| /*** |
| This file is part of systemd. |
| |
| Copyright 2011 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #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 "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 "parse-util.h" |
| #include "path-util.h" |
| #include "selinux-util.h" |
| #include "socket-util.h" |
| #include "string-util.h" |
| #include "unaligned.h" |
| |
| bool valid_user_field(const char *p, size_t l, bool allow_protected) { |
| const char *a; |
| |
| /* We kinda enforce POSIX syntax recommendations for |
| environment variables here, but make a couple of additional |
| requirements. |
| |
| http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html */ |
| |
| /* No empty field names */ |
| if (l <= 0) |
| return false; |
| |
| /* Don't allow names longer than 64 chars */ |
| if (l > 64) |
| return false; |
| |
| /* Variables starting with an underscore are protected */ |
| if (!allow_protected && p[0] == '_') |
| return false; |
| |
| /* Don't allow digits as first character */ |
| if (p[0] >= '0' && p[0] <= '9') |
| return false; |
| |
| /* Only allow A-Z0-9 and '_' */ |
| for (a = p; a < p + l; a++) |
| if ((*a < 'A' || *a > 'Z') && |
| (*a < '0' || *a > '9') && |
| *a != '_') |
| return false; |
| |
| return true; |
| } |
| |
| 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 = strndup(p + 18, l - 18); |
| if (t) { |
| free(*identifier); |
| *identifier = t; |
| } |
| |
| } else if (l >= 8 && |
| startswith(p, "MESSAGE=")) { |
| char *t; |
| |
| t = strndup(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, |
| 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. */ |
| |
| struct iovec *iovec = NULL; |
| unsigned n = 0, j, tn = (unsigned) -1; |
| const char *p; |
| size_t m = 0, entry_size = 0; |
| int priority = LOG_INFO; |
| char *identifier = NULL, *message = NULL; |
| pid_t object_pid = 0; |
| int r = 0; |
| |
| 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."); |
| r = 1; /* finish processing of the message */ |
| break; |
| } |
| |
| if (e == p) { |
| /* Entry separator */ |
| *remaining -= 1; |
| break; |
| } |
| |
| if (*p == '.' || *p == '#') { |
| /* Ignore control commands for now, and |
| * comments too. */ |
| *remaining -= (e - p) + 1; |
| p = e + 1; |
| continue; |
| } |
| |
| /* A property follows */ |
| |
| /* n existing properties, 1 new, +1 for _TRANSPORT */ |
| if (!GREEDY_REALLOC(iovec, m, n + 2 + N_IOVEC_META_FIELDS + N_IOVEC_OBJECT_FIELDS)) { |
| r = log_oom(); |
| break; |
| } |
| |
| q = memchr(p, '=', e - p); |
| if (q) { |
| if (valid_user_field(p, q - p, false)) { |
| size_t l; |
| |
| l = e - p; |
| |
| /* If the field name starts with an |
| * underscore, skip the variable, |
| * since that indicates a trusted |
| * field */ |
| iovec[n].iov_base = (char*) p; |
| iovec[n].iov_len = l; |
| entry_size += l; |
| n++; |
| |
| server_process_entry_meta(p, l, ucred, |
| &priority, |
| &identifier, |
| &message, |
| &object_pid); |
| } |
| |
| *remaining -= (e - p) + 1; |
| p = e + 1; |
| continue; |
| } else { |
| uint64_t l; |
| 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.", l); |
| break; |
| } |
| |
| 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((e - p) + 1 + l); |
| 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 (valid_user_field(p, e - p, false)) { |
| iovec[n].iov_base = k; |
| iovec[n].iov_len = (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) { |
| r = 1; |
| goto finish; |
| } |
| |
| tn = n++; |
| IOVEC_SET_STRING(iovec[tn], "_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 %u properties and %zu bytes, ignoring.", |
| n, entry_size); |
| 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, m, ucred, tv, label, label_len, NULL, 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 void *buffer, size_t buffer_size, |
| const struct ucred *ucred, |
| const struct timeval *tv, |
| const char *label, size_t label_len) { |
| |
| int r; |
| size_t remaining = buffer_size; |
| |
| assert(s); |
| assert(buffer || buffer_size == 0); |
| |
| do { |
| r = server_process_entry(s, |
| (const uint8_t*) buffer + (buffer_size - remaining), &remaining, |
| 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, since 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 |
| * use map 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 *sl = NULL, *k = NULL; |
| const char *e; |
| |
| /* If this is not a sealed memfd, and the peer is unknown or |
| * unprivileged, then verify the path. */ |
| |
| if (asprintf(&sl, "/proc/self/fd/%i", fd) < 0) { |
| log_oom(); |
| return; |
| } |
| |
| r = readlink_malloc(sl, &k); |
| if (r < 0) { |
| log_error_errno(r, "readlink(%s) failed: %m", sl); |
| return; |
| } |
| |
| e = path_startswith(k, "/dev/shm/"); |
| if (!e) |
| e = path_startswith(k, "/tmp/"); |
| if (!e) |
| e = path_startswith(k, "/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; |
| |
| if (st.st_size > ENTRY_SIZE_MAX) { |
| log_error("File passed too large. Ignoring."); |
| 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, ignoring: %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 enable, refusing."); |
| 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, ignoring: %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) { |
| |
| static const union sockaddr_union sa = { |
| .un.sun_family = AF_UNIX, |
| .un.sun_path = "/run/systemd/journal/socket", |
| }; |
| static const int one = 1; |
| int r; |
| |
| assert(s); |
| |
| if (s->native_fd < 0) { |
| 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) unlink(sa.un.sun_path); |
| |
| r = bind(s->native_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)); |
| if (r < 0) |
| return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path); |
| |
| (void) chmod(sa.un.sun_path, 0666); |
| } else |
| fd_nonblock(s->native_fd, 1); |
| |
| r = setsockopt(s->native_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->native_fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one)); |
| if (r < 0) |
| log_warning_errno(errno, "SO_PASSSEC failed: %m"); |
| } |
| #endif |
| |
| r = setsockopt(s->native_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->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; |
| } |