syslog.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/un.h>
  16
  17 #include <sys/types.h>
  18 #include <sys/socket.h>
  19 #include <sys/stat.h>
  20
  21 #include <fcntl.h>
  22 #include <regex.h>
  23 #include <time.h>
  24 #include <unistd.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <stdio.h>
  28
  29 #include <libubox/uloop.h>
  30 #include <libubox/usock.h>
  31 #include <libubox/ustream.h>
  32
  33 #include "procd.h"
  34 #include "syslog.h"
  35
  36 #define LOG_DEFAULT_SIZE        (16 * 1024)
  37 #define LOG_DEFAULT_SOCKET      "/dev/log"
  38 #define LOG_LINE_LEN            256
  39 #define SYSLOG_PADDING          16
  40
  41 #define KLOG_DEFAULT_PROC       "/proc/kmsg"
  42
  43 #define PAD(x) (x % 4) ? (((x) - (x % 4)) + 4) : (x)
  44
  45 static char *log_dev = LOG_DEFAULT_SOCKET;
  46 static int log_size = LOG_DEFAULT_SIZE;
  47 static struct log_head *log, *log_end, *oldest, *newest;
  48 static int current_id = 0;
  49 static regex_t pat_prio;
  50 static regex_t pat_tstamp;
  51
  52 static struct log_head *log_next(struct log_head *h, int size)
  53 {
  54         struct log_head *n = (struct log_head *) &h->data[PAD(sizeof(struct log_head) + size)];
  55
  56         return (n >= log_end) ? (log) : (n);
  57 }
  58
  59 void log_add(char *buf, int size, int source)
  60 {
  61         regmatch_t matches[4];
  62         struct log_head *next;
  63         int priority = 0;
  64         int ret;
  65
  66         /* strip trailing newline */
  67         if (buf[size - 2] == '\n') {
  68                 buf[size - 2] = '\0';
  69                 size -= 1;
  70         }
  71
  72         /* strip the priority */
  73         ret = regexec(&pat_prio, buf, 3, matches, 0);
  74         if (!ret) {
  75                 priority = atoi(&buf[matches[1].rm_so]);
  76                 size -= matches[2].rm_so;
  77                 buf += matches[2].rm_so;
  78         }
  79
  80 #if 0
  81         /* strip kernel timestamp */
  82         ret = regexec(&pat_tstamp,buf, 4, matches, 0);
  83         if ((source == SOURCE_KLOG) && !ret) {
  84                 size -= matches[3].rm_so;
  85                 buf += matches[3].rm_so;
  86         }
  87 #endif
  88
  89         /* strip syslog timestamp */
  90         if ((source == SOURCE_SYSLOG) && (size > SYSLOG_PADDING) && (buf[SYSLOG_PADDING - 1] == ' ')) {
  91                 size -= SYSLOG_PADDING;
  92                 buf += SYSLOG_PADDING;
  93         }
  94
  95         DEBUG(2, "-> %d - %s\n", priority, buf);
  96
  97         /* find new oldest entry */
  98         next = log_next(newest, size);
  99         if (next > newest) {
 100                 while ((oldest > newest) && (oldest <= next) && (oldest != log))
 101                         oldest = log_next(oldest, oldest->size);
 102         } else {
 103                 DEBUG(2, "Log wrap\n");
 104                 newest->size = 0;
 105                 next = log_next(log, size);
 106                 for (oldest = log; oldest <= next; oldest = log_next(oldest, oldest->size))
 107                         ;
 108                 newest = log;
 109         }
 110
 111         /* add the log message */
 112         newest->size = size;
 113         newest->id = current_id++;
 114         newest->priority = priority;
 115         newest->source = source;
 116         clock_gettime(CLOCK_REALTIME, &newest->ts);
 117         strcpy(newest->data, buf);
 118
 119         ubus_notify_log(newest);
 120
 121         newest = next;
 122 }
 123
 124 static void slog_cb(struct ustream *s, int bytes)
 125 {
 126         struct ustream_buf *buf = s->r.head;
 127         char *str;
 128         int len;
 129
 130         do {
 131                 str = ustream_get_read_buf(s, NULL);
 132                 if (!str)
 133                         break;
 134                 len = strlen(buf->data);
 135                 if (!len) {
 136                         bytes -= 1;
 137                         ustream_consume(s, 1);
 138                         continue;
 139                 }
 140                 log_add(buf->data, len + 1, SOURCE_SYSLOG);
 141                 ustream_consume(s, len);
 142                 bytes -= len;
 143         } while (bytes > 0);
 144 }
 145
 146 static void klog_cb(struct ustream *s, int bytes)
 147 {
 148         struct ustream_buf *buf = s->r.head;
 149         char *newline, *str;
 150         int len;
 151
 152         do {
 153                 str = ustream_get_read_buf(s, NULL);
 154                 if (!str)
 155                         break;
 156                 newline = strchr(buf->data, '\n');
 157                 if (!newline)
 158                         break;
 159                 *newline = 0;
 160                 len = newline + 1 - str;
 161                 log_add(buf->data, len, SOURCE_KLOG);
 162                 ustream_consume(s, len);
 163         } while (1);
 164 }
 165
 166 struct ustream_fd slog = {
 167         .stream.string_data = true,
 168         .stream.notify_read = slog_cb,
 169 };
 170
 171 struct ustream_fd klog = {
 172         .stream.string_data = true,
 173         .stream.notify_read = klog_cb,
 174 };
 175
 176 static int klog_open(void)
 177 {
 178         int fd;
 179
 180         DEBUG(1, "Opening %s\n", KLOG_DEFAULT_PROC);
 181         fd = open(KLOG_DEFAULT_PROC, O_RDONLY | O_NONBLOCK);
 182         if (fd < 0) {
 183                 ERROR("Failed to open %s\n", KLOG_DEFAULT_PROC);
 184                 return -1;
 185         }
 186         fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
 187         ustream_fd_init(&klog, fd);
 188         return 0;
 189 }
 190
 191 static int syslog_open(void)
 192 {
 193         int fd;
 194
 195         DEBUG(1, "Opening %s\n", log_dev);
 196         unlink(log_dev);
 197         fd = usock(USOCK_UNIX | USOCK_UDP |  USOCK_SERVER | USOCK_NONBLOCK, log_dev, NULL);
 198         if (fd < 0) {
 199                 ERROR("Failed to open %s\n", log_dev);
 200                 return -1;
 201         }
 202         chmod(log_dev, 0666);
 203         ustream_fd_init(&slog, fd);
 204         return 0;
 205 }
 206
 207 struct log_head* log_list(int count, struct log_head *h)
 208 {
 209         unsigned int min = count;
 210
 211         if (count)
 212                 min = (count < current_id) ? (current_id - count) : (0);
 213         if (!h && oldest->id >= min)
 214                 return oldest;
 215         if (!h)
 216                 h = oldest;
 217
 218         while (h != newest) {
 219                 h = log_next(h, h->size);
 220                 if (!h->size && (h > newest))
 221                         h = log;
 222                 if (h->id >= min && (h != newest))
 223                         return h;
 224         }
 225
 226         return NULL;
 227 }
 228
 229 int log_buffer_init(int size)
 230 {
 231         struct log_head *_log = malloc(size);
 232
 233         if (!_log) {
 234                 ERROR("Failed to initialize log buffer with size %d\n", log_size);
 235                 return -1;
 236         }
 237
 238         memset(_log, 0, size);
 239
 240         if (log && ((log_size + sizeof(struct log_head)) < size)) {
 241                 struct log_head *start = _log;
 242                 struct log_head *end = ((void*) _log) + size;
 243                 struct log_head *l;
 244
 245                 l = log_list(0, NULL);
 246                 while ((start < end) && l && l->size) {
 247                         memcpy(start, l, PAD(sizeof(struct log_head) + l->size));
 248                         start = (struct log_head *) &l->data[PAD(l->size)];
 249                         l = log_list(0, l);
 250                 }
 251                 free(log);
 252                 newest = start;
 253                 newest->size = 0;
 254                 oldest = log = _log;
 255                 log_end = ((void*) log) + size;
 256         } else {
 257                 oldest = newest = log = _log;
 258                 log_end = ((void*) log) + size;
 259         }
 260         log_size = size;
 261
 262         return 0;
 263 }
 264
 265 void log_init(void)
 266 {
 267         regcomp(&pat_prio, "^<([0-9]*)>(.*)", REG_EXTENDED);
 268         regcomp(&pat_tstamp, "^\[[ 0]*([0-9]*).([0-9]*)] (.*)", REG_EXTENDED);
 269
 270         if (log_buffer_init(log_size)) {
 271                 ERROR("Failed to allocate log memory\n");
 272                 exit(-1);
 273         }
 274
 275         syslog_open();
 276         klog_open();
 277         openlog("procd", LOG_PID, LOG_DAEMON);
 278 }