logread.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 <time.h>
  16 #include <unistd.h>
  17 #include <stdio.h>
  18
  19 #include <libubox/blobmsg_json.h>
  20 #include <libubox/uloop.h>
  21 #include "libubus.h"
  22
  23 enum {
  24         LOG_MSG,
  25         LOG_ID,
  26         LOG_PRIO,
  27         LOG_SOURCE,
  28         LOG_TIME,
  29         __LOG_MAX
  30 };
  31
  32 static const struct blobmsg_policy log_policy[] = {
  33         [LOG_MSG] = { .name = "msg", .type = BLOBMSG_TYPE_STRING },
  34         [LOG_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
  35         [LOG_PRIO] = { .name = "priority", .type = BLOBMSG_TYPE_INT32 },
  36         [LOG_SOURCE] = { .name = "source", .type = BLOBMSG_TYPE_INT32 },
  37         [LOG_TIME] = { .name = "time", .type = BLOBMSG_TYPE_INT64 },
  38 };
  39
  40 enum {
  41         WATCH_ID,
  42         WATCH_COUNTER,
  43         __WATCH_MAX
  44 };
  45
  46 static struct ubus_subscriber log_event;
  47
  48 static void log_handle_remove(struct ubus_context *ctx, struct ubus_subscriber *s,
  49                         uint32_t id)
  50 {
  51         fprintf(stderr, "Object %08x went away\n", id);
  52 }
  53
  54 static int log_notify(struct ubus_context *ctx, struct ubus_object *obj,
  55                         struct ubus_request_data *req, const char *method,
  56                         struct blob_attr *msg)
  57 {
  58         struct blob_attr *tb[__LOG_MAX];
  59         char *str;
  60         time_t t;
  61         char *c;
  62
  63         blobmsg_parse(log_policy, ARRAY_SIZE(log_policy), tb, blob_data(msg), blob_len(msg));
  64         if (!tb[LOG_ID] || !tb[LOG_PRIO] || !tb[LOG_SOURCE] || !tb[LOG_TIME])
  65                 return 1;
  66
  67         t = blobmsg_get_u64(tb[LOG_TIME]) / 1000;
  68         c = ctime(&t);
  69         c[strlen(c) - 1] = '\0';
  70         str = blobmsg_format_json(msg, true);
  71         printf("%s - %s: %s\n",
  72                 c, (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("syslog") : ("kernel"), method);
  73         free(str);
  74
  75         return 0;
  76 }
  77
  78 static void follow_log(struct ubus_context *ctx, int id)
  79 {
  80         int ret;
  81
  82         uloop_init();
  83         ubus_add_uloop(ctx);
  84
  85         log_event.remove_cb = log_handle_remove;
  86         log_event.cb = log_notify;
  87         ret = ubus_register_subscriber(ctx, &log_event);
  88         if (ret)
  89                 fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));
  90
  91         ret = ubus_subscribe(ctx, &log_event, id);
  92         if (ret)
  93                 fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));
  94
  95         uloop_run();
  96         ubus_free(ctx);
  97         uloop_done();
  98 }
  99
 100 enum {
 101         READ_LINE,
 102         __READ_MAX
 103 };
 104
 105 static const struct blobmsg_policy read_policy[] = {
 106         [READ_LINE] = { .name = "lines", .type = BLOBMSG_TYPE_ARRAY },
 107 };
 108
 109 static void read_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 110 {
 111         struct blob_attr *cur;
 112         struct blob_attr *_tb[__READ_MAX];
 113         time_t t;
 114         int rem;
 115
 116         if (!msg)
 117                 return;
 118
 119         blobmsg_parse(read_policy, ARRAY_SIZE(read_policy), _tb, blob_data(msg), blob_len(msg));
 120         if (!_tb[READ_LINE])
 121                 return;
 122         blobmsg_for_each_attr(cur, _tb[READ_LINE], rem) {
 123                 struct blob_attr *tb[__LOG_MAX];
 124                 char *c;
 125
 126                 if (blobmsg_type(cur) != BLOBMSG_TYPE_TABLE)
 127                         continue;
 128
 129                 blobmsg_parse(log_policy, ARRAY_SIZE(log_policy), tb, blobmsg_data(cur), blobmsg_data_len(cur));
 130                 if (!tb[LOG_MSG] || !tb[LOG_ID] || !tb[LOG_PRIO] || !tb[LOG_SOURCE] || !tb[LOG_TIME])
 131                         continue;
 132
 133                 t = blobmsg_get_u64(tb[LOG_TIME]) / 1000;
 134                 c = ctime(&t);
 135                 c[strlen(c) - 1] = '\0';
 136                 printf("%s - %s: %s\n",
 137                         c, (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("syslog") : ("kernel"),
 138                         blobmsg_get_string(tb[LOG_MSG]));
 139         }
 140 }
 141
 142 static int usage(const char *prog)
 143 {
 144         fprintf(stderr, "Usage: %s [options]\n"
 145                 "Options:\n"
 146                 "    -s <path>          Path to ubus socket\n"
 147                 "    -l <count>         Got only the last 'count' messages\n"
 148                 "    -f                 Follow log messages\n"
 149                 "\n", prog);
 150         return 1;
 151 }
 152
 153 int main(int argc, char **argv)
 154 {
 155         struct ubus_context *ctx;
 156         uint32_t id;
 157         const char *ubus_socket = NULL;
 158         int ch, ret, subscribe = 0, lines = 0;
 159         static struct blob_buf b;
 160
 161         while ((ch = getopt(argc, argv, "fs:l:")) != -1) {
 162                 switch (ch) {
 163                 case 's':
 164                         ubus_socket = optarg;
 165                         break;
 166                 case 'f':
 167                         subscribe = 1;
 168                         break;
 169                 case 'l':
 170                         lines = atoi(optarg);
 171                         break;
 172                 default:
 173                         usage(*argv);
 174                         break;
 175                 }
 176         }
 177
 178         ctx = ubus_connect(ubus_socket);
 179         if (!ctx) {
 180                 fprintf(stderr, "Failed to connect to ubus\n");
 181                 return -1;
 182         }
 183
 184         ret = ubus_lookup_id(ctx, "log", &id);
 185         if (ret)
 186                 fprintf(stderr, "Failed to find log object: %s\n", ubus_strerror(ret));
 187
 188         if (!subscribe || lines) {
 189                 blob_buf_init(&b, 0);
 190                 if (lines)
 191                         blobmsg_add_u32(&b, "lines", lines);
 192                 ubus_invoke(ctx, id, "read", b.head, read_cb, 0, 3000);
 193         }
 194
 195         if (subscribe)
 196                 follow_log(ctx, id);
 197
 198         return 0;
 199 }