lib/log_filter.c

   1 /*
   2  * Logging - Filtered file log target
   3  * Copyright (C) 2019 Cumulus Networks, Inc.
   4  *                    Stephen Worley
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22
  23 #include "frr_pthread.h"
  24 #include "log.h"
  25
  26 static pthread_mutex_t logfilterlock = PTHREAD_MUTEX_INITIALIZER;
  27 static char zlog_filters[ZLOG_FILTERS_MAX][ZLOG_FILTER_LENGTH_MAX + 1];
  28 static uint8_t zlog_filter_count;
  29
  30 /*
  31  * look for a match on the filter in the current filters,
  32  * logfilterlock must be held
  33  */
  34 static int zlog_filter_lookup(const char *lookup)
  35 {
  36         for (int i = 0; i < zlog_filter_count; i++) {
  37                 if (strncmp(lookup, zlog_filters[i], sizeof(zlog_filters[0]))
  38                     == 0)
  39                         return i;
  40         }
  41         return -1;
  42 }
  43
  44 void zlog_filter_clear(void)
  45 {
  46         frr_with_mutex (&logfilterlock) {
  47                 zlog_filter_count = 0;
  48         }
  49 }
  50
  51 int zlog_filter_add(const char *filter)
  52 {
  53         frr_with_mutex (&logfilterlock) {
  54                 if (zlog_filter_count >= ZLOG_FILTERS_MAX)
  55                         return 1;
  56
  57                 if (zlog_filter_lookup(filter) != -1)
  58                         /* Filter already present */
  59                         return -1;
  60
  61                 strlcpy(zlog_filters[zlog_filter_count], filter,
  62                         sizeof(zlog_filters[0]));
  63
  64                 if (zlog_filters[zlog_filter_count][0] == '\0')
  65                         /* Filter was either empty or didn't get copied
  66                          * correctly
  67                          */
  68                         return -1;
  69
  70                 zlog_filter_count++;
  71         }
  72         return 0;
  73 }
  74
  75 int zlog_filter_del(const char *filter)
  76 {
  77         frr_with_mutex (&logfilterlock) {
  78                 int found_idx = zlog_filter_lookup(filter);
  79                 int last_idx = zlog_filter_count - 1;
  80
  81                 if (found_idx == -1)
  82                         /* Didn't find the filter to delete */
  83                         return -1;
  84
  85                 /* Adjust the filter array */
  86                 memmove(zlog_filters[found_idx], zlog_filters[found_idx + 1],
  87                         (last_idx - found_idx) * sizeof(zlog_filters[0]));
  88
  89                 zlog_filter_count--;
  90         }
  91         return 0;
  92 }
  93
  94 /* Dump all filters to buffer, delimited by new line */
  95 int zlog_filter_dump(char *buf, size_t max_size)
  96 {
  97         int len = 0;
  98
  99         frr_with_mutex (&logfilterlock) {
 100                 for (int i = 0; i < zlog_filter_count; i++) {
 101                         int ret;
 102
 103                         ret = snprintf(buf + len, max_size - len, " %s\n",
 104                                        zlog_filters[i]);
 105                         len += ret;
 106                         if ((ret < 0) || ((size_t)len >= max_size))
 107                                 return -1;
 108                 }
 109         }
 110
 111         return len;
 112 }
 113
 114 static int search_buf(const char *buf, size_t len)
 115 {
 116         char *found = NULL;
 117
 118         frr_with_mutex (&logfilterlock) {
 119                 for (int i = 0; i < zlog_filter_count; i++) {
 120                         found = memmem(buf, len, zlog_filters[i],
 121                                        strlen(zlog_filters[i]));
 122                         if (found != NULL)
 123                                 return 0;
 124                 }
 125         }
 126
 127         return -1;
 128 }
 129
 130 static void zlog_filterfile_fd(struct zlog_target *zt, struct zlog_msg *msgs[],
 131                                size_t nmsgs)
 132 {
 133         struct zlog_msg *msgfilt[nmsgs];
 134         size_t i, o = 0;
 135         const char *text;
 136         size_t text_len;
 137
 138         for (i = 0; i < nmsgs; i++) {
 139                 if (zlog_msg_prio(msgs[i]) >= LOG_DEBUG) {
 140                         text = zlog_msg_text(msgs[i], &text_len);
 141                         if (search_buf(text, text_len) < 0)
 142                                 continue;
 143                 }
 144                 msgfilt[o++] = msgs[i];
 145         }
 146
 147         if (o)
 148                 zlog_fd(zt, msgfilt, o);
 149 }
 150
 151 void zlog_filterfile_init(struct zlog_cfg_filterfile *zcf)
 152 {
 153         zlog_file_init(&zcf->parent);
 154         zcf->parent.zlog_wrap = zlog_filterfile_fd;
 155 }
 156
 157 void zlog_filterfile_fini(struct zlog_cfg_filterfile *zcf)
 158 {
 159         zlog_file_fini(&zcf->parent);
 160 }