fail; + } + + if (home) + if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) { + r = EXIT_MEMORY; + goto fail; + } + + if (username) + if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 || + asprintf(our_env + n_env++, "USER=%s", username) < 0) { + r = EXIT_MEMORY; + goto fail; + } + + if (!(final_env = strv_env_merge(environ, our_env, context->environment, NULL))) { + r = EXIT_MEMORY; + goto fail; + } + + execve(command->path, argv, final_env); r = EXIT_EXEC; fail: - strv_free(f); + strv_free(our_env); + strv_free(final_env); + + if (saved_stdin >= 0) + close_nointr_nofail(saved_stdin); + + if (saved_stdout >= 0) + close_nointr_nofail(saved_stdout); + _exit(r); } + /* We add the new process to the cgroup both in the child (so + * that we can be sure that no user code is ever executed + * outside of the cgroup) and in the parent (so that we can be + * sure that when we kill the cgroup the process will be + * killed too). */ + if (cgroup_bondings) + if ((r = cgroup_bonding_install_list(cgroup_bondings, pid)) < 0) { + r = EXIT_CGROUP; + goto fail; + } - log_debug("executed %s as %llu", command->path, (unsigned long long) pid); + log_debug("Forked %s as %llu", command->path, (unsigned long long) pid); + + command->exec_status.pid = pid; + command->exec_status.start_timestamp = now(CLOCK_REALTIME); *ret = pid; return 0; @@ -248,9 +1063,30 @@ void exec_context_init(ExecContext *c) { assert(c); c->umask = 0002; - cap_clear(c->capabilities); c->oom_adjust = 0; + c->oom_adjust_set = false; c->nice = 0; + c->nice_set = false; + c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0); + c->ioprio_set = false; + c->cpu_sched_policy = SCHED_OTHER; + c->cpu_sched_priority = 0; + c->cpu_sched_set = false; + CPU_ZERO(&c->cpu_affinity); + c->cpu_affinity_set = false; + c->timer_slack_ns = 0; + c->timer_slack_ns_set = false; + + c->cpu_sched_reset_on_fork = false; + c->non_blocking = false; + + c->std_input = 0; + c->std_output = 0; + c->std_error = 0; + c->syslog_priority = LOG_DAEMON|LOG_INFO; + + c->secure_bits = 0; + c->capability_bounding_set_drop = 0; } void exec_context_done(ExecContext *c) { @@ -266,8 +1102,16 @@ void exec_context_done(ExecContext *c) { c->rlimit[l] = NULL; } - free(c->directory); - c->directory = NULL; + free(c->working_directory); + c->working_directory = NULL; + free(c->root_directory); + c->root_directory = NULL; + + free(c->tty_path); + c->tty_path = NULL; + + free(c->syslog_identifier); + c->syslog_identifier = NULL; free(c->user); c->user = NULL; @@ -277,6 +1121,28 @@ void exec_context_done(ExecContext *c) { strv_free(c->supplementary_groups); c->supplementary_groups = NULL; + + if (c->capabilities) { + cap_free(c->capabilities); + c->capabilities = NULL; + } +} + +void exec_command_done(ExecCommand *c) { + assert(c); + + free(c->path); + c->path = NULL; + + strv_free(c->argv); + c->argv = NULL; +} + +void exec_command_done_array(ExecCommand *c, unsigned n) { + unsigned i; + + for (i = 0; i < n; i++) + exec_command_done(c+i); } void exec_command_free_list(ExecCommand *c) { @@ -284,9 +1150,7 @@ void exec_command_free_list(ExecCommand *c) { while ((i = c)) { LIST_REMOVE(ExecCommand, command, c, i); - - free(i->path); - strv_free(i->argv); + exec_command_done(i); free(i); } } @@ -301,6 +1165,9 @@ void exec_command_free_array(ExecCommand **c, unsigned n) { } void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) { + char ** e; + unsigned i; + assert(c); assert(f); @@ -308,42 +1175,190 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) { prefix = ""; fprintf(f, - "%sUmask: %04o\n" - "%sDirectory: %s\n" - "%sNice: %i\n" - "%sOOMAdjust: %i\n", + "%sUMask: %04o\n" + "%sWorkingDirectory: %s\n" + "%sRootDirectory: %s\n" + "%sNonBlocking: %s\n", prefix, c->umask, - prefix, c->directory ? c->directory : "/", - prefix, c->nice, - prefix, c->oom_adjust); + prefix, c->working_directory ? c->working_directory : "/", + prefix, c->root_directory ? c->root_directory : "/", + prefix, yes_no(c->non_blocking)); + + if (c->environment) + for (e = c->environment; *e; e++) + fprintf(f, "%sEnvironment: %s\n", prefix, *e); + + if (c->nice_set) + fprintf(f, + "%sNice: %i\n", + prefix, c->nice); + + if (c->oom_adjust_set) + fprintf(f, + "%sOOMAdjust: %i\n", + prefix, c->oom_adjust); + + for (i = 0; i < RLIM_NLIMITS; i++) + if (c->rlimit[i]) + fprintf(f, "%s%s: %llu\n", prefix, rlimit_to_string(i), (unsigned long long) c->rlimit[i]->rlim_max); + + if (c->ioprio_set) + fprintf(f, + "%sIOSchedulingClass: %s\n" + "%sIOPriority: %i\n", + prefix, ioprio_class_to_string(IOPRIO_PRIO_CLASS(c->ioprio)), + prefix, (int) IOPRIO_PRIO_DATA(c->ioprio)); + + if (c->cpu_sched_set) + fprintf(f, + "%sCPUSchedulingPolicy: %s\n" + "%sCPUSchedulingPriority: %i\n" + "%sCPUSchedulingResetOnFork: %s\n", + prefix, sched_policy_to_string(c->cpu_sched_policy), + prefix, c->cpu_sched_priority, + prefix, yes_no(c->cpu_sched_reset_on_fork)); + + if (c->cpu_affinity_set) { + fprintf(f, "%sCPUAffinity:", prefix); + for (i = 0; i < CPU_SETSIZE; i++) + if (CPU_ISSET(i, &c->cpu_affinity)) + fprintf(f, " %i", i); + fputs("\n", f); + } + + if (c->timer_slack_ns_set) + fprintf(f, "%sTimerSlackNS: %lu\n", prefix, c->timer_slack_ns); + + fprintf(f, + "%sStandardInput: %s\n" + "%sStandardOutput: %s\n" + "%sStandardError: %s\n", + prefix, exec_input_to_string(c->std_input), + prefix, exec_output_to_string(c->std_output), + prefix, exec_output_to_string(c->std_error)); + + if (c->tty_path) + fprintf(f, + "%sTTYPath: %s\n", + prefix, c->tty_path); + + if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KERNEL || + c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KERNEL) + fprintf(f, + "%sSyslogFacility: %s\n" + "%sSyslogLevel: %s\n", + prefix, log_facility_to_string(LOG_FAC(c->syslog_priority)), + prefix, log_level_to_string(LOG_PRI(c->syslog_priority))); + + if (c->capabilities) { + char *t; + if ((t = cap_to_text(c->capabilities, NULL))) { + fprintf(f, "%sCapabilities: %s\n", + prefix, t); + cap_free(t); + } + } + + if (c->secure_bits) + fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n", + prefix, + (c->secure_bits & SECURE_KEEP_CAPS) ? " keep-caps" : "", + (c->secure_bits & SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "", + (c->secure_bits & SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "", + (c->secure_bits & SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "", + (c->secure_bits & SECURE_NOROOT) ? " noroot" : "", + (c->secure_bits & SECURE_NOROOT_LOCKED) ? "noroot-locked" : ""); + + if (c->capability_bounding_set_drop) { + fprintf(f, "%sCapabilityBoundingSetDrop:", prefix); + + for (i = 0; i <= CAP_LAST_CAP; i++) + if (c->capability_bounding_set_drop & (1 << i)) { + char *t; + + if ((t = cap_to_name(i))) { + fprintf(f, " %s", t); + free(t); + } + } + + fputs("\n", f); + } + + if (c->user) + fprintf(f, "%sUser: %s", prefix, c->user); + if (c->group) + fprintf(f, "%sGroup: %s", prefix, c->group); + + if (c->supplementary_groups) { + char **g; + + fprintf(f, "%sSupplementaryGroups:", prefix); + + STRV_FOREACH(g, c->supplementary_groups) + fprintf(f, " %s", *g); + + fputs("\n", f); + } } void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) { assert(s); s->pid = pid; + s->exit_timestamp = now(CLOCK_REALTIME); + s->code = code; s->status = status; - s->timestamp = now(CLOCK_REALTIME); } -char *exec_command_line(ExecCommand *c) { +void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) { + char buf[FORMAT_TIMESTAMP_MAX]; + + assert(s); + assert(f); + + if (!prefix) + prefix = ""; + + if (s->pid <= 0) + return; + + fprintf(f, + "%sPID: %llu\n", + prefix, (unsigned long long) s->pid); + + if (s->start_timestamp > 0) + fprintf(f, + "%sStart Timestamp: %s\n", + prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp)); + + if (s->exit_timestamp > 0) + fprintf(f, + "%sExit Timestamp: %s\n" + "%sExit Code: %s\n" + "%sExit Status: %i\n", + prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp), + prefix, sigchld_code_to_string(s->code), + prefix, s->status); +} + +char *exec_command_line(char **argv) { size_t k; char *n, *p, **a; bool first = true; - assert(c); - assert(c->argv); + assert(argv); k = 1; - STRV_FOREACH(a, c->argv) + STRV_FOREACH(a, argv) k += strlen(*a)+3; if (!(n = new(char, k))) return NULL; p = n; - STRV_FOREACH(a, c->argv) { + STRV_FOREACH(a, argv) { if (!first) *(p++) = ' '; @@ -368,6 +1383,9 @@ char *exec_command_line(ExecCommand *c) { } void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) { + char *p2; + const char *prefix2; + char *cmd; assert(c); @@ -375,14 +1393,20 @@ void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) { if (!prefix) prefix = ""; + p2 = strappend(prefix, "\t"); + prefix2 = p2 ? p2 : prefix; - cmd = exec_command_line(c); + cmd = exec_command_line(c->argv); fprintf(f, "%sCommand Line: %s\n", prefix, cmd ? cmd : strerror(ENOMEM)); free(cmd); + + exec_status_dump(&c->exec_status, f, prefix2); + + free(p2); } void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) { @@ -394,3 +1418,171 @@ void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) { LIST_FOREACH(command, c, c) exec_command_dump(c, f, prefix); } + +void exec_command_append_list(ExecCommand **l, ExecCommand *e) { + ExecCommand *end; + + assert(l); + assert(e); + + if (*l) { + /* It's kinda important that we keep the order here */ + LIST_FIND_TAIL(ExecCommand, command, *l, end); + LIST_INSERT_AFTER(ExecCommand, command, *l, end, e); + } else + *l = e; +} + +int exec_command_set(ExecCommand *c, const char *path, ...) { + va_list ap; + char **l, *p; + + assert(c); + assert(path); + + va_start(ap, path); + l = strv_new_ap(path, ap); + va_end(ap); + + if (!l) + return -ENOMEM; + + if (!(p = strdup(path))) { + strv_free(l); + return -ENOMEM; + } + + free(c->path); + c->path = p; + + strv_free(c->argv); + c->argv = l; + + return 0; +} + +const char* exit_status_to_string(ExitStatus status) { + + /* We cast to int here, so that -Wenum doesn't complain that + * EXIT_SUCCESS/EXIT_FAILURE aren't in the enum */ + + switch ((int) status) { + + case EXIT_SUCCESS: + return "SUCCESS"; + + case EXIT_FAILURE: + return "FAILURE"; + + case EXIT_INVALIDARGUMENT: + return "INVALIDARGUMENT"; + + case EXIT_NOTIMPLEMENTED: + return "NOTIMPLEMENTED"; + + case EXIT_NOPERMISSION: + return "NOPERMISSION"; + + case EXIT_NOTINSTALLED: + return "NOTINSSTALLED"; + + case EXIT_NOTCONFIGURED: + return "NOTCONFIGURED"; + + case EXIT_NOTRUNNING: + return "NOTRUNNING"; + + case EXIT_CHDIR: + return "CHDIR"; + + case EXIT_NICE: + return "NICE"; + + case EXIT_FDS: + return "FDS"; + + case EXIT_EXEC: + return "EXEC"; + + case EXIT_MEMORY: + return "MEMORY"; + + case EXIT_LIMITS: + return "LIMITS"; + + case EXIT_OOM_ADJUST: + return "OOM_ADJUST"; + + case EXIT_SIGNAL_MASK: + return "SIGNAL_MASK"; + + case EXIT_STDIN: + return "STDIN"; + + case EXIT_STDOUT: + return "STDOUT"; + + case EXIT_CHROOT: + return "CHROOT"; + + case EXIT_IOPRIO: + return "IOPRIO"; + + case EXIT_TIMERSLACK: + return "TIMERSLACK"; + + case EXIT_SECUREBITS: + return "SECUREBITS"; + + case EXIT_SETSCHEDULER: + return "SETSCHEDULER"; + + case EXIT_CPUAFFINITY: + return "CPUAFFINITY"; + + case EXIT_GROUP: + return "GROUP"; + + case EXIT_USER: + return "USER"; + + case EXIT_CAPABILITIES: + return "CAPABILITIES"; + + case EXIT_CGROUP: + return "CGROUP"; + + case EXIT_SETSID: + return "SETSID"; + + case EXIT_CONFIRM: + return "CONFIRM"; + + case EXIT_STDERR: + return "STDERR"; + + default: + return NULL; + } +} + +static const char* const exec_input_table[_EXEC_INPUT_MAX] = { + [EXEC_INPUT_NULL] = "null", + [EXEC_INPUT_TTY] = "tty", + [EXEC_INPUT_TTY_FORCE] = "tty-force", + [EXEC_INPUT_TTY_FAIL] = "tty-fail", + [EXEC_INPUT_SOCKET] = "socket" +}; + +static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = { + [EXEC_OUTPUT_INHERIT] = "inherit", + [EXEC_OUTPUT_NULL] = "null", + [EXEC_OUTPUT_TTY] = "tty", + [EXEC_OUTPUT_SYSLOG] = "syslog", + [EXEC_OUTPUT_KERNEL] = "kernel", + [EXEC_OUTPUT_SOCKET] = "socket" +}; + +DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput); + +DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);