src/journal/journal-send.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <sys/socket.h>
  23 #include <sys/un.h>
  24 #include <errno.h>
  25 #include <stddef.h>
  26
  27 #include "sd-journal.h"
  28 #include "util.h"
  29 #include "socket-util.h"
  30
  31 /* We open a single fd, and we'll share it with the current process,
  32  * all its threads, and all its subprocesses. This means we need to
  33  * initialize it atomically, and need to operate on it atomically
  34  * never assuming we are the only user */
  35
  36 static int journal_fd(void) {
  37         int fd;
  38         static int fd_plus_one = 0;
  39
  40 retry:
  41         if (fd_plus_one > 0)
  42                 return fd_plus_one - 1;
  43
  44         fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
  45         if (fd < 0)
  46                 return -errno;
  47
  48         if (!__sync_bool_compare_and_swap(&fd_plus_one, 0, fd+1)) {
  49                 close_nointr_nofail(fd);
  50                 goto retry;
  51         }
  52
  53         return fd;
  54 }
  55
  56 int sd_journal_print(int priority, const char *format, ...) {
  57         int r;
  58         va_list ap;
  59
  60         va_start(ap, format);
  61         r = sd_journal_printv(priority, format, ap);
  62         va_end(ap);
  63
  64         return r;
  65 }
  66
  67 int sd_journal_printv(int priority, const char *format, va_list ap) {
  68         char buffer[8 + LINE_MAX], p[11];
  69         struct iovec iov[2];
  70
  71         if (priority < 0 || priority > 7)
  72                 return -EINVAL;
  73
  74         if (!format)
  75                 return -EINVAL;
  76
  77         snprintf(p, sizeof(p), "PRIORITY=%i", priority & LOG_PRIMASK);
  78         char_array_0(p);
  79
  80         memcpy(buffer, "MESSAGE=", 8);
  81         vsnprintf(buffer+8, sizeof(buffer) - 8, format, ap);
  82         char_array_0(buffer);
  83
  84         zero(iov);
  85         IOVEC_SET_STRING(iov[0], buffer);
  86         IOVEC_SET_STRING(iov[1], p);
  87
  88         return sd_journal_sendv(iov, 2);
  89 }
  90
  91 int sd_journal_send(const char *format, ...) {
  92         int r, n = 0, i = 0, j;
  93         va_list ap;
  94         struct iovec *iov = NULL;
  95
  96         va_start(ap, format);
  97         while (format) {
  98                 struct iovec *c;
  99                 char *buffer;
 100
 101                 if (i >= n) {
 102                         n = MAX(i*2, 4);
 103                         c = realloc(iov, n * sizeof(struct iovec));
 104                         if (!c) {
 105                                 r = -ENOMEM;
 106                                 goto fail;
 107                         }
 108
 109                         iov = c;
 110                 }
 111
 112                 if (vasprintf(&buffer, format, ap) < 0) {
 113                         r = -ENOMEM;
 114                         goto fail;
 115                 }
 116
 117                 IOVEC_SET_STRING(iov[i++], buffer);
 118
 119                 format = va_arg(ap, char *);
 120         }
 121         va_end(ap);
 122
 123         r = sd_journal_sendv(iov, i);
 124
 125 fail:
 126         for (j = 0; j < i; j++)
 127                 free(iov[j].iov_base);
 128
 129         free(iov);
 130
 131         return r;
 132 }
 133
 134 int sd_journal_sendv(const struct iovec *iov, int n) {
 135         int fd;
 136         struct iovec *w;
 137         uint64_t *l;
 138         int i, j = 0;
 139         struct msghdr mh;
 140         struct sockaddr_un sa;
 141
 142         if (!iov || n <= 0)
 143                 return -EINVAL;
 144
 145         w = alloca(sizeof(struct iovec) * n * 5);
 146         l = alloca(sizeof(uint64_t) * n);
 147
 148         for (i = 0; i < n; i++) {
 149                 char *c, *nl;
 150
 151                 c = memchr(iov[i].iov_base, '=', iov[i].iov_len);
 152                 if (!c)
 153                         return -EINVAL;
 154
 155                 nl = memchr(iov[i].iov_base, '\n', iov[i].iov_len);
 156                 if (nl) {
 157                         if (nl < c)
 158                                 return -EINVAL;
 159
 160                         /* Already includes a newline? Bummer, then
 161                          * let's write the variable name, then a
 162                          * newline, then the size (64bit LE), followed
 163                          * by the data and a final newline */
 164
 165                         w[j].iov_base = iov[i].iov_base;
 166                         w[j].iov_len = c - (char*) iov[i].iov_base;
 167                         j++;
 168
 169                         IOVEC_SET_STRING(w[j++], "\n");
 170
 171                         l[i] = htole64(iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1);
 172                         w[j].iov_base = &l[i];
 173                         w[j].iov_len = sizeof(uint64_t);
 174                         j++;
 175
 176                         w[j].iov_base = c + 1;
 177                         w[j].iov_len = iov[i].iov_len - (c - (char*) iov[i].iov_base) - 1;
 178                         j++;
 179
 180                 } else
 181                         /* Nothing special? Then just add the line and
 182                          * append a newline */
 183                         w[j++] = iov[i];
 184
 185                 IOVEC_SET_STRING(w[j++], "\n");
 186         }
 187
 188         fd = journal_fd();
 189         if (fd < 0)
 190                 return fd;
 191
 192         zero(sa);
 193         sa.sun_family = AF_UNIX;
 194         strncpy(sa.sun_path,"/run/systemd/journal", sizeof(sa.sun_path));
 195
 196         zero(mh);
 197         mh.msg_name = &sa;
 198         mh.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path);
 199         mh.msg_iov = w;
 200         mh.msg_iovlen = j;
 201
 202         if (sendmsg(fd, &mh, MSG_NOSIGNAL) < 0)
 203                 return -errno;
 204
 205         return 0;
 206 }
 207
 208 int sd_journal_stream_fd(const char *tag, int priority, int priority_prefix) {
 209         union sockaddr_union sa;
 210         int fd;
 211         char *header;
 212         size_t l;
 213         ssize_t r;
 214
 215         if (priority < 0 || priority > 7)
 216                 return -EINVAL;
 217
 218         fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
 219         if (fd < 0)
 220                 return -errno;
 221
 222         zero(sa);
 223         sa.un.sun_family = AF_UNIX;
 224         strncpy(sa.un.sun_path, "/run/systemd/stdout", sizeof(sa.un.sun_path));
 225
 226         r = connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
 227         if (r < 0) {
 228                 close_nointr_nofail(fd);
 229                 return -errno;
 230         }
 231
 232         if (!tag)
 233                 tag = "";
 234
 235         l = strlen(tag);
 236         header = alloca(l + 1 + 2 + 2 + 2);
 237
 238         memcpy(header, tag, l);
 239         header[l++] = '\n';
 240         header[l++] = '0' + priority;
 241         header[l++] = '\n';
 242         header[l++] = '0' + !!priority_prefix;
 243         header[l++] = '\n';
 244         header[l++] = '0';
 245         header[l++] = '\n';
 246
 247         r = loop_write(fd, header, l, false);
 248         if (r < 0) {
 249                 close_nointr_nofail(fd);
 250                 return (int) r;
 251         }
 252
 253         if ((size_t) r != l) {
 254                 close_nointr_nofail(fd);
 255                 return -errno;
 256         }
 257
 258         return fd;
 259 }