diff options
Diffstat (limited to 'src/initctl/initctl.c')
| -rw-r--r-- | src/initctl/initctl.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/src/initctl/initctl.c b/src/initctl/initctl.c new file mode 100644 index 0000000..260dc2e --- /dev/null +++ b/src/initctl/initctl.c @@ -0,0 +1,405 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <ctype.h> +#include <errno.h> +#include <stdio.h> +#include <sys/epoll.h> +#include <unistd.h> + +#include "sd-bus.h" +#include "sd-daemon.h" + +#include "alloc-util.h" +#include "bus-error.h" +#include "bus-util.h" +#include "def.h" +#include "fd-util.h" +#include "format-util.h" +#include "initreq.h" +#include "list.h" +#include "log.h" +#include "special.h" +#include "util.h" +#include "process-util.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; + + sd_bus *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_MULTI_USER_TARGET, true }, + { '3', SPECIAL_MULTI_USER_TARGET, true }, + { '4', SPECIAL_MULTI_USER_TARGET, true }, + { '5', SPECIAL_GRAPHICAL_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 int change_runlevel(Server *s, int runlevel) { + const char *target; + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + const char *mode; + bool isolate = false; + int r; + + assert(s); + + target = translate_runlevel(runlevel, &isolate); + if (!target) { + log_warning("Got request for unknown runlevel %c, ignoring.", runlevel); + return 0; + } + + if (isolate) + mode = "isolate"; + else + mode = "replace-irreversibly"; + + log_debug("Running request %s/start/%s", target, mode); + + r = sd_bus_call_method( + s->bus, + "org.freedesktop.systemd1", + "/org/freedesktop/systemd1", + "org.freedesktop.systemd1.Manager", + "StartUnit", + &error, + NULL, + "ss", target, mode); + if (r < 0) + return log_error_errno(r, "Failed to change runlevel: %s", bus_error_message(&error, -r)); + + return 0; +} + +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_errno(errno, "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_errno(errno, "kill() failed: %m"); + break; + + default: + (void) 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; + l = read(f->fd, + ((uint8_t*) &f->buffer) + f->bytes_read, + sizeof(f->buffer) - f->bytes_read); + if (l <= 0) { + if (errno == EAGAIN) + return 0; + + return log_warning_errno(errno, "Failed to read from fifo: %m"); + } + + 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, f->server->fifos, f); + } + + if (f->fd >= 0) { + if (f->server) + epoll_ctl(f->server->epoll_fd, EPOLL_CTL_DEL, f->fd, NULL); + + safe_close(f->fd); + } + + free(f); +} + +static void server_done(Server *s) { + assert(s); + + while (s->fifos) + fifo_free(s->fifos); + + s->epoll_fd = safe_close(s->epoll_fd); + s->bus = sd_bus_flush_close_unref(s->bus); +} + +static int server_init(Server *s, unsigned n_sockets) { + int r; + unsigned i; + + assert(s); + assert(n_sockets > 0); + + zero(*s); + + s->epoll_fd = epoll_create1(EPOLL_CLOEXEC); + if (s->epoll_fd < 0) { + r = log_error_errno(errno, + "Failed to create epoll object: %m"); + goto fail; + } + + for (i = 0; i < n_sockets; i++) { + struct epoll_event ev; + Fifo *f; + int fd; + + fd = SD_LISTEN_FDS_START+i; + + r = sd_is_fifo(fd, NULL); + if (r < 0) { + log_error_errno(r, "Failed to determine file descriptor type: %m"); + goto fail; + } + + if (!r) { + log_error("Wrong file descriptor type."); + r = -EINVAL; + goto fail; + } + + f = new0(Fifo, 1); + if (!f) { + r = -ENOMEM; + log_error_errno(errno, "Failed to create fifo object: %m"); + 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_errno(errno, "Failed to add fifo fd to epoll object: %m"); + goto fail; + } + + f->fd = fd; + LIST_PREPEND(fifo, s->fifos, f); + f->server = s; + s->n_fifos++; + } + + r = bus_connect_system_systemd(&s->bus); + if (r < 0) { + log_error_errno(r, "Failed to get D-Bus connection: %m"); + r = -EIO; + goto fail; + } + + return 0; + +fail: + server_done(s); + + return r; +} + +static int process_event(Server *s, struct epoll_event *ev) { + int r; + Fifo *f; + + assert(s); + + if (!(ev->events & EPOLLIN)) + return log_info_errno(SYNTHETIC_ERRNO(EIO), + "Got invalid event from epoll. (3)"); + + f = (Fifo*) ev->data.ptr; + r = fifo_process(f); + if (r < 0) { + log_info_errno(r, "Got error on fifo: %m"); + 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_setup_service(); + + umask(0022); + + n = sd_listen_fds(true); + if (n < 0) { + log_error_errno(r, "Failed to read listening file descriptors from environment: %m"); + 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 "PID_FMT, getpid_cached()); + + sd_notify(false, + "READY=1\n" + "STATUS=Processing requests..."); + + while (!server.quit) { + struct epoll_event event; + int k; + + k = epoll_wait(server.epoll_fd, &event, 1, TIMEOUT_MSEC); + if (k < 0) { + if (errno == EINTR) + continue; + log_error_errno(errno, "epoll_wait() failed: %m"); + goto fail; + } + + if (k <= 0) + break; + + if (process_event(&server, &event) < 0) + goto fail; + } + + r = EXIT_SUCCESS; + + log_debug("systemd-initctl stopped as pid "PID_FMT, getpid_cached()); + +fail: + sd_notify(false, + "STOPPING=1\n" + "STATUS=Shutting down..."); + + server_done(&server); + + return r; +} |