diff options
Diffstat (limited to 'src/initctl.c')
| -rw-r--r-- | src/initctl.c | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/src/initctl.c b/src/initctl.c new file mode 100644 index 0000000000..53d03a9e10 --- /dev/null +++ b/src/initctl.c @@ -0,0 +1,451 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + 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 <http://www.gnu.org/licenses/>. +***/ + +#include <sys/socket.h> +#include <sys/types.h> +#include <assert.h> +#include <time.h> +#include <string.h> +#include <stdio.h> +#include <errno.h> +#include <unistd.h> +#include <sys/poll.h> +#include <sys/epoll.h> +#include <sys/un.h> +#include <fcntl.h> +#include <ctype.h> + +#include <dbus/dbus.h> +#include <systemd/sd-daemon.h> + +#include "util.h" +#include "log.h" +#include "list.h" +#include "initreq.h" +#include "special.h" +#include "dbus-common.h" +#include "def.h" + +#define SERVER_FD_MAX 16 +#define TIMEOUT_MSEC ((int) (DEFAULT_EXIT_USEC/USEC_PER_MSEC)) + +typedef struct Fifo Fifo; + +typedef struct Server { + int epoll_fd; + + LIST_HEAD(Fifo, fifos); + unsigned n_fifos; + + DBusConnection *bus; + + bool quit; +} Server; + +struct Fifo { + Server *server; + + int fd; + + struct init_request buffer; + size_t bytes_read; + + LIST_FIELDS(Fifo, fifo); +}; + +static const char *translate_runlevel(int runlevel, bool *isolate) { + static const struct { + const int runlevel; + const char *special; + bool isolate; + } table[] = { + { '0', SPECIAL_POWEROFF_TARGET, false }, + { '1', SPECIAL_RESCUE_TARGET, true }, + { 's', SPECIAL_RESCUE_TARGET, true }, + { 'S', SPECIAL_RESCUE_TARGET, true }, + { '2', SPECIAL_RUNLEVEL2_TARGET, true }, + { '3', SPECIAL_RUNLEVEL3_TARGET, true }, + { '4', SPECIAL_RUNLEVEL4_TARGET, true }, + { '5', SPECIAL_RUNLEVEL5_TARGET, true }, + { '6', SPECIAL_REBOOT_TARGET, false }, + }; + + unsigned i; + + assert(isolate); + + for (i = 0; i < ELEMENTSOF(table); i++) + if (table[i].runlevel == runlevel) { + *isolate = table[i].isolate; + if (runlevel == '6' && kexec_loaded()) + return SPECIAL_KEXEC_TARGET; + return table[i].special; + } + + return NULL; +} + +static void change_runlevel(Server *s, int runlevel) { + const char *target; + DBusMessage *m = NULL, *reply = NULL; + DBusError error; + const char *mode; + bool isolate = false; + + assert(s); + + dbus_error_init(&error); + + if (!(target = translate_runlevel(runlevel, &isolate))) { + log_warning("Got request for unknown runlevel %c, ignoring.", runlevel); + goto finish; + } + + if (isolate) + mode = "isolate"; + else + mode = "replace"; + + log_debug("Running request %s/start/%s", target, mode); + + if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartUnit"))) { + log_error("Could not allocate message."); + goto finish; + } + + if (!dbus_message_append_args(m, + DBUS_TYPE_STRING, &target, + DBUS_TYPE_STRING, &mode, + DBUS_TYPE_INVALID)) { + log_error("Could not attach target and flag information to message."); + goto finish; + } + + if (!(reply = dbus_connection_send_with_reply_and_block(s->bus, m, -1, &error))) { + log_error("Failed to start unit: %s", bus_error_message(&error)); + goto finish; + } + +finish: + if (m) + dbus_message_unref(m); + + if (reply) + dbus_message_unref(reply); + + dbus_error_free(&error); +} + +static void request_process(Server *s, const struct init_request *req) { + assert(s); + assert(req); + + if (req->magic != INIT_MAGIC) { + log_error("Got initctl request with invalid magic. Ignoring."); + return; + } + + switch (req->cmd) { + + case INIT_CMD_RUNLVL: + if (!isprint(req->runlevel)) + log_error("Got invalid runlevel. Ignoring."); + else + switch (req->runlevel) { + + /* we are async anyway, so just use kill for reexec/reload */ + case 'u': + case 'U': + if (kill(1, SIGTERM) < 0) + log_error("kill() failed: %m"); + + /* The bus connection will be + * terminated if PID 1 is reexecuted, + * hence let's just exit here, and + * rely on that we'll be restarted on + * the next request */ + s->quit = true; + break; + + case 'q': + case 'Q': + if (kill(1, SIGHUP) < 0) + log_error("kill() failed: %m"); + break; + + default: + change_runlevel(s, req->runlevel); + } + return; + + case INIT_CMD_POWERFAIL: + case INIT_CMD_POWERFAILNOW: + case INIT_CMD_POWEROK: + log_warning("Received UPS/power initctl request. This is not implemented in systemd. Upgrade your UPS daemon!"); + return; + + case INIT_CMD_CHANGECONS: + log_warning("Received console change initctl request. This is not implemented in systemd."); + return; + + case INIT_CMD_SETENV: + case INIT_CMD_UNSETENV: + log_warning("Received environment initctl request. This is not implemented in systemd."); + return; + + default: + log_warning("Received unknown initctl request. Ignoring."); + return; + } +} + +static int fifo_process(Fifo *f) { + ssize_t l; + + assert(f); + + errno = EIO; + if ((l = read(f->fd, ((uint8_t*) &f->buffer) + f->bytes_read, sizeof(f->buffer) - f->bytes_read)) <= 0) { + + if (errno == EAGAIN) + return 0; + + log_warning("Failed to read from fifo: %s", strerror(errno)); + return -1; + } + + f->bytes_read += l; + assert(f->bytes_read <= sizeof(f->buffer)); + + if (f->bytes_read == sizeof(f->buffer)) { + request_process(f->server, &f->buffer); + f->bytes_read = 0; + } + + return 0; +} + +static void fifo_free(Fifo *f) { + assert(f); + + if (f->server) { + assert(f->server->n_fifos > 0); + f->server->n_fifos--; + LIST_REMOVE(Fifo, fifo, f->server->fifos, f); + } + + if (f->fd >= 0) { + if (f->server) + epoll_ctl(f->server->epoll_fd, EPOLL_CTL_DEL, f->fd, NULL); + + close_nointr_nofail(f->fd); + } + + free(f); +} + +static void server_done(Server *s) { + assert(s); + + while (s->fifos) + fifo_free(s->fifos); + + if (s->epoll_fd >= 0) + close_nointr_nofail(s->epoll_fd); + + if (s->bus) { + dbus_connection_flush(s->bus); + dbus_connection_close(s->bus); + dbus_connection_unref(s->bus); + } +} + +static int server_init(Server *s, unsigned n_sockets) { + int r; + unsigned i; + DBusError error; + + assert(s); + assert(n_sockets > 0); + + dbus_error_init(&error); + + zero(*s); + + if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) { + r = -errno; + log_error("Failed to create epoll object: %s", strerror(errno)); + goto fail; + } + + for (i = 0; i < n_sockets; i++) { + struct epoll_event ev; + Fifo *f; + int fd; + + fd = SD_LISTEN_FDS_START+i; + + if ((r = sd_is_fifo(fd, NULL)) < 0) { + log_error("Failed to determine file descriptor type: %s", strerror(-r)); + goto fail; + } + + if (!r) { + log_error("Wrong file descriptor type."); + r = -EINVAL; + goto fail; + } + + if (!(f = new0(Fifo, 1))) { + r = -ENOMEM; + log_error("Failed to create fifo object: %s", strerror(errno)); + goto fail; + } + + f->fd = -1; + + zero(ev); + ev.events = EPOLLIN; + ev.data.ptr = f; + if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) { + r = -errno; + fifo_free(f); + log_error("Failed to add fifo fd to epoll object: %s", strerror(errno)); + goto fail; + } + + f->fd = fd; + LIST_PREPEND(Fifo, fifo, s->fifos, f); + f->server = s; + s->n_fifos ++; + } + + if (bus_connect(DBUS_BUS_SYSTEM, &s->bus, NULL, &error) < 0) { + log_error("Failed to get D-Bus connection: %s", bus_error_message(&error)); + goto fail; + } + + return 0; + +fail: + server_done(s); + + dbus_error_free(&error); + return r; +} + +static int process_event(Server *s, struct epoll_event *ev) { + int r; + Fifo *f; + + assert(s); + + if (!(ev->events & EPOLLIN)) { + log_info("Got invalid event from epoll. (3)"); + return -EIO; + } + + f = (Fifo*) ev->data.ptr; + + if ((r = fifo_process(f)) < 0) { + log_info("Got error on fifo: %s", strerror(-r)); + fifo_free(f); + return r; + } + + return 0; +} + +int main(int argc, char *argv[]) { + Server server; + int r = EXIT_FAILURE, n; + + if (getppid() != 1) { + log_error("This program should be invoked by init only."); + return EXIT_FAILURE; + } + + if (argc > 1) { + log_error("This program does not take arguments."); + return EXIT_FAILURE; + } + + log_set_target(LOG_TARGET_AUTO); + log_parse_environment(); + log_open(); + + umask(0022); + + if ((n = sd_listen_fds(true)) < 0) { + log_error("Failed to read listening file descriptors from environment: %s", strerror(-r)); + return EXIT_FAILURE; + } + + if (n <= 0 || n > SERVER_FD_MAX) { + log_error("No or too many file descriptors passed."); + return EXIT_FAILURE; + } + + if (server_init(&server, (unsigned) n) < 0) + return EXIT_FAILURE; + + log_debug("systemd-initctl running as pid %lu", (unsigned long) getpid()); + + sd_notify(false, + "READY=1\n" + "STATUS=Processing requests..."); + + while (!server.quit) { + struct epoll_event event; + int k; + + if ((k = epoll_wait(server.epoll_fd, + &event, 1, + TIMEOUT_MSEC)) < 0) { + + if (errno == EINTR) + continue; + + log_error("epoll_wait() failed: %s", strerror(errno)); + goto fail; + } + + if (k <= 0) + break; + + if (process_event(&server, &event) < 0) + goto fail; + } + + r = EXIT_SUCCESS; + + log_debug("systemd-initctl stopped as pid %lu", (unsigned long) getpid()); + +fail: + sd_notify(false, + "STATUS=Shutting down..."); + + server_done(&server); + + dbus_shutdown(); + + return r; +} |