log/logd.c

   1 /*
   2  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <stdio.h>
  15 #include <unistd.h>
  16 #include <syslog.h>
  17 #include <unistd.h>
  18
  19 #include <linux/types.h>
  20
  21 #include <libubox/uloop.h>
  22 #include <libubox/blobmsg.h>
  23 #include <libubox/list.h>
  24 #include <libubox/ustream.h>
  25 #include <libubus.h>
  26
  27 #include "syslog.h"
  28
  29 int debug = 0;
  30 static struct blob_buf b;
  31 static struct ubus_auto_conn conn;
  32 static LIST_HEAD(clients);
  33
  34 enum {
  35         READ_LINES,
  36         READ_STREAM,
  37         READ_ONESHOT,
  38         __READ_MAX
  39 };
  40
  41 static const struct blobmsg_policy read_policy[__READ_MAX] = {
  42         [READ_LINES] = { .name = "lines", .type = BLOBMSG_TYPE_INT32 },
  43         [READ_STREAM] = { .name = "stream", .type = BLOBMSG_TYPE_BOOL },
  44         [READ_ONESHOT] = { .name = "oneshot", .type = BLOBMSG_TYPE_BOOL },
  45 };
  46
  47 static const struct blobmsg_policy write_policy =
  48         { .name = "event", .type = BLOBMSG_TYPE_STRING };
  49
  50 struct client {
  51         struct list_head list;
  52
  53         struct ustream_fd s;
  54         int fd;
  55 };
  56
  57 static void
  58 client_close(struct ustream *s)
  59 {
  60         struct client *cl = container_of(s, struct client, s.stream);
  61
  62         list_del(&cl->list);
  63         ustream_free(s);
  64         close(cl->fd);
  65         free(cl);
  66 }
  67
  68 static void client_notify_state(struct ustream *s)
  69 {
  70         client_close(s);
  71 }
  72
  73 static void client_notify_write(struct ustream *s, int bytes)
  74 {
  75         if (ustream_pending_data(s, true))
  76                 return;
  77
  78         client_close(s);
  79 }
  80
  81 static void
  82 log_fill_msg(struct blob_buf *b, struct log_head *l)
  83 {
  84         blobmsg_add_string(b, "msg", l->data);
  85         blobmsg_add_u32(b, "id", l->id);
  86         blobmsg_add_u32(b, "priority", l->priority);
  87         blobmsg_add_u32(b, "source", l->source);
  88         blobmsg_add_u64(b, "time", (((__u64) l->ts.tv_sec) * 1000) + (l->ts.tv_nsec / 1000000));
  89 }
  90
  91 static int
  92 read_log(struct ubus_context *ctx, struct ubus_object *obj,
  93                 struct ubus_request_data *req, const char *method,
  94                 struct blob_attr *msg)
  95 {
  96         struct client *cl;
  97         struct blob_attr *tb[__READ_MAX] = {};
  98         struct log_head *l;
  99         int count = 0;
 100         int fds[2];
 101         int ret;
 102         bool stream = true;
 103         bool oneshot = false;
 104         void *c, *e;
 105
 106         if (!stream)
 107                 count = 100;
 108
 109         if (msg) {
 110                 blobmsg_parse(read_policy, __READ_MAX, tb, blob_data(msg), blob_len(msg));
 111                 if (tb[READ_LINES])
 112                         count = blobmsg_get_u32(tb[READ_LINES]);
 113                 if (tb[READ_STREAM])
 114                         stream = blobmsg_get_bool(tb[READ_STREAM]);
 115                 if (tb[READ_ONESHOT])
 116                         oneshot = blobmsg_get_bool(tb[READ_ONESHOT]);
 117         }
 118
 119         l = log_list(count, NULL);
 120         if (stream) {
 121                 if (pipe(fds) == -1) {
 122                         fprintf(stderr, "logd: failed to create pipe: %s\n", strerror(errno));
 123                         return -1;
 124                 }
 125
 126                 ubus_request_set_fd(ctx, req, fds[0]);
 127                 cl = calloc(1, sizeof(*cl));
 128                 cl->s.stream.notify_state = client_notify_state;
 129                 cl->fd = fds[1];
 130                 ustream_fd_init(&cl->s, cl->fd);
 131                 list_add(&cl->list, &clients);
 132                 while ((!tb[READ_LINES] || count) && l) {
 133                         blob_buf_init(&b, 0);
 134                         log_fill_msg(&b, l);
 135                         l = log_list(count, l);
 136                         ret = ustream_write(&cl->s.stream, (void *) b.head, blob_len(b.head) + sizeof(struct blob_attr), false);
 137                         if (ret < 0)
 138                                 break;
 139                 }
 140
 141                 if (oneshot) {
 142                         cl->s.stream.notify_write = client_notify_write;
 143                         client_notify_write(&cl->s.stream, 0);
 144                 }
 145         } else {
 146                 blob_buf_init(&b, 0);
 147                 c = blobmsg_open_array(&b, "log");
 148                 while ((!tb[READ_LINES] || count) && l) {
 149                         e = blobmsg_open_table(&b, NULL);
 150                         log_fill_msg(&b, l);
 151                         blobmsg_close_table(&b, e);
 152                         l = log_list(count, l);
 153                 }
 154                 blobmsg_close_array(&b, c);
 155                 ubus_send_reply(ctx, req, b.head);
 156         }
 157         blob_buf_free(&b);
 158         return 0;
 159 }
 160
 161 static int
 162 write_log(struct ubus_context *ctx, struct ubus_object *obj,
 163                 struct ubus_request_data *req, const char *method,
 164                 struct blob_attr *msg)
 165 {
 166         struct blob_attr *tb;
 167         char *event;
 168
 169         if (msg) {
 170                 int len;
 171
 172                 blobmsg_parse(&write_policy, 1, &tb, blob_data(msg), blob_len(msg));
 173                 if (tb) {
 174                         event = blobmsg_get_string(tb);
 175                         len = strlen(event) + 1;
 176                         if (len > LOG_LINE_SIZE) {
 177                                 len = LOG_LINE_SIZE;
 178                                 event[len - 1] = 0;
 179                         }
 180
 181                         log_add(event, len, SOURCE_SYSLOG);
 182                 }
 183         }
 184
 185         return 0;
 186 }
 187
 188 static const struct ubus_method log_methods[] = {
 189         UBUS_METHOD("read", read_log, read_policy),
 190         { .name = "write", .handler = write_log, .policy = &write_policy, .n_policy = 1 },
 191 };
 192
 193 static struct ubus_object_type log_object_type =
 194         UBUS_OBJECT_TYPE("log", log_methods);
 195
 196 static struct ubus_object log_object = {
 197         .name = "log",
 198         .type = &log_object_type,
 199         .methods = log_methods,
 200         .n_methods = ARRAY_SIZE(log_methods),
 201 };
 202
 203 void
 204 ubus_notify_log(struct log_head *l)
 205 {
 206         struct client *c;
 207
 208         if (list_empty(&clients))
 209                 return;
 210
 211         blob_buf_init(&b, 0);
 212         blobmsg_add_string(&b, "msg", l->data);
 213         blobmsg_add_u32(&b, "id", l->id);
 214         blobmsg_add_u32(&b, "priority", l->priority);
 215         blobmsg_add_u32(&b, "source", l->source);
 216         blobmsg_add_u64(&b, "time", (((__u64) l->ts.tv_sec) * 1000) + (l->ts.tv_nsec / 1000000));
 217
 218         list_for_each_entry(c, &clients, list)
 219                 ustream_write(&c->s.stream, (void *) b.head, blob_len(b.head) + sizeof(struct blob_attr), false);
 220
 221         blob_buf_free(&b);
 222 }
 223
 224 static void
 225 ubus_connect_handler(struct ubus_context *ctx)
 226 {
 227         int ret;
 228
 229         ret = ubus_add_object(ctx, &log_object);
 230         if (ret) {
 231                 fprintf(stderr, "Failed to add object: %s\n", ubus_strerror(ret));
 232                 exit(1);
 233         }
 234         fprintf(stderr, "log: connected to ubus\n");
 235 }
 236
 237 int
 238 main(int argc, char **argv)
 239 {
 240         int ch, log_size = 16;
 241
 242         signal(SIGPIPE, SIG_IGN);
 243         while ((ch = getopt(argc, argv, "S:")) != -1) {
 244                 switch (ch) {
 245                 case 'S':
 246                         log_size = atoi(optarg);
 247                         if (log_size < 1)
 248                                 log_size = 16;
 249                         break;
 250                 }
 251         }
 252         log_size *= 1024;
 253
 254         uloop_init();
 255         log_init(log_size);
 256         conn.cb = ubus_connect_handler;
 257         ubus_auto_connect(&conn);
 258         uloop_run();
 259         log_shutdown();
 260         uloop_done();
 261         ubus_auto_shutdown(&conn);
 262
 263         return 0;
 264 }