#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;

/*

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

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;

}