journald: split off native protocol support into its own .c file

1 files changed, 382 insertions, 0 deletions

diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
new file mode 100644
index 000000000..7aa99a399
--- /dev/null
+++ b/src/journal/journald-native.c
@@ -0,0 +1,382 @@
+/*-*- 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 <sys/epoll.h>
+
+#include "socket-util.h"
+#include "journald.h"
+#include "journald-native.h"
+#include "journald-kmsg.h"
+#include "journald-console.h"
+#include "journald-syslog.h"
+
+#define ENTRY_SIZE_MAX (1024*1024*32)
+
+static bool valid_user_field(const char *p, size_t l) {
+        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 (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;
+}
+
+void server_process_native_message(
+                Server *s,
+                const void *buffer, size_t buffer_size,
+                struct ucred *ucred,
+                struct timeval *tv,
+                const char *label, size_t label_len) {
+
+        struct iovec *iovec = NULL;
+        unsigned n = 0, m = 0, j, tn = (unsigned) -1;
+        const char *p;
+        size_t remaining;
+        int priority = LOG_INFO;
+        char *identifier = NULL, *message = NULL;
+
+        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 */
+                        server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority);
+                        n = 0;
+                        priority = LOG_INFO;
+
+                        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 */
+
+                if (n+N_IOVEC_META_FIELDS >= m) {
+                        struct iovec *c;
+                        unsigned u;
+
+                        u = MAX((n+N_IOVEC_META_FIELDS+1) * 2U, 4U);
+                        c = realloc(iovec, u * sizeof(struct iovec));
+                        if (!c) {
+                                log_oom();
+                                break;
+                        }
+
+                        iovec = c;
+                        m = u;
+                }
+
+                q = memchr(p, '=', e - p);
+                if (q) {
+                        if (valid_user_field(p, q - p)) {
+                                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;
+                                n++;
+
+                                /* We need to determine the priority
+                                 * of this entry for the rate limiting
+                                 * logic */
+                                if (l == 10 &&
+                                    memcmp(p, "PRIORITY=", 9) == 0 &&
+                                    p[9] >= '0' && p[9] <= '9')
+                                        priority = (priority & LOG_FACMASK) | (p[9] - '0');
+
+                                else if (l == 17 &&
+                                         memcmp(p, "SYSLOG_FACILITY=", 16) == 0 &&
+                                         p[16] >= '0' && p[16] <= '9')
+                                        priority = (priority & LOG_PRIMASK) | ((p[16] - '0') << 3);
+
+                                else if (l == 18 &&
+                                         memcmp(p, "SYSLOG_FACILITY=", 16) == 0 &&
+                                         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 &&
+                                         memcmp(p, "SYSLOG_IDENTIFIER=", 18) == 0) {
+                                        char *t;
+
+                                        t = strndup(p + 18, l - 18);
+                                        if (t) {
+                                                free(identifier);
+                                                identifier = t;
+                                        }
+                                } else if (l >= 8 &&
+                                           memcmp(p, "MESSAGE=", 8) == 0) {
+                                        char *t;
+
+                                        t = strndup(p + 8, l - 8);
+                                        if (t) {
+                                                free(message);
+                                                message = t;
+                                        }
+                                }
+                        }
+
+                        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 (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)) {
+                                iovec[n].iov_base = k;
+                                iovec[n].iov_len = (e - p) + 1 + l;
+                                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");
+
+        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);
+        }
+
+        server_dispatch_message(s, iovec, n, m, ucred, tv, label, label_len, NULL, priority);
+
+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,
+                struct ucred *ucred,
+                struct timeval *tv,
+                const char *label, size_t label_len) {
+
+        struct stat st;
+        void *p;
+        ssize_t n;
+
+        assert(s);
+        assert(fd >= 0);
+
+        /* Data is in the passed file, since it didn't fit in a
+         * datagram. 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 */
+
+        if (fstat(fd, &st) < 0) {
+                log_error("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;
+        }
+
+        p = malloc(st.st_size);
+        if (!p) {
+                log_oom();
+                return;
+        }
+
+        n = pread(fd, p, st.st_size, 0);
+        if (n < 0)
+                log_error("Failed to read file, ignoring: %s", strerror(-n));
+        else if (n > 0)
+                server_process_native_message(s, p, n, ucred, tv, label, label_len);
+
+        free(p);
+}
+
+int server_open_native_socket(Server*s) {
+        union sockaddr_union sa;
+        int one, r;
+        struct epoll_event ev;
+
+        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) {
+                        log_error("socket() failed: %m");
+                        return -errno;
+                }
+
+                zero(sa);
+                sa.un.sun_family = AF_UNIX;
+                strncpy(sa.un.sun_path, "/run/systemd/journal/socket", sizeof(sa.un.sun_path));
+
+                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) {
+                        log_error("bind() failed: %m");
+                        return -errno;
+                }
+
+                chmod(sa.un.sun_path, 0666);
+        } else
+                fd_nonblock(s->native_fd, 1);
+
+        one = 1;
+        r = setsockopt(s->native_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
+        if (r < 0) {
+                log_error("SO_PASSCRED failed: %m");
+                return -errno;
+        }
+
+#ifdef HAVE_SELINUX
+        one = 1;
+        r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one));
+        if (r < 0)
+                log_warning("SO_PASSSEC failed: %m");
+#endif
+
+        one = 1;
+        r = setsockopt(s->native_fd, SOL_SOCKET, SO_TIMESTAMP, &one, sizeof(one));
+        if (r < 0) {
+                log_error("SO_TIMESTAMP failed: %m");
+                return -errno;
+        }
+
+        zero(ev);
+        ev.events = EPOLLIN;
+        ev.data.fd = s->native_fd;
+        if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->native_fd, &ev) < 0) {
+                log_error("Failed to add native server fd to epoll object: %m");
+                return -errno;
+        }
+
+        return 0;
+}