+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- 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 <unistd.h>
-#include <stddef.h>
-#include <sys/epoll.h>
-#include <sys/mman.h>
-
-#include "socket-util.h"
-#include "path-util.h"
-#include "selinux-util.h"
-#include "journald-server.h"
-#include "journald-native.h"
-#include "journald-kmsg.h"
-#include "journald-console.h"
-#include "journald-syslog.h"
-#include "journald-wall.h"
-#include "memfd-util.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;
-}
-
-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) {
-
- struct iovec *iovec = NULL;
- unsigned n = 0, j, tn = (unsigned) -1;
- const char *p;
- size_t remaining, m = 0, entry_size = 0;
- int priority = LOG_INFO;
- char *identifier = NULL, *message = NULL;
- pid_t object_pid = 0;
-
- assert(s);
- assert(buffer || buffer_size == 0);
-
- p = buffer;
- remaining = buffer_size;
-
- 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;
- }
-
- if (e == p) {
- /* Entry separator */
-
- 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);
- continue;
- }
-
- server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority, object_pid);
- n = 0;
- priority = LOG_INFO;
- entry_size = 0;
-
- p++;
- remaining--;
- continue;
- }
-
- 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)) {
- 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 indidates a trusted
- * field */
- iovec[n].iov_base = (char*) p;
- iovec[n].iov_len = l;
- entry_size += iovec[n].iov_len;
- n++;
-
- /* 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="));
- char_array_0(buf);
-
- /* ignore error */
- parse_pid(buf, &object_pid);
- }
- }
-
- remaining -= (e - p) + 1;
- p = e + 1;
- continue;
- } else {
- le64_t l_le;
- uint64_t l;
- char *k;
-
- if (remaining < e - p + 1 + sizeof(uint64_t) + 1) {
- log_debug("Failed to parse message, ignoring.");
- break;
- }
-
- memcpy(&l_le, e + 1, sizeof(uint64_t));
- l = le64toh(l_le);
-
- 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++;
- } 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_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, 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 uint8_t*) iovec[j].iov_base >= (const uint8_t*) buffer + buffer_size)
- free(iovec[j].iov_base);
- }
-
- free(iovec);
- free(identifier);
- free(message);
-}
-
-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(errno, "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;
- ssize_t n;
-
- /* 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(n, "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 int one = 1;
- int r;
-
- assert(s);
-
- if (s->native_fd < 0) {
- union sockaddr_union sa = {
- .un.sun_family = AF_UNIX,
- .un.sun_path = "/run/systemd/journal/socket",
- };
-
- 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");
-
- unlink(sa.un.sun_path);
-
- r = bind(s->native_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
- if (r < 0)
- return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
-
- 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");
-
- return 0;
-}
~ianmdlvl / elogind.git / blobdiff