+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+#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 "util.h"
+#include "log.h"
+#include "list.h"
+
+#define STREAM_BUFFER 2048
+#define STREAMS_MAX 256
+#define SERVER_FD_START 3
+#define SERVER_FD_MAX 16
+#define TIMEOUT ((int) (10*MSEC_PER_SEC))
+
+typedef struct Stream Stream;
+
+typedef struct Server {
+ int log_fd;
+ int epoll_fd;
+
+ unsigned n_server_fd;
+
+ LIST_HEAD(Stream, streams);
+ unsigned n_streams;
+} Server;
+
+typedef enum StreamState {
+ STREAM_PRIORITY,
+ STREAM_PROCESS,
+ STREAM_RUNNING
+} StreamState;
+
+struct Stream {
+ Server *server;
+
+ StreamState state;
+
+ int fd;
+ int priority;
+ char *process;
+
+ char buffer[STREAM_BUFFER];
+ size_t length;
+
+ pid_t pid;
+
+ LIST_FIELDS(Stream, stream);
+};
+
+#define IOVEC_SET_STRING(iovec, s) \
+ do { \
+ (iovec).iov_base = s; \
+ (iovec).iov_len = strlen(s); \
+ } while(false);
+
+static int stream_log(Stream *s, char *p, usec_t timestamp) {
+
+ char header_priority[16], header_time[64], header_pid[16];
+ time_t t;
+ struct tm *tm;
+ struct msghdr msghdr;
+ struct iovec iovec[5];
+
+ assert(s);
+ assert(p);
+
+ if (*p == 0)
+ return 0;
+
+ /*
+ * The format glibc uses is:
+ *
+ * <priority>time process[pid]: msg
+ */
+
+ snprintf(header_priority, sizeof(header_priority), "<%i>", s->priority);
+ char_array_0(header_priority);
+
+ t = (time_t) (timestamp / USEC_PER_SEC);
+ if (!(tm = localtime(&t)))
+ return -EINVAL;
+
+ if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)
+ return -EINVAL;
+
+ snprintf(header_pid, sizeof(header_pid), "[%llu]: ", (unsigned long long) s->pid);
+ char_array_0(header_pid);
+
+ zero(iovec);
+ IOVEC_SET_STRING(iovec[0], header_priority);
+ IOVEC_SET_STRING(iovec[1], header_time);
+ IOVEC_SET_STRING(iovec[2], s->process);
+ IOVEC_SET_STRING(iovec[3], header_pid);
+ IOVEC_SET_STRING(iovec[4], p);
+
+ zero(msghdr);
+ msghdr.msg_iov = iovec;
+ msghdr.msg_iovlen = ELEMENTSOF(iovec);
+
+ if (sendmsg(s->server->log_fd, &msghdr, MSG_NOSIGNAL) < 0)
+ return -errno;
+
+ return 0;
+}
+
+static int stream_line(Stream *s, char *p, usec_t timestamp) {
+ int r;
+
+ assert(s);
+ assert(p);
+
+ p = strstrip(p);
+
+ switch (s->state) {
+
+ case STREAM_PRIORITY:
+ if ((r = safe_atoi(p, &s->priority)) < 0)
+ return r;
+
+ if (s->priority < 0)
+ return -ERANGE;
+
+ s->state = STREAM_PROCESS;
+ return 0;
+
+ case STREAM_PROCESS:
+ if (!(s->process = strdup(p)))
+ return -ENOMEM;
+
+ s->state = STREAM_RUNNING;
+ return 0;
+
+ case STREAM_RUNNING:
+ return stream_log(s, p, timestamp);
+ }
+
+ assert_not_reached("Unknown stream state");
+}
+
+static int stream_scan(Stream *s, usec_t timestamp) {
+ char *p;
+ size_t remaining;
+ int r = 0;
+
+ assert(s);
+
+ p = s->buffer;
+ remaining = s->length;
+ for (;;) {
+ char *newline;
+
+ if (!(newline = memchr(p, '\n', remaining)))
+ break;
+
+ *newline = 0;
+
+ if ((r = stream_line(s, p, timestamp)) >= 0) {
+ remaining -= newline-p+1;
+ p = newline+1;
+ }
+ }
+
+ if (p > s->buffer) {
+ memmove(s->buffer, p, remaining);
+ s->length = remaining;
+ }
+
+ return r;
+}
+
+static int stream_process(Stream *s, usec_t timestamp) {
+ ssize_t l;
+ int r;
+ assert(s);
+
+ if ((l = read(s->fd, s->buffer+s->length, STREAM_BUFFER-s->length)) < 0) {
+
+ if (errno == EAGAIN)
+ return 0;
+
+ log_warning("Failed to read from stream: %s", strerror(errno));
+ return -1;
+ }
+
+
+ if (l == 0)
+ return 0;
+
+ s->length += l;
+ r = stream_scan(s, timestamp);
+
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static void stream_free(Stream *s) {
+ assert(s);
+
+ if (s->server) {
+ assert(s->server->n_streams > 0);
+ s->server->n_streams--;
+ LIST_REMOVE(Stream, stream, s->server->streams, s);
+
+ }
+
+ if (s->fd >= 0) {
+ if (s->server)
+ epoll_ctl(s->server->epoll_fd, EPOLL_CTL_DEL, s->fd, NULL);
+
+ assert_se(close_nointr(s->fd) == 0);
+ }
+
+ free(s->process);
+ free(s);
+}
+
+static int stream_new(Server *s, int server_fd) {
+ Stream *stream;
+ int fd;
+ struct ucred ucred;
+ socklen_t len = sizeof(ucred);
+ struct epoll_event ev;
+ int r;
+
+ assert(s);
+
+ if ((fd = accept4(server_fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC)) < 0)
+ return -errno;
+
+ if (s->n_streams >= STREAMS_MAX) {
+ log_warning("Too many connections, refusing connection.");
+ assert_se(close_nointr(fd) == 0);
+ return 0;
+ }
+
+ if (!(stream = new0(Stream, 1))) {
+ assert_se(close_nointr(fd) == 0);
+ return -ENOMEM;
+ }
+
+ stream->fd = fd;
+
+ if (getsockopt(stream->fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
+ r = -errno;
+ goto fail;
+ }
+
+ if (shutdown(fd, SHUT_WR) < 0) {
+ r = -errno;
+ goto fail;
+ }
+
+ zero(ev);
+ ev.data.ptr = stream;
+ ev.events = POLLIN;
+ if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
+ r = -errno;
+ goto fail;
+ }
+
+ stream->pid = ucred.pid;
+
+ stream->server = s;
+ LIST_PREPEND(Stream, stream, s->streams, stream);
+ s->n_streams ++;
+
+ return 0;
+
+fail:
+ stream_free(stream);
+ return r;
+}
+
+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) {
+ unsigned i;
+ assert(s);
+
+ while (s->streams)
+ stream_free(s->streams);
+
+ for (i = 0; i < s->n_server_fd; i++)
+ assert_se(close_nointr(SERVER_FD_START+i) == 0);
+
+ if (s->log_fd >= 0)
+ assert_se(close_nointr(s->log_fd) == 0);
+
+ if (s->epoll_fd >= 0)
+ assert_se(close_nointr(s->epoll_fd) == 0);
+}
+
+static int server_init(Server *s, unsigned n_sockets) {
+ int r;
+ unsigned i;
+ union {
+ struct sockaddr sa;
+ struct sockaddr_un un;
+ } sa;
+
+ assert(s);
+ assert(n_sockets > 0);
+
+ zero(*s);
+
+ s->n_server_fd = n_sockets;
+ s->log_fd = -1;
+
+ 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;
+
+ zero(ev);
+ ev.events = POLLIN;
+ ev.data.ptr = UINT_TO_PTR(SERVER_FD_START+i);
+ if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, SERVER_FD_START+i, &ev) < 0) {
+ r = -errno;
+ log_error("Failed to add server fd to epoll object: %s", strerror(errno));
+ goto fail;
+ }
+ }
+
+ if ((s->log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) {
+ r = -errno;
+ log_error("Failed to create log fd: %s", strerror(errno));
+ goto fail;
+ }
+
+ zero(sa);
+ sa.un.sun_family = AF_UNIX;
+ strncpy(sa.un.sun_path, "/dev/log", sizeof(sa.un.sun_path));
+
+ if (connect(s->log_fd, &sa.sa, sizeof(sa)) < 0) {
+ r = -errno;
+ log_error("Failed to connect log socket to /dev/log: %s", strerror(errno));
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ server_done(s);
+ return r;
+}
+
+static int process_event(Server *s, struct epoll_event *ev) {
+ int r;
+
+ assert(s);
+
+ /* Yes, this is a bit ugly, we assume that that valid pointers
+ * are > SERVER_FD_START+SERVER_FD_MAX. Which is certainly
+ * true on Linux (and probably most other OSes, too, since the
+ * first 4k usually are part of a seperate null pointer
+ * dereference page. */
+
+ if (PTR_TO_UINT(ev->data.ptr) >= SERVER_FD_START &&
+ PTR_TO_UINT(ev->data.ptr) < SERVER_FD_START+s->n_server_fd) {
+
+ if (ev->events != POLLIN) {
+ log_info("Got invalid event from epoll. (1)");
+ return -EIO;
+ }
+
+ if ((r = stream_new(s, PTR_TO_UINT(ev->data.ptr))) < 0) {
+ log_info("Failed to accept new connection: %s", strerror(-r));
+ return r;
+ }
+
+ } else {
+ usec_t timestamp;
+ Stream *stream = ev->data.ptr;
+
+ timestamp = now(CLOCK_REALTIME);
+
+ if (!(ev->events & POLLIN)) {
+ log_info("Got invalid event from epoll. (3)");
+ stream_free(stream);
+ return 0;
+ }
+
+ if ((r = stream_process(stream, timestamp)) <= 0) {
+
+ if (r < 0)
+ log_info("Got error on stream: %s", strerror(-r));
+
+ stream_free(stream);
+ return 0;
+ }
+ }
+
+ return 0;
+}
+
+int main(int argc, char *argv[]) {
+ Server server;
+ int r = 3;
+ unsigned n;
+
+ log_info("systemd-logger 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 n;
+
+ if ((n = epoll_wait(server.epoll_fd,
+ &event, 1,
+ server.n_streams <= 0 ? TIMEOUT : -1)) < 0) {
+
+ if (errno == EINTR)
+ continue;
+
+ log_error("epoll_wait() failed: %s", strerror(errno));
+ goto fail;
+ }
+
+ if (n <= 0)
+ break;
+
+ if ((r = process_event(&server, &event)) < 0)
+ goto fail;
+ }
+ r = 0;
+
+fail:
+ server_done(&server);
+
+ log_info("systemd-logger stopped as pid %llu", (unsigned long long) getpid());
+
+ return r;
+}
~ianmdlvl / elogind.git / commitdiff