/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include "alloc-util.h" #include "fd-util.h" #include "fs-util.h" #include "io-util.h" #include "journal-importer.h" #include "journal-internal.h" #include "journal-util.h" #include "journald-client.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) { /* Ensure message is not NULL, otherwise strlen(message) would crash. This check needs to * be here until server_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 (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_ratelimit_warning_errno(r, JOURNAL_LOG_RATELIMIT, "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_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT, "readlink(/proc/self/fd/%i) failed: %m", fd); return; } e = PATH_STARTSWITH_SET(k, "/dev/shm/", "/tmp/", "/var/tmp/"); if (!e) { log_ratelimit_error(JOURNAL_LOG_RATELIMIT, "Received file outside of allowed directories. Refusing."); return; } if (!filename_is_valid(e)) { log_ratelimit_error(JOURNAL_LOG_RATELIMIT, "Received file in subdirectory of allowed directories. Refusing."); return; } } if (fstat(fd, &st) < 0) { log_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT, "Failed to stat passed file, ignoring: %m"); return; } if (!S_ISREG(st.st_mode)) { log_ratelimit_error(JOURNAL_LOG_RATELIMIT, "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_ratelimit_error(JOURNAL_LOG_RATELIMIT, "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_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT, "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_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT, "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_ratelimit_error(JOURNAL_LOG_RATELIMIT, "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_ratelimit_error_errno(r, JOURNAL_LOG_RATELIMIT, "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_ratelimit_error_errno(errno, JOURNAL_LOG_RATELIMIT, "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; }