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-rw-r--r--src/journal/journald-native.c505
1 files changed, 505 insertions, 0 deletions
diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
new file mode 100644
index 0000000..0325788
--- /dev/null
+++ b/src/journal/journald-native.c
@@ -0,0 +1,505 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <stddef.h>
+#include <sys/epoll.h>
+#include <sys/mman.h>
+#include <sys/statvfs.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "journal-importer.h"
+#include "journal-util.h"
+#include "journald-console.h"
+#include "journald-kmsg.h"
+#include "journald-native.h"
+#include "journald-server.h"
+#include "journald-syslog.h"
+#include "journald-wall.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 "string-util.h"
+#include "strv.h"
+#include "unaligned.h"
+
+static bool allow_object_pid(const struct ucred *ucred) {
+ return ucred && ucred->uid == 0;
+}
+
+static void server_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 = (*priority & LOG_PRIMASK) | ((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 = (*priority & LOG_PRIMASK) | (((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(*identifier);
+ *identifier = t;
+ }
+
+ } else if (l >= 8 &&
+ startswith(p, "MESSAGE=")) {
+ char *t;
+
+ t = memdup_suffix0(p + 8, l - 8);
+ if (t) {
+ free(*message);
+ *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 server_process_entry(
+ Server *s,
+ 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;
+
+ server_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++;
+
+ server_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) {
+ if (s->forward_to_syslog)
+ server_forward_syslog(s, syslog_fixup_facility(priority), identifier, message, ucred, tv);
+
+ if (s->forward_to_kmsg)
+ server_forward_kmsg(s, priority, identifier, message, ucred);
+
+ if (s->forward_to_console)
+ server_forward_console(s, priority, identifier, message, ucred);
+
+ if (s->forward_to_wall)
+ server_forward_wall(s, priority, identifier, message, ucred);
+ }
+
+ server_dispatch_message(s, 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 server_process_native_message(
+ Server *s,
+ 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(s);
+ assert(buffer || buffer_size == 0);
+
+ if (ucred && pid_is_valid(ucred->pid)) {
+ r = client_context_get(s, ucred->pid, ucred, label, label_len, NULL, &context);
+ if (r < 0)
+ log_warning_errno(r, "Failed to retrieve credentials for PID " PID_FMT ", ignoring: %m", ucred->pid);
+ }
+
+ do {
+ r = server_process_entry(s,
+ (const uint8_t*) buffer + (buffer_size - remaining), &remaining,
+ context, ucred, tv, label, label_len);
+ } while (r == 0);
+}
+
+void server_process_native_file(
+ Server *s,
+ 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(s);
+ assert(fd >= 0);
+
+ /* 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) {
+ log_error_errno(r, "readlink(/proc/self/fd/%i) failed: %m", fd);
+ return;
+ }
+
+ e = PATH_STARTSWITH_SET(k, "/dev/shm/", "/tmp/", "/var/tmp/");
+ if (!e) {
+ log_error("Received file outside of allowed directories. Refusing.");
+ return;
+ }
+
+ if (!filename_is_valid(e)) {
+ log_error("Received file in subdirectory of allowed directories. Refusing.");
+ return;
+ }
+ }
+
+ if (fstat(fd, &st) < 0) {
+ log_error_errno(errno, "Failed to stat passed file, ignoring: %m");
+ return;
+ }
+
+ if (!S_ISREG(st.st_mode)) {
+ log_error("File passed is not regular. Ignoring.");
+ return;
+ }
+
+ if (st.st_size <= 0)
+ return;
+
+ /* 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)) {
+ log_error("File passed too large (%"PRIu64" bytes). Ignoring.", (uint64_t) st.st_size);
+ return;
+ }
+
+ 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);
+ p = mmap(NULL, ps, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (p == MAP_FAILED) {
+ log_error_errno(errno, "Failed to map memfd, ignoring: %m");
+ return;
+ }
+
+ server_process_native_message(s, p, st.st_size, ucred, tv, label, label_len);
+ assert_se(munmap(p, ps) >= 0);
+ } else {
+ _cleanup_free_ void *p = NULL;
+ struct statvfs vfs;
+ ssize_t n;
+
+ if (fstatvfs(fd, &vfs) < 0) {
+ log_error_errno(errno, "Failed to stat file system of passed file, not processing it: %m");
+ return;
+ }
+
+ /* Refuse operating on file systems that have
+ * mandatory locking enabled, see:
+ *
+ * https://github.com/systemd/systemd/issues/1822
+ */
+ if (vfs.f_flag & ST_MANDLOCK) {
+ log_error("Received file descriptor from file system with mandatory locking enabled, not processing it.");
+ return;
+ }
+
+ /* 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) {
+ log_error_errno(r, "Failed to make fd non-blocking, not processing it: %m");
+ return;
+ }
+
+ /* 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) {
+ log_oom();
+ return;
+ }
+
+ n = pread(fd, p, st.st_size, 0);
+ if (n < 0)
+ log_error_errno(errno, "Failed to read file, ignoring: %m");
+ else if (n > 0)
+ server_process_native_message(s, p, n, ucred, tv, label, label_len);
+ }
+}
+
+int server_open_native_socket(Server *s, const char *native_socket) {
+ int r;
+
+ assert(s);
+ assert(native_socket);
+
+ if (s->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;
+
+ s->native_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ if (s->native_fd < 0)
+ return log_error_errno(errno, "socket() failed: %m");
+
+ (void) sockaddr_un_unlink(&sa.un);
+
+ r = bind(s->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(s->native_fd, true);
+
+ r = setsockopt_int(s->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(s->native_fd, SOL_SOCKET, SO_PASSSEC, true);
+ if (r < 0)
+ log_warning_errno(r, "SO_PASSSEC failed: %m");
+ }
+
+ r = setsockopt_int(s->native_fd, SOL_SOCKET, SO_TIMESTAMP, true);
+ if (r < 0)
+ return log_error_errno(r, "SO_TIMESTAMP failed: %m");
+
+ r = sd_event_add_io(s->event, &s->native_event_source, s->native_fd, EPOLLIN, server_process_datagram, s);
+ if (r < 0)
+ return log_error_errno(r, "Failed to add native server fd to event loop: %m");
+
+ r = sd_event_source_set_priority(s->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;
+}
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