sysv: implement /dev/initctl compatibility

1 files changed, 437 insertions, 0 deletions

diff --git a/initctl.c b/initctl.c
new file mode 100644
index 0000000000..a4356759c2
--- /dev/null
+++ b/initctl.c
@@ -0,0 +1,437 @@
+/*-*- 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 <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 "util.h"
+#include "log.h"
+#include "list.h"
+#include "initreq.h"
+
+#define SERVER_FD_START 3
+#define SERVER_FD_MAX 16
+#define TIMEOUT ((int) (10*MSEC_PER_SEC))
+
+typedef struct Fifo Fifo;
+
+typedef struct Server {
+        int epoll_fd;
+
+        LIST_HEAD(Fifo, fifos);
+        unsigned n_fifos;
+
+        DBusConnection *bus;
+} 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) {
+
+        switch (runlevel) {
+
+        case '0':
+                return "halt.target";
+
+        case '1':
+        case 's':
+        case 'S':
+                return "rescue.target";
+
+        case '2':
+                return "runlevel2.target";
+
+        case '3':
+                return "runlevel3.target";
+
+        case '4':
+                return "runlevel4.target";
+
+        case '5':
+                return "runlevel5.target";
+
+        case '6':
+                return "reboot.target";
+
+        default:
+                return NULL;
+        }
+}
+
+static void change_runlevel(Server *s, int runlevel) {
+        const char *target;
+        DBusMessage *m = NULL, *reply = NULL;
+        DBusError error;
+        const char *path, *replace = "replace";
+
+        assert(s);
+
+        dbus_error_init(&error);
+
+        if (!(target = translate_runlevel(runlevel))) {
+                log_warning("Got request for unknown runlevel %c, ignoring.", runlevel);
+                goto finish;
+        }
+
+        log_debug("Running request %s", target);
+
+        if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1", "GetUnit"))) {
+                log_error("Could not allocate message.");
+                goto finish;
+        }
+
+        if (!dbus_message_append_args(m,
+                                      DBUS_TYPE_STRING, &target,
+                                      DBUS_TYPE_INVALID)) {
+                log_error("Could not attach group information to signal message.");
+                goto finish;
+        }
+
+        if (!(reply = dbus_connection_send_with_reply_and_block(s->bus, m, -1, &error))) {
+                log_error("Failed to get unit path: %s", error.message);
+                goto finish;
+        }
+
+        if (!dbus_message_get_args(reply, &error,
+                                   DBUS_TYPE_OBJECT_PATH, &path,
+                                   DBUS_TYPE_INVALID)) {
+                log_error("Failed to parse unit path: %s", error.message);
+                goto finish;
+        }
+
+        dbus_message_unref(m);
+        if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", path, "org.freedesktop.systemd1.Unit", "Start"))) {
+                log_error("Could not allocate message.");
+                goto finish;
+        }
+
+        if (!dbus_message_append_args(m,
+                                      DBUS_TYPE_STRING, &replace,
+                                      DBUS_TYPE_INVALID)) {
+                log_error("Could not attach group information to signal message.");
+                goto finish;
+        }
+
+        dbus_message_unref(reply);
+        if (!(reply = dbus_connection_send_with_reply_and_block(s->bus, m, -1, &error))) {
+                log_error("Failed to start unit: %s", error.message);
+                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
+                        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);
+
+                assert_se(close_nointr(f->fd) == 0);
+        }
+
+        free(f);
+}
+
+static int verify_environment(unsigned *n_sockets) {
+        unsigned long long pid;
+        const char *e;
+        int r;
+        unsigned ns;
+
+        assert_se(n_sockets);
+
+        if (!(e = getenv("LISTEN_PID"))) {
+                log_error("Missing $LISTEN_PID environment variable.");
+                return -ENOENT;
+        }
+
+        if ((r = safe_atollu(e, &pid)) < 0) {
+                log_error("Failed to parse $LISTEN_PID: %s", strerror(-r));
+                return r;
+        }
+
+        if (pid != (unsigned long long) getpid()) {
+                log_error("Socket nor for me.");
+                return -ENOENT;
+        }
+
+        if (!(e = getenv("LISTEN_FDS"))) {
+                log_error("Missing $LISTEN_FDS environment variable.");
+                return -ENOENT;
+        }
+
+        if ((r = safe_atou(e, &ns)) < 0) {
+                log_error("Failed to parse $LISTEN_FDS: %s", strerror(-r));
+                return -E2BIG;
+        }
+
+        if (ns <= 0 || ns > SERVER_FD_MAX) {
+                log_error("Wrong number of file descriptors passed: %s", e);
+                return -E2BIG;
+        }
+
+        *n_sockets = ns;
+
+        return 0;
+}
+
+static void server_done(Server *s) {
+        assert(s);
+
+        while (s->fifos)
+                fifo_free(s->fifos);
+
+        if (s->epoll_fd >= 0)
+                assert_se(close_nointr(s->epoll_fd) == 0);
+
+        if (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;
+
+                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, SERVER_FD_START+i, &ev) < 0) {
+                        r = -errno;
+                        fifo_free(f);
+                        log_error("Failed to add fifo fd to epoll object: %s", strerror(errno));
+                        goto fail;
+                }
+
+                f->fd = SERVER_FD_START+i;
+                LIST_PREPEND(Fifo, fifo, s->fifos, f);
+                f->server = s;
+                s->n_fifos ++;
+        }
+
+        if (!(s->bus = dbus_bus_get(DBUS_BUS_SYSTEM, &error))) {
+                log_error("Failed to get D-Bus connection: %s", error.message);
+                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 = 3;
+        unsigned n;
+
+        log_info("systemd-initctl running as pid %llu", (unsigned long long) getpid());
+
+        if (verify_environment(&n) < 0)
+                return 1;
+
+        if (server_init(&server, n) < 0)
+                return 2;
+
+        for (;;) {
+                struct epoll_event event;
+                int k;
+
+                if ((k = epoll_wait(server.epoll_fd,
+                                    &event, 1,
+                                    TIMEOUT)) < 0) {
+
+                        if (errno == EINTR)
+                                continue;
+
+                        log_error("epoll_wait() failed: %s", strerror(errno));
+                        goto fail;
+                }
+
+                if (k <= 0)
+                        break;
+
+                if ((k = process_event(&server, &event)) < 0)
+                        goto fail;
+        }
+        r = 0;
+
+fail:
+        server_done(&server);
+
+        log_info("systemd-initctl stopped as pid %llu", (unsigned long long) getpid());
+
+        dbus_shutdown();
+
+        return r;
+}