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/usock.h>
  21 #include <libubox/uloop.h>
  22 #include "libubus.h"
  23
  24 enum {
  25         LOG_MSG,
  26         LOG_ID,
  27         LOG_PRIO,
  28         LOG_SOURCE,
  29         LOG_TIME,
  30         __LOG_MAX
  31 };
  32
  33 static const struct blobmsg_policy log_policy[] = {
  34         [LOG_MSG] = { .name = "msg", .type = BLOBMSG_TYPE_STRING },
  35         [LOG_ID] = { .name = "id", .type = BLOBMSG_TYPE_INT32 },
  36         [LOG_PRIO] = { .name = "priority", .type = BLOBMSG_TYPE_INT32 },
  37         [LOG_SOURCE] = { .name = "source", .type = BLOBMSG_TYPE_INT32 },
  38         [LOG_TIME] = { .name = "time", .type = BLOBMSG_TYPE_INT64 },
  39 };
  40
  41 enum {
  42         WATCH_ID,
  43         WATCH_COUNTER,
  44         __WATCH_MAX
  45 };
  46
  47 static struct ubus_subscriber log_event;
  48 static struct uloop_fd sender;
  49
  50 static void log_handle_remove(struct ubus_context *ctx, struct ubus_subscriber *s,
  51                         uint32_t id)
  52 {
  53         fprintf(stderr, "Object %08x went away\n", id);
  54 }
  55
  56 static int log_notify(struct ubus_context *ctx, struct ubus_object *obj,
  57                         struct ubus_request_data *req, const char *method,
  58                         struct blob_attr *msg)
  59 {
  60         struct blob_attr *tb[__LOG_MAX];
  61         char buf[256];
  62         char *str;
  63         time_t t;
  64         char *c;
  65
  66         blobmsg_parse(log_policy, ARRAY_SIZE(log_policy), tb, blob_data(msg), blob_len(msg));
  67         if (!tb[LOG_ID] || !tb[LOG_PRIO] || !tb[LOG_SOURCE] || !tb[LOG_TIME])
  68                 return 1;
  69
  70         t = blobmsg_get_u64(tb[LOG_TIME]) / 1000;
  71         c = ctime(&t);
  72         c[strlen(c) - 1] = '\0';
  73         str = blobmsg_format_json(msg, true);
  74         snprintf(buf, sizeof(buf), "%s - %s: %s\n",
  75                 c, (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("syslog") : ("kernel"), method);
  76         write(sender.fd, buf, strlen(buf));
  77
  78         free(str);
  79
  80         return 0;
  81 }
  82
  83 static void follow_log(struct ubus_context *ctx, int id, const char *url, const char *port)
  84 {
  85         int ret;
  86
  87         uloop_init();
  88         ubus_add_uloop(ctx);
  89
  90         log_event.remove_cb = log_handle_remove;
  91         log_event.cb = log_notify;
  92         ret = ubus_register_subscriber(ctx, &log_event);
  93         if (ret)
  94                 fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));
  95
  96         ret = ubus_subscribe(ctx, &log_event, id);
  97         if (ret)
  98                 fprintf(stderr, "Failed to add watch handler: %s\n", ubus_strerror(ret));
  99
 100         if (url && port) {
 101                 sender.fd = usock(USOCK_TCP | USOCK_NUMERIC, url, port);
 102                 if (sender.fd < 0) {
 103                         fprintf(stderr, "failed to connect: %s\n", strerror(errno));
 104                         exit(-1);
 105                 } else {
 106                         uloop_fd_add(&sender, ULOOP_READ);
 107                 }
 108         } else {
 109                 sender.fd = STDOUT_FILENO;
 110         }
 111
 112         uloop_run();
 113         ubus_free(ctx);
 114         uloop_done();
 115 }
 116
 117 enum {
 118         READ_LINE,
 119         __READ_MAX
 120 };
 121
 122 static const struct blobmsg_policy read_policy[] = {
 123         [READ_LINE] = { .name = "lines", .type = BLOBMSG_TYPE_ARRAY },
 124 };
 125
 126 static void read_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 127 {
 128         struct blob_attr *cur;
 129         struct blob_attr *_tb[__READ_MAX];
 130         time_t t;
 131         int rem;
 132
 133         if (!msg)
 134                 return;
 135
 136         blobmsg_parse(read_policy, ARRAY_SIZE(read_policy), _tb, blob_data(msg), blob_len(msg));
 137         if (!_tb[READ_LINE])
 138                 return;
 139         blobmsg_for_each_attr(cur, _tb[READ_LINE], rem) {
 140                 struct blob_attr *tb[__LOG_MAX];
 141                 char *c;
 142
 143                 if (blobmsg_type(cur) != BLOBMSG_TYPE_TABLE)
 144                         continue;
 145
 146                 blobmsg_parse(log_policy, ARRAY_SIZE(log_policy), tb, blobmsg_data(cur), blobmsg_data_len(cur));
 147                 if (!tb[LOG_MSG] || !tb[LOG_ID] || !tb[LOG_PRIO] || !tb[LOG_SOURCE] || !tb[LOG_TIME])
 148                         continue;
 149
 150                 t = blobmsg_get_u64(tb[LOG_TIME]);
 151                 c = ctime(&t);
 152                 c[strlen(c) - 1] = '\0';
 153                 printf("%s - %s: %s\n",
 154                         c, (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("syslog") : ("kernel"),
 155                         blobmsg_get_string(tb[LOG_MSG]));
 156         }
 157 }
 158
 159 static int usage(const char *prog)
 160 {
 161         fprintf(stderr, "Usage: %s [options]\n"
 162                 "Options:\n"
 163                 "    -s <path>          Path to ubus socket\n"
 164                 "    -l <count>         Got only the last 'count' messages\n"
 165                 "    -r <server> <port> Stream message to a server\n"
 166                 "    -f                 Follow log messages\n"
 167                 "\n", prog);
 168         return 1;
 169 }
 170
 171 int main(int argc, char **argv)
 172 {
 173         struct ubus_context *ctx;
 174         uint32_t id;
 175         const char *ubus_socket = NULL, *url = NULL, *port = NULL;
 176         int ch, ret, subscribe = 0, lines = 0;
 177         static struct blob_buf b;
 178
 179         while ((ch = getopt(argc, argv, "fs:l:r:")) != -1) {
 180                 switch (ch) {
 181                 case 's':
 182                         ubus_socket = optarg;
 183                         break;
 184                 case 'r':
 185                         url = optarg++;
 186                         port = argv[optind++];
 187                         break;
 188                 case 'f':
 189                         subscribe = 1;
 190                         break;
 191                 case 'l':
 192                         lines = atoi(optarg);
 193                         break;
 194                 default:
 195                         return usage(*argv);
 196                 }
 197         }
 198
 199         ctx = ubus_connect(ubus_socket);
 200         if (!ctx) {
 201                 fprintf(stderr, "Failed to connect to ubus\n");
 202                 return -1;
 203         }
 204
 205         ret = ubus_lookup_id(ctx, "log", &id);
 206         if (ret)
 207                 fprintf(stderr, "Failed to find log object: %s\n", ubus_strerror(ret));
 208
 209         if (!subscribe || lines) {
 210                 blob_buf_init(&b, 0);
 211                 if (lines)
 212                         blobmsg_add_u32(&b, "lines", lines);
 213                 ubus_invoke(ctx, id, "read", b.head, read_cb, 0, 3000);
 214         }
 215
 216         if (subscribe)
 217                 follow_log(ctx, id, url, port);
 218
 219         return 0;
 220 }