#include <unistd.h>

#include <stddef.h>

#include <sys/epoll.h>

#include "systemd/sd-messages.h"

#include "socket-util.h"

#include "selinux-util.h"

#include "journald-server.h"

#include "journald-syslog.h"

#include "journald-kmsg.h"

#include "journald-console.h"

#include "journald-wall.h"

#define WARN_FORWARD_SYSLOG_MISSED_USEC (30 * USEC_PER_SEC)

static void forward_syslog_iovec(Server *s, const struct iovec *iovec, unsigned n_iovec, const struct ucred *ucred, const struct timeval *tv) {

static const union sockaddr_union sa = {

.un.sun_family = AF_UNIX,

.un.sun_path = "/run/systemd/journal/syslog",

};

struct msghdr msghdr = {

.msg_iov = (struct iovec *) iovec,

.msg_iovlen = n_iovec,

.msg_name = (struct sockaddr*) &sa.sa,

.msg_namelen = offsetof(union sockaddr_union, un.sun_path)

+ strlen("/run/systemd/journal/syslog"),

};

struct cmsghdr *cmsg;

union {

struct cmsghdr cmsghdr;

uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];

} control;

assert(s);

assert(iovec);

assert(n_iovec > 0);

if (ucred) {

zero(control);

msghdr.msg_control = &control;

msghdr.msg_controllen = sizeof(control);

cmsg = CMSG_FIRSTHDR(&msghdr);

cmsg->cmsg_level = SOL_SOCKET;

cmsg->cmsg_type = SCM_CREDENTIALS;

cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));

memcpy(CMSG_DATA(cmsg), ucred, sizeof(struct ucred));

msghdr.msg_controllen = cmsg->cmsg_len;

}

/* Forward the syslog message we received via /dev/log to

if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)

return;

/* The socket is full? I guess the syslog implementation is

if (errno == EAGAIN) {

s->n_forward_syslog_missed++;

return;

}

if (ucred && (errno == ESRCH || errno == EPERM)) {

struct ucred u;

/* Hmm, presumably the sender process vanished

u = *ucred;

u.pid = getpid();

memcpy(CMSG_DATA(cmsg), &u, sizeof(struct ucred));

if (sendmsg(s->syslog_fd, &msghdr, MSG_NOSIGNAL) >= 0)

return;

if (errno == EAGAIN) {

s->n_forward_syslog_missed++;

return;

}

}

if (errno != ENOENT)

log_debug_errno(errno, "Failed to forward syslog message: %m");

}

static void forward_syslog_raw(Server *s, int priority, const char *buffer, const struct ucred *ucred, const struct timeval *tv) {

struct iovec iovec;

assert(s);

assert(buffer);

if (LOG_PRI(priority) > s->max_level_syslog)

return;

IOVEC_SET_STRING(iovec, buffer);

forward_syslog_iovec(s, &iovec, 1, ucred, tv);

}

void server_forward_syslog(Server *s, int priority, const char *identifier, const char *message, const struct ucred *ucred, const struct timeval *tv) {

struct iovec iovec[5];

char header_priority[6], header_time[64], header_pid[16];

int n = 0;

time_t t;

struct tm *tm;

char *ident_buf = NULL;

assert(s);

assert(priority >= 0);

assert(priority <= 999);

assert(message);

if (LOG_PRI(priority) > s->max_level_syslog)

return;

/* First: priority field */

snprintf(header_priority, sizeof(header_priority), "<%i>", priority);

char_array_0(header_priority);

IOVEC_SET_STRING(iovec[n++], header_priority);

/* Second: timestamp */

t = tv ? tv->tv_sec : ((time_t) (now(CLOCK_REALTIME) / USEC_PER_SEC));

tm = localtime(&t);

if (!tm)

return;

if (strftime(header_time, sizeof(header_time), "%h %e %T ", tm) <= 0)

return;

IOVEC_SET_STRING(iovec[n++], header_time);

/* Third: identifier and PID */

if (ucred) {

if (!identifier) {

get_process_comm(ucred->pid, &ident_buf);

identifier = ident_buf;

}

snprintf(header_pid, sizeof(header_pid), "["PID_FMT"]: ", ucred->pid);

char_array_0(header_pid);

if (identifier)

IOVEC_SET_STRING(iovec[n++], identifier);

IOVEC_SET_STRING(iovec[n++], header_pid);

} else if (identifier) {

IOVEC_SET_STRING(iovec[n++], identifier);

IOVEC_SET_STRING(iovec[n++], ": ");

}

/* Fourth: message */

IOVEC_SET_STRING(iovec[n++], message);

forward_syslog_iovec(s, iovec, n, ucred, tv);

free(ident_buf);

}

int syslog_fixup_facility(int priority) {

if ((priority & LOG_FACMASK) == 0)

return (priority & LOG_PRIMASK) | LOG_USER;

return priority;

}

size_t syslog_parse_identifier(const char **buf, char **identifier, char **pid) {

const char *p;

char *t;

size_t l, e;

assert(buf);

assert(identifier);

assert(pid);

p = *buf;

p += strspn(p, WHITESPACE);

l = strcspn(p, WHITESPACE);

if (l <= 0 ||

p[l-1] != ':')

return 0;

e = l;

l--;

if (p[l-1] == ']') {

size_t k = l-1;

for (;;) {

if (p[k] == '[') {

t = strndup(p+k+1, l-k-2);

if (t)

*pid = t;

l = k;

break;

}

if (k == 0)

break;

k--;

}

}

t = strndup(p, l);

if (t)

*identifier = t;

e += strspn(p + e, WHITESPACE);

*buf = p + e;

return e;

}

static void syslog_skip_date(char **buf) {

enum {

LETTER,

SPACE,

NUMBER,

SPACE_OR_NUMBER,

COLON

} sequence[] = {

LETTER, LETTER, LETTER,

SPACE,

SPACE_OR_NUMBER, NUMBER,

SPACE,

SPACE_OR_NUMBER, NUMBER,

COLON,

SPACE_OR_NUMBER, NUMBER,

COLON,

SPACE_OR_NUMBER, NUMBER,

SPACE

};

char *p;

unsigned i;

assert(buf);

assert(*buf);

p = *buf;

for (i = 0; i < ELEMENTSOF(sequence); i++, p++) {

if (!*p)

return;

switch (sequence[i]) {

case SPACE:

if (*p != ' ')

return;

break;

case SPACE_OR_NUMBER:

if (*p == ' ')

break;

/* fall through */

case NUMBER:

if (*p < '0' || *p > '9')

return;

break;

case LETTER:

if (!(*p >= 'A' && *p <= 'Z') &&

!(*p >= 'a' && *p <= 'z'))

return;

break;

case COLON:

if (*p != ':')

return;

break;

}

}

*buf = p;

}

void server_process_syslog_message(

Server *s,

const char *buf,

const struct ucred *ucred,

const struct timeval *tv,

const char *label,

size_t label_len) {

char syslog_priority[sizeof("PRIORITY=") + DECIMAL_STR_MAX(int)],

syslog_facility[sizeof("SYSLOG_FACILITY") + DECIMAL_STR_MAX(int)];

const char *message = NULL, *syslog_identifier = NULL, *syslog_pid = NULL;

struct iovec iovec[N_IOVEC_META_FIELDS + 6];

unsigned n = 0;

int priority = LOG_USER | LOG_INFO;

_cleanup_free_ char *identifier = NULL, *pid = NULL;

const char *orig;

assert(s);

assert(buf);

orig = buf;

syslog_parse_priority(&buf, &priority, true);

if (s->forward_to_syslog)

forward_syslog_raw(s, priority, orig, ucred, tv);

syslog_skip_date((char**) &buf);

syslog_parse_identifier(&buf, &identifier, &pid);

if (s->forward_to_kmsg)

server_forward_kmsg(s, priority, identifier, buf, ucred);

if (s->forward_to_console)

server_forward_console(s, priority, identifier, buf, ucred);

if (s->forward_to_wall)

server_forward_wall(s, priority, identifier, buf, ucred);

IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=syslog");

sprintf(syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK);

IOVEC_SET_STRING(iovec[n++], syslog_priority);

if (priority & LOG_FACMASK) {

sprintf(syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority));

IOVEC_SET_STRING(iovec[n++], syslog_facility);

}

if (identifier) {

syslog_identifier = strappenda("SYSLOG_IDENTIFIER=", identifier);

if (syslog_identifier)

IOVEC_SET_STRING(iovec[n++], syslog_identifier);

}

if (pid) {

syslog_pid = strappenda("SYSLOG_PID=", pid);

if (syslog_pid)

IOVEC_SET_STRING(iovec[n++], syslog_pid);

}

message = strappenda("MESSAGE=", buf);

if (message)

IOVEC_SET_STRING(iovec[n++], message);

server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), ucred, tv, label, label_len, NULL, priority, 0);

}

int server_open_syslog_socket(Server *s) {

static const int one = 1;

int r;

assert(s);

if (s->syslog_fd < 0) {

static const union sockaddr_union sa = {

.un.sun_family = AF_UNIX,

.un.sun_path = "/run/systemd/journal/dev-log",

};

s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (s->syslog_fd < 0)

return log_error_errno(errno, "socket() failed: %m");

unlink(sa.un.sun_path);

r = bind(s->syslog_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));

if (r < 0)

return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);

chmod(sa.un.sun_path, 0666);

} else

fd_nonblock(s->syslog_fd, 1);

r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));

if (r < 0)

return log_error_errno(errno, "SO_PASSCRED failed: %m");

#ifdef HAVE_SELINUX

if (mac_selinux_use()) {

r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one));

if (r < 0)

log_warning_errno(errno, "SO_PASSSEC failed: %m");

}

#endif

r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));

if (r < 0)

return log_error_errno(errno, "SO_TIMESTAMP failed: %m");

r = sd_event_add_io(s->event, &s->syslog_event_source, s->syslog_fd, EPOLLIN, server_process_datagram, s);

if (r < 0)

return log_error_errno(r, "Failed to add syslog server fd to event loop: %m");

return 0;

}

void server_maybe_warn_forward_syslog_missed(Server *s) {

usec_t n;

assert(s);

if (s->n_forward_syslog_missed <= 0)

return;

n = now(CLOCK_MONOTONIC);

if (s->last_warn_forward_syslog_missed + WARN_FORWARD_SYSLOG_MISSED_USEC > n)

return;

server_driver_message(s, SD_MESSAGE_FORWARD_SYSLOG_MISSED, "Forwarding to syslog missed %u messages.", s->n_forward_syslog_missed);

s->n_forward_syslog_missed = 0;

s->last_warn_forward_syslog_missed = n;

}