morgan/systemd
1
0
Fork 0
mirror of https://github.com/morgan9e/systemd synced 2026-04-15 00:47:10 +09:00
Code Issues Packages Projects Releases Wiki Activity
Files
df5b3426f60bb626f46f93fbdacecae274c1645b
systemd/src/journal/journald-native.c

512 lines
20 KiB
C
Raw Blame History

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <sys/statvfs.h>
#include <unistd.h>
#include "sd-event.h"
#include "alloc-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "format-util.h"
#include "iovec-util.h"
#include "journal-importer.h"
#include "journal-internal.h"
#include "journald-client.h"
#include "journald-console.h"
#include "journald-context.h"
#include "journald-kmsg.h"
#include "journald-manager.h"
#include "journald-native.h"
#include "journald-syslog.h"
#include "journald-wall.h"
#include "log.h"
#include "log-ratelimit.h"
#include "memfd-util.h"
#include "memory-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "process-util.h"
#include "selinux-util.h"
#include "socket-util.h"
#include "stat-util.h"
#include "string-util.h"
#include "unaligned.h"
static bool allow_object_pid(const struct ucred *ucred) {
return ucred && ucred->uid == 0;
}
static void manager_process_entry_meta(
const char *p, size_t l,
const struct ucred *ucred,
int *priority,
char **identifier,
char **message,
pid_t *object_pid) {
/* We need to determine the priority of this entry for the rate limiting logic */
if (l == 10 &&
startswith(p, "PRIORITY=") &&
p[9] >= '0' && p[9] <= '9')
*priority = (*priority & LOG_FACMASK) | (p[9] - '0');
else if (l == 17 &&
startswith(p, "SYSLOG_FACILITY=") &&
p[16] >= '0' && p[16] <= '9')
*priority = LOG_PRI(*priority) | ((p[16] - '0') << 3);
else if (l == 18 &&
startswith(p, "SYSLOG_FACILITY=") &&
p[16] >= '0' && p[16] <= '9' &&
p[17] >= '0' && p[17] <= '9')
*priority = LOG_PRI(*priority) | (((p[16] - '0')*10 + (p[17] - '0')) << 3);
else if (l >= 19 &&
startswith(p, "SYSLOG_IDENTIFIER=")) {
char *t;
t = memdup_suffix0(p + 18, l - 18);
if (t)
free_and_replace(*identifier, t);
} else if (l >= 8 &&
startswith(p, "MESSAGE=")) {
char *t;
t = memdup_suffix0(p + 8, l - 8);
if (t)
free_and_replace(*message, t);
} else if (l > STRLEN("OBJECT_PID=") &&
l < STRLEN("OBJECT_PID=") + DECIMAL_STR_MAX(pid_t) &&
startswith(p, "OBJECT_PID=") &&
allow_object_pid(ucred)) {
char buf[DECIMAL_STR_MAX(pid_t)];
memcpy(buf, p + STRLEN("OBJECT_PID="),
l - STRLEN("OBJECT_PID="));
buf[l-STRLEN("OBJECT_PID=")] = '\0';
(void) parse_pid(buf, object_pid);
}
}
static int manager_process_entry(
Manager *m,
const void *buffer, size_t *remaining,
ClientContext *context,
const struct ucred *ucred,
const struct timeval *tv,
const char *label, size_t label_len) {
/* Process a single entry from a native message. Returns 0 if nothing special happened and the message
* processing should continue, and a negative or positive value otherwise.
*
* Note that *remaining is altered on both success and failure. */
size_t n = 0, j, tn = SIZE_MAX, entry_size = 0;
char *identifier = NULL, *message = NULL;
struct iovec *iovec = NULL;
int priority = LOG_INFO;
pid_t object_pid = 0;
const char *p;
int r = 1;
p = buffer;
while (*remaining > 0) {
const char *e, *q;
e = memchr(p, '\n', *remaining);
if (!e) {
/* Trailing noise, let's ignore it, and flush what we collected */
log_debug("Received message with trailing noise, ignoring.");
break; /* finish processing of the message */
}
if (e == p) {
/* Entry separator */
*remaining -= 1;
break;
}
if (IN_SET(*p, '.', '#')) {
/* Ignore control commands for now, and comments too. */
*remaining -= (e - p) + 1;
p = e + 1;
continue;
}
/* A property follows */
if (n > ENTRY_FIELD_COUNT_MAX) {
log_debug("Received an entry that has more than " STRINGIFY(ENTRY_FIELD_COUNT_MAX) " fields, ignoring entry.");
goto finish;
}
/* n existing properties, 1 new, +1 for _TRANSPORT */
if (!GREEDY_REALLOC(iovec,
n + 2 +
N_IOVEC_META_FIELDS + N_IOVEC_OBJECT_FIELDS +
client_context_extra_fields_n_iovec(context))) {
r = log_oom();
goto finish;
}
q = memchr(p, '=', e - p);
if (q) {
if (journal_field_valid(p, q - p, false)) {
size_t l;
l = e - p;
if (l > DATA_SIZE_MAX) {
log_debug("Received text block of %zu bytes is too large, ignoring entry.", l);
goto finish;
}
if (entry_size + l + n + 1 > ENTRY_SIZE_MAX) { /* data + separators + trailer */
log_debug("Entry is too big (%zu bytes after processing %zu entries), ignoring entry.",
entry_size + l, n + 1);
goto finish;
}
/* If the field name starts with an underscore, skip the variable, since that indicates
* a trusted field */
iovec[n++] = IOVEC_MAKE((char*) p, l);
entry_size += l;
manager_process_entry_meta(p, l, ucred,
&priority,
&identifier,
&message,
&object_pid);
}
*remaining -= (e - p) + 1;
p = e + 1;
continue;
} else {
uint64_t l, total;
char *k;
if (*remaining < e - p + 1 + sizeof(uint64_t) + 1) {
log_debug("Failed to parse message, ignoring.");
break;
}
l = unaligned_read_le64(e + 1);
if (l > DATA_SIZE_MAX) {
log_debug("Received binary data block of %"PRIu64" bytes is too large, ignoring entry.", l);
goto finish;
}
total = (e - p) + 1 + l;
if (entry_size + total + n + 1 > ENTRY_SIZE_MAX) { /* data + separators + trailer */
log_debug("Entry is too big (%"PRIu64"bytes after processing %zu fields), ignoring.",
entry_size + total, n + 1);
goto finish;
}
if ((uint64_t) *remaining < e - p + 1 + sizeof(uint64_t) + l + 1 ||
e[1+sizeof(uint64_t)+l] != '\n') {
log_debug("Failed to parse message, ignoring.");
break;
}
k = malloc(total);
if (!k) {
log_oom();
break;
}
memcpy(k, p, e - p);
k[e - p] = '=';
memcpy(k + (e - p) + 1, e + 1 + sizeof(uint64_t), l);
if (journal_field_valid(p, e - p, false)) {
iovec[n] = IOVEC_MAKE(k, (e - p) + 1 + l);
entry_size += iovec[n].iov_len;
n++;
manager_process_entry_meta(k, (e - p) + 1 + l, ucred,
&priority,
&identifier,
&message,
&object_pid);
} else
free(k);
*remaining -= (e - p) + 1 + sizeof(uint64_t) + l + 1;
p = e + 1 + sizeof(uint64_t) + l + 1;
}
}
if (n <= 0)
goto finish;
tn = n++;
iovec[tn] = IOVEC_MAKE_STRING("_TRANSPORT=journal");
entry_size += STRLEN("_TRANSPORT=journal");
if (entry_size + n + 1 > ENTRY_SIZE_MAX) { /* data + separators + trailer */
log_debug("Entry is too big with %zu properties and %zu bytes, ignoring.", n, entry_size);
goto finish;
}
r = 0; /* Success, we read the message. */
if (!client_context_test_priority(context, priority))
goto finish;
if (message) {
/* Ensure message is not NULL, otherwise strlen(message) would crash. This check needs to
* be here until manager_process_entry() is able to process messages containing \0 characters,
* as we would have access to the actual size of message. */
r = client_context_check_keep_log(context, message, strlen(message));
if (r <= 0)
goto finish;
if (m->config.forward_to_syslog)
manager_forward_syslog(m, syslog_fixup_facility(priority), identifier, message, ucred, tv);
if (m->config.forward_to_kmsg)
manager_forward_kmsg(m, priority, identifier, message, ucred);
if (m->config.forward_to_console)
manager_forward_console(m, priority, identifier, message, ucred);
if (m->config.forward_to_wall)
manager_forward_wall(m, priority, identifier, message, ucred);
}
manager_dispatch_message(m, iovec, n, MALLOC_ELEMENTSOF(iovec), context, tv, priority, object_pid);
finish:
for (j = 0; j < n; j++) {
if (j == tn)
continue;
if (iovec[j].iov_base < buffer ||
(const char*) iovec[j].iov_base >= p + *remaining)
free(iovec[j].iov_base);
}
free(iovec);
free(identifier);
free(message);
return r;
}
void manager_process_native_message(
Manager *m,
const char *buffer, size_t buffer_size,
const struct ucred *ucred,
const struct timeval *tv,
const char *label, size_t label_len) {
size_t remaining = buffer_size;
ClientContext *context = NULL;
int r;
assert(m);
assert(buffer || buffer_size == 0);
if (ucred && pid_is_valid(ucred->pid)) {
r = client_context_get(m, ucred->pid, ucred, label, label_len, NULL, &context);
if (r < 0)
log_ratelimit_warning_errno(r, JOURNAL_LOG_RATELIMIT,
"Failed to retrieve credentials for PID " PID_FMT ", ignoring: %m",
ucred->pid);
}
do {
r = manager_process_entry(m,
(const uint8_t*) buffer + (buffer_size - remaining), &remaining,
context, ucred, tv, label, label_len);
} while (r == 0);
}
int manager_process_native_file(
Manager *m,
int fd,
const struct ucred *ucred,
const struct timeval *tv,
const char *label, size_t label_len) {
struct stat st;
bool sealed;
int r;
/* Data is in the passed fd, probably it didn't fit in a datagram. */
assert(m);
assert(fd >= 0);
if (fstat(fd, &st) < 0)
return log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
"Failed to stat passed file: %m");
r = stat_verify_regular(&st);
if (r < 0)
return log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
"File passed is not regular, ignoring message: %m");
if (st.st_size <= 0)
return 0;
r = fd_verify_safe_flags(fd);
if (r == -EREMOTEIO)
return log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
"Unexpected flags of passed memory fd, ignoring message.");
if (r < 0)
return log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
"Failed to get flags of passed file: %m");
/* If it's a memfd, check if it is sealed. If so, we can just mmap it and use it, and do not need to
* copy the data out. */
sealed = memfd_get_sealed(fd) > 0;
if (!sealed && (!ucred || ucred->uid != 0)) {
_cleanup_free_ char *k = NULL;
const char *e;
/* If this is not a sealed memfd, and the peer is unknown or unprivileged, then verify the
* path. */
r = fd_get_path(fd, &k);
if (r < 0)
return log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
"Failed to get path of passed fd: %m");
e = PATH_STARTSWITH_SET(k, "/dev/shm/", "/tmp/", "/var/tmp/");
if (!e)
return log_ratelimit_error_errno(SYNTHETIC_ERRNO(EPERM), JOURNAL_LOG_RATELIMIT,
"Received file outside of allowed directories, refusing.");
if (!filename_is_valid(e))
return log_ratelimit_error_errno(SYNTHETIC_ERRNO(EPERM), JOURNAL_LOG_RATELIMIT,
"Received file in subdirectory of allowed directories, refusing.");
}
/* When !sealed, set a lower memory limit. We have to read the file, effectively doubling memory
* use. */
if (st.st_size > ENTRY_SIZE_MAX / (sealed ? 1 : 2))
return log_ratelimit_error_errno(SYNTHETIC_ERRNO(EFBIG), JOURNAL_LOG_RATELIMIT,
"File passed too large (%"PRIu64" bytes), refusing.",
(uint64_t) st.st_size);
if (sealed) {
void *p;
size_t ps;
/* The file is sealed, we can just map it and use it. */
ps = PAGE_ALIGN(st.st_size);
assert(ps < SIZE_MAX);
p = mmap(NULL, ps, PROT_READ, MAP_PRIVATE, fd, 0);
if (p == MAP_FAILED)
return log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
"Failed to map memfd: %m");
manager_process_native_message(m, p, st.st_size, ucred, tv, label, label_len);
assert_se(munmap(p, ps) >= 0);
return 0;
}
_cleanup_free_ void *p = NULL;
struct statvfs vfs;
ssize_t n;
if (fstatvfs(fd, &vfs) < 0)
return log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
"Failed to stat file system of passed file: %m");
/* Refuse operating on file systems that have mandatory locking enabled.
* See also: https://github.com/systemd/systemd/issues/1822 */
if (FLAGS_SET(vfs.f_flag, ST_MANDLOCK))
return log_ratelimit_error_errno(SYNTHETIC_ERRNO(EPERM), JOURNAL_LOG_RATELIMIT,
"Received file descriptor from file system with mandatory locking enabled, not processing it.");
/* Make the fd non-blocking. On regular files this has the effect of bypassing mandatory
* locking. Of course, this should normally not be necessary given the check above, but let's
* better be safe than sorry, after all NFS is pretty confusing regarding file system flags,
* and we better don't trust it, and so is SMB. */
r = fd_nonblock(fd, true);
if (r < 0)
return log_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT,
"Failed to make fd non-blocking: %m");
/* The file is not sealed, we can't map the file here, since clients might then truncate it
* and trigger a SIGBUS for us. So let's stupidly read it. */
p = malloc(st.st_size);
if (!p)
return log_oom();
n = pread(fd, p, st.st_size, 0);
if (n < 0)
return log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT,
"Failed to read file: %m");
if (n > 0)
manager_process_native_message(m, p, n, ucred, tv, label, label_len);
return 0;
}
int manager_open_native_socket(Manager *m, const char *native_socket) {
int r;
assert(m);
assert(native_socket);
if (m->native_fd < 0) {
union sockaddr_union sa;
size_t sa_len;
r = sockaddr_un_set_path(&sa.un, native_socket);
if (r < 0)
return log_error_errno(r, "Unable to use namespace path %s for AF_UNIX socket: %m", native_socket);
sa_len = r;
m->native_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (m->native_fd < 0)
return log_error_errno(errno, "socket() failed: %m");
(void) sockaddr_un_unlink(&sa.un);
r = bind(m->native_fd, &sa.sa, sa_len);
if (r < 0)
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
(void) chmod(sa.un.sun_path, 0666);
} else
(void) fd_nonblock(m->native_fd, true);
r = setsockopt_int(m->native_fd, SOL_SOCKET, SO_PASSCRED, true);
if (r < 0)
return log_error_errno(r, "SO_PASSCRED failed: %m");
if (mac_selinux_use()) {
r = setsockopt_int(m->native_fd, SOL_SOCKET, SO_PASSSEC, true);
if (r < 0)
log_full_errno(ERRNO_IS_NEG_NOT_SUPPORTED(r) ? LOG_DEBUG : LOG_WARNING, r, "SO_PASSSEC failed, ignoring: %m");
}
r = setsockopt_int(m->native_fd, SOL_SOCKET, SO_TIMESTAMP, true);
if (r < 0)
return log_error_errno(r, "SO_TIMESTAMP failed: %m");
r = sd_event_add_io(m->event, &m->native_event_source, m->native_fd, EPOLLIN, manager_process_datagram, m);
if (r < 0)
return log_error_errno(r, "Failed to add native manager fd to event loop: %m");
r = sd_event_source_set_priority(m->native_event_source, SD_EVENT_PRIORITY_NORMAL+5);
if (r < 0)
return log_error_errno(r, "Failed to adjust native event source priority: %m");
return 0;
}
Reference in New Issue View Git Blame Copy Permalink