#include <sys/epoll.h>

#include <sys/socket.h>

#include <errno.h>

#include <sys/signalfd.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/acl.h>

#include <acl/libacl.h>

#include "hashmap.h"

#include "journal-file.h"

#include "sd-daemon.h"

#include "socket-util.h"

#include "acl-util.h"

#include "cgroup-util.h"

typedef struct Server {

int syslog_fd;

int epoll_fd;

int signal_fd;

JournalFile *runtime_journal;

JournalFile *system_journal;

Hashmap *user_journals;

uint64_t seqnum;

} Server;

static void fix_perms(JournalFile *f, uid_t uid) {

acl_t acl;

acl_entry_t entry;

acl_permset_t permset;

int r;

assert(f);

r = fchmod_and_fchown(f->fd, 0640, 0, 0);

if (r < 0)

log_warning("Failed to fix access mode/rights on %s, ignoring: %s", f->path, strerror(-r));

if (uid <= 0)

return;

acl = acl_get_fd(f->fd);

if (!acl) {

log_warning("Failed to read ACL on %s, ignoring: %m", f->path);

return;

}

r = acl_find_uid(acl, uid, &entry);

if (r <= 0) {

if (acl_create_entry(&acl, &entry) < 0 ||

acl_set_tag_type(entry, ACL_USER) < 0 ||

acl_set_qualifier(entry, &uid) < 0) {

log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);

goto finish;

}

}

if (acl_get_permset(entry, &permset) < 0 ||

acl_add_perm(permset, ACL_READ) < 0 ||

acl_calc_mask(&acl) < 0) {

log_warning("Failed to patch ACL on %s, ignoring: %m", f->path);

goto finish;

}

if (acl_set_fd(f->fd, acl) < 0)

log_warning("Failed to set ACL on %s, ignoring: %m", f->path);

finish:

acl_free(acl);

}

static JournalFile* find_journal(Server *s, uid_t uid) {

char *p;

int r;

JournalFile *f;

char ids[33];

sd_id128_t machine;

assert(s);

/* We split up user logs only on /var, not on /run */

if (!s->system_journal)

return s->runtime_journal;

if (uid <= 0)

return s->system_journal;

r = sd_id128_get_machine(&machine);

if (r < 0)

return s->system_journal;

f = hashmap_get(s->user_journals, UINT32_TO_PTR(uid));

if (f)

return f;

if (asprintf(&p, "/var/log/journal/%s/user-%lu.journal", sd_id128_to_string(machine, ids), (unsigned long) uid) < 0)

return s->system_journal;

r = journal_file_open(p, O_RDWR|O_CREAT, 0640, s->system_journal, &f);

free(p);

if (r < 0)

return s->system_journal;

fix_perms(f, uid);

r = hashmap_put(s->user_journals, UINT32_TO_PTR(uid), f);

if (r < 0) {

journal_file_close(f);

return s->system_journal;

}

return f;

}

static void process_message(Server *s, const char *buf, struct ucred *ucred, struct timeval *tv) {

char *message = NULL, *pid = NULL, *uid = NULL, *gid = NULL,

*source_time = NULL, *boot_id = NULL, *machine_id = NULL,

*comm = NULL, *cmdline = NULL, *hostname = NULL,

*audit_session = NULL, *audit_loginuid = NULL,

*syslog_priority = NULL, *syslog_facility = NULL,

*exe = NULL, *cgroup = NULL;

struct iovec iovec[17];

unsigned n = 0;

char idbuf[33];

sd_id128_t id;

int r;

char *t;

int priority = LOG_USER | LOG_INFO;

uid_t loginuid = 0, realuid = 0;

JournalFile *f;

parse_syslog_priority((char**) &buf, &priority);

skip_syslog_date((char**) &buf);

if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)

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

if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)

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

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

if (message)

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

if (ucred) {

uint32_t session;

char *path;

realuid = ucred->uid;

if (asprintf(&pid, "_PID=%lu", (unsigned long) ucred->pid) >= 0)

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

if (asprintf(&uid, "_UID=%lu", (unsigned long) ucred->uid) >= 0)

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

if (asprintf(&gid, "_GID=%lu", (unsigned long) ucred->gid) >= 0)

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

r = get_process_comm(ucred->pid, &t);

if (r >= 0) {

comm = strappend("_COMM=", t);

if (comm)

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

free(t);

}

r = get_process_exe(ucred->pid, &t);

if (r >= 0) {

exe = strappend("_EXE=", t);

if (comm)

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

free(t);

}

r = get_process_cmdline(ucred->pid, LINE_MAX, false, &t);

if (r >= 0) {

cmdline = strappend("_CMDLINE=", t);

if (cmdline)

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

free(t);

}

r = audit_session_from_pid(ucred->pid, &session);

if (r >= 0)

if (asprintf(&audit_session, "_AUDIT_SESSION=%lu", (unsigned long) session) >= 0)

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

r = audit_loginuid_from_pid(ucred->pid, &loginuid);

if (r >= 0)

if (asprintf(&audit_loginuid, "_AUDIT_LOGINUID=%lu", (unsigned long) loginuid) >= 0)

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

r = cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, ucred->pid, &path);

if (r >= 0) {

cgroup = strappend("_SYSTEMD_CGROUP=", path);

if (cgroup)

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

free(path);

}

}

if (tv) {

if (asprintf(&source_time, "_SOURCE_REALTIME_TIMESTAMP=%llu",

(unsigned long long) timeval_load(tv)) >= 0)

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

}

/* Note that strictly speaking storing the boot id here is

r = sd_id128_get_boot(&id);

if (r >= 0)

if (asprintf(&boot_id, "_BOOT_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)

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

r = sd_id128_get_machine(&id);

if (r >= 0)

if (asprintf(&machine_id, "_MACHINE_ID=%s", sd_id128_to_string(id, idbuf)) >= 0)

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

t = gethostname_malloc();

if (t) {

hostname = strappend("_HOSTNAME=", t);

if (hostname)

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

free(t);

}

f = find_journal(s, realuid == 0 ? 0 : loginuid);

if (!f)

log_warning("Dropping message, as we can't find a place to store the data.");

else {

r = journal_file_append_entry(f, NULL, iovec, n, &s->seqnum, NULL, NULL);

if (r < 0)

log_error("Failed to write entry, ignoring: %s", strerror(-r));

}

free(message);

free(pid);

free(uid);

free(gid);

free(comm);

free(exe);

free(cmdline);

free(source_time);

free(boot_id);

free(machine_id);

free(hostname);

free(audit_session);

free(audit_loginuid);

free(syslog_facility);

free(syslog_priority);

free(cgroup);

}

static int process_event(Server *s, struct epoll_event *ev) {

assert(s);

if (ev->events != EPOLLIN) {

log_info("Got invalid event from epoll.");

return -EIO;

}

if (ev->data.fd == s->signal_fd) {

struct signalfd_siginfo sfsi;

ssize_t n;

n = read(s->signal_fd, &sfsi, sizeof(sfsi));

if (n != sizeof(sfsi)) {

if (n >= 0)

return -EIO;

if (errno == EINTR || errno == EAGAIN)

return 0;

return -errno;

}

log_debug("Received SIG%s", signal_to_string(sfsi.ssi_signo));

return 0;

}

if (ev->data.fd == s->syslog_fd) {

for (;;) {

char buf[LINE_MAX+1];

struct msghdr msghdr;

struct iovec iovec;

struct ucred *ucred = NULL;

struct timeval *tv = NULL;

struct cmsghdr *cmsg;

union {

struct cmsghdr cmsghdr;

uint8_t buf[CMSG_SPACE(sizeof(struct ucred)) +

CMSG_SPACE(sizeof(struct timeval))];

} control;

ssize_t n;

char *e;

zero(iovec);

iovec.iov_base = buf;

iovec.iov_len = sizeof(buf)-1;

zero(control);

zero(msghdr);

msghdr.msg_iov = &iovec;

msghdr.msg_iovlen = 1;

msghdr.msg_control = &control;

msghdr.msg_controllen = sizeof(control);

n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT);

if (n < 0) {

if (errno == EINTR || errno == EAGAIN)

return 1;

log_error("recvmsg() failed: %m");

return -errno;

}

for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {

if (cmsg->cmsg_level == SOL_SOCKET &&

cmsg->cmsg_type == SCM_CREDENTIALS &&

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

ucred = (struct ucred*) CMSG_DATA(cmsg);

else if (cmsg->cmsg_level == SOL_SOCKET &&

cmsg->cmsg_type == SO_TIMESTAMP &&

cmsg->cmsg_len == CMSG_LEN(sizeof(struct timeval)))

tv = (struct timeval*) CMSG_DATA(cmsg);

}

e = memchr(buf, '\n', n);

if (e)

*e = 0;

else

buf[n] = 0;

process_message(s, strstrip(buf), ucred, tv);

}

return 1;

}

log_error("Unknown event.");

return 0;

}

static int system_journal_open(Server *s) {

int r;

char *fn;

sd_id128_t machine;

char ids[33];

r = sd_id128_get_machine(&machine);

if (r < 0)

return r;

/* First try to create the machine path, but not the prefix */

fn = strappend("/var/log/journal/", sd_id128_to_string(machine, ids));

if (!fn)

return -ENOMEM;

(void) mkdir(fn, 0755);

free(fn);

/* The create the system journal file */

fn = join("/var/log/journal/", ids, "/system.journal", NULL);

if (!fn)

return -ENOMEM;

r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->system_journal);

free(fn);

if (r >= 0) {

fix_perms(s->system_journal, 0);

return r;

}

if (r < 0 && r != -ENOENT) {

log_error("Failed to open system journal: %s", strerror(-r));

return r;

}

/* /var didn't work, so try /run, but this time we

fn = join("/run/log/journal/", ids, "/system.journal", NULL);

if (!fn)

return -ENOMEM;

(void) mkdir_parents(fn, 0755);

r = journal_file_open(fn, O_RDWR|O_CREAT, 0640, NULL, &s->runtime_journal);

free(fn);

if (r < 0) {

log_error("Failed to open runtime journal: %s", strerror(-r));

return r;

}

fix_perms(s->runtime_journal, 0);

return r;

}

static int server_init(Server *s) {

int n, one, r;

struct epoll_event ev;

sigset_t mask;

assert(s);

zero(*s);

s->syslog_fd = s->signal_fd = -1;

s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);

if (s->epoll_fd < 0) {

log_error("Failed to create epoll object: %m");

return -errno;

}

n = sd_listen_fds(true);

if (n < 0) {

log_error("Failed to read listening file descriptors from environment: %s", strerror(-n));

return n;

}

if (n > 1) {

log_error("Too many file descriptors passed.");

return -EINVAL;

}

if (n == 1)

s->syslog_fd = SD_LISTEN_FDS_START;

else {

union sockaddr_union sa;

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

if (s->syslog_fd < 0) {

log_error("socket() failed: %m");

return -errno;

}

zero(sa);

sa.un.sun_family = AF_UNIX;

strncpy(sa.un.sun_path, "/run/systemd/syslog", sizeof(sa.un.sun_path));

unlink(sa.un.sun_path);

r = bind(s->syslog_fd, &sa.sa, sizeof(sa.un));

if (r < 0) {

log_error("bind() failed: %m");

return -errno;

}

chmod(sa.un.sun_path, 0666);

}

one = 1;

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

if (r < 0) {

log_error("SO_PASSCRED failed: %m");

return -errno;

}

one = 1;

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

if (r < 0) {

log_error("SO_TIMESTAMP failed: %m");

return -errno;

}

zero(ev);

ev.events = EPOLLIN;

ev.data.fd = s->syslog_fd;

if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->syslog_fd, &ev) < 0) {

log_error("Failed to add server fd to epoll object: %m");

return -errno;

}

s->user_journals = hashmap_new(trivial_hash_func, trivial_compare_func);

if (!s->user_journals) {

log_error("Out of memory.");

return -ENOMEM;

}

r = system_journal_open(s);

if (r < 0)

return r;

assert_se(sigemptyset(&mask) == 0);

sigset_add_many(&mask, SIGINT, SIGTERM, -1);

assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);

s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);

if (s->signal_fd < 0) {

log_error("signalfd(): %m");

return -errno;

}

zero(ev);

ev.events = EPOLLIN;

ev.data.fd = s->signal_fd;

if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {

log_error("epoll_ctl(): %m");

return -errno;

}

return 0;

}

static void server_done(Server *s) {

JournalFile *f;

assert(s);

if (s->system_journal)

journal_file_close(s->system_journal);

if (s->runtime_journal)

journal_file_close(s->runtime_journal);

while ((f = hashmap_steal_first(s->user_journals)))

journal_file_close(f);

hashmap_free(s->user_journals);

if (s->epoll_fd >= 0)

close_nointr_nofail(s->epoll_fd);

if (s->signal_fd >= 0)

close_nointr_nofail(s->signal_fd);

if (s->syslog_fd >= 0)

close_nointr_nofail(s->syslog_fd);

}

int main(int argc, char *argv[]) {

Server server;

int r;

/* 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_set_target(LOG_TARGET_CONSOLE);

log_parse_environment();

log_open();

umask(0022);

r = server_init(&server);

if (r < 0)

goto finish;

log_debug("systemd-journald running as pid %lu", (unsigned long) getpid());

sd_notify(false,

"READY=1\n"

"STATUS=Processing messages...");

#

for (;;) {

struct epoll_event event;

r = epoll_wait(server.epoll_fd, &event, 1, -1);

if (r < 0) {

if (errno == EINTR)

continue;

log_error("epoll_wait() failed: %m");

r = -errno;

goto finish;

} else if (r == 0)

break;

r = process_event(&server, &event);

if (r < 0)

goto finish;

else if (r == 0)

break;

}

finish:

sd_notify(false,

"STATUS=Shutting down...");

server_done(&server);

return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;

}