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 <sys/types.h>
  15 #include <pwd.h>
  16 #include <stdio.h>
  17 #include <unistd.h>
  18 #include <syslog.h>
  19 #include <unistd.h>
  20
  21 #include <linux/types.h>
  22
  23 #include <libubox/uloop.h>
  24 #include <libubox/blobmsg.h>
  25 #include <libubox/list.h>
  26 #include <libubox/ustream.h>
  27 #include <libubox/utils.h>
  28 #include <libubus.h>
  29
  30 #include "syslog.h"
  31
  32 int debug = 0;
  33 static struct blob_buf b;
  34 static struct ubus_auto_conn conn;
  35 static struct udebug_ubus udebug;
  36 static LIST_HEAD(clients);
  37
  38 enum {
  39         READ_LINES,
  40         READ_STREAM,
  41         READ_ONESHOT,
  42         __READ_MAX
  43 };
  44
  45 static const struct blobmsg_policy read_policy[__READ_MAX] = {
  46         [READ_LINES] = { .name = "lines", .type = BLOBMSG_TYPE_INT32 },
  47         [READ_STREAM] = { .name = "stream", .type = BLOBMSG_TYPE_BOOL },
  48         [READ_ONESHOT] = { .name = "oneshot", .type = BLOBMSG_TYPE_BOOL },
  49 };
  50
  51 static const struct blobmsg_policy write_policy =
  52         { .name = "event", .type = BLOBMSG_TYPE_STRING };
  53
  54 struct client {
  55         struct list_head list;
  56
  57         struct ustream_fd s;
  58         int fd;
  59 };
  60
  61 static void
  62 client_close(struct ustream *s)
  63 {
  64         struct client *cl = container_of(s, struct client, s.stream);
  65
  66         list_del(&cl->list);
  67         ustream_free(s);
  68         close(cl->fd);
  69         free(cl);
  70 }
  71
  72 static void client_notify_state(struct ustream *s)
  73 {
  74         client_close(s);
  75 }
  76
  77 static void client_notify_write(struct ustream *s, int bytes)
  78 {
  79         if (ustream_pending_data(s, true))
  80                 return;
  81
  82         client_close(s);
  83 }
  84
  85 static void
  86 log_fill_msg(struct blob_buf *b, struct log_head *l)
  87 {
  88         blobmsg_add_string(b, "msg", l->data);
  89         blobmsg_add_u32(b, "id", l->id);
  90         blobmsg_add_u32(b, "priority", l->priority);
  91         blobmsg_add_u32(b, "source", l->source);
  92         blobmsg_add_u64(b, "time", (((__u64) l->ts.tv_sec) * 1000) + (l->ts.tv_nsec / 1000000));
  93 }
  94
  95 static int
  96 read_log(struct ubus_context *ctx, struct ubus_object *obj,
  97                 struct ubus_request_data *req, const char *method,
  98                 struct blob_attr *msg)
  99 {
 100         struct client *cl;
 101         struct blob_attr *tb[__READ_MAX] = {};
 102         struct log_head *l;
 103         int count = 0;
 104         int fds[2];
 105         int ret;
 106         bool stream = true;
 107         bool oneshot = false;
 108         void *c, *e;
 109
 110         if (!stream)
 111                 count = 100;
 112
 113         if (msg) {
 114                 blobmsg_parse(read_policy, __READ_MAX, tb, blob_data(msg), blob_len(msg));
 115                 if (tb[READ_LINES])
 116                         count = blobmsg_get_u32(tb[READ_LINES]);
 117                 if (tb[READ_STREAM])
 118                         stream = blobmsg_get_bool(tb[READ_STREAM]);
 119                 if (tb[READ_ONESHOT])
 120                         oneshot = blobmsg_get_bool(tb[READ_ONESHOT]);
 121         }
 122
 123         l = log_list(count, NULL);
 124         if (stream) {
 125                 if (pipe(fds) == -1) {
 126                         fprintf(stderr, "logd: failed to create pipe: %m\n");
 127                         return -1;
 128                 }
 129
 130                 ubus_request_set_fd(ctx, req, fds[0]);
 131                 cl = calloc(1, sizeof(*cl));
 132                 cl->s.stream.notify_state = client_notify_state;
 133                 cl->fd = fds[1];
 134                 ustream_fd_init(&cl->s, cl->fd);
 135                 list_add(&cl->list, &clients);
 136                 while ((!tb[READ_LINES] || count) && l) {
 137                         blob_buf_init(&b, 0);
 138                         log_fill_msg(&b, l);
 139                         l = log_list(count, l);
 140                         ret = ustream_write(&cl->s.stream, (void *) b.head, blob_len(b.head) + sizeof(struct blob_attr), false);
 141                         if (ret < 0)
 142                                 break;
 143                 }
 144
 145                 if (oneshot) {
 146                         cl->s.stream.notify_write = client_notify_write;
 147                         client_notify_write(&cl->s.stream, 0);
 148                 }
 149         } else {
 150                 blob_buf_init(&b, 0);
 151                 c = blobmsg_open_array(&b, "log");
 152                 while ((!tb[READ_LINES] || count) && l) {
 153                         e = blobmsg_open_table(&b, NULL);
 154                         log_fill_msg(&b, l);
 155                         blobmsg_close_table(&b, e);
 156                         l = log_list(count, l);
 157                 }
 158                 blobmsg_close_array(&b, c);
 159                 ubus_send_reply(ctx, req, b.head);
 160         }
 161         blob_buf_free(&b);
 162         return 0;
 163 }
 164
 165 static int
 166 write_log(struct ubus_context *ctx, struct ubus_object *obj,
 167                 struct ubus_request_data *req, const char *method,
 168                 struct blob_attr *msg)
 169 {
 170         struct blob_attr *tb;
 171         char *event;
 172
 173         if (msg) {
 174                 int len;
 175
 176                 blobmsg_parse(&write_policy, 1, &tb, blob_data(msg), blob_len(msg));
 177                 if (tb) {
 178                         event = blobmsg_get_string(tb);
 179                         len = strlen(event) + 1;
 180                         if (len > LOG_LINE_SIZE) {
 181                                 len = LOG_LINE_SIZE;
 182                                 event[len - 1] = 0;
 183                         }
 184
 185                         log_add(event, len, SOURCE_SYSLOG);
 186                 }
 187         }
 188
 189         return 0;
 190 }
 191
 192 static const struct ubus_method log_methods[] = {
 193         UBUS_METHOD("read", read_log, read_policy),
 194         { .name = "write", .handler = write_log, .policy = &write_policy, .n_policy = 1 },
 195 };
 196
 197 static struct ubus_object_type log_object_type =
 198         UBUS_OBJECT_TYPE("log", log_methods);
 199
 200 static struct ubus_object log_object = {
 201         .name = "log",
 202         .type = &log_object_type,
 203         .methods = log_methods,
 204         .n_methods = ARRAY_SIZE(log_methods),
 205 };
 206
 207 void
 208 ubus_notify_log(struct log_head *l)
 209 {
 210         struct client *c;
 211
 212         if (list_empty(&clients) && !log_object.has_subscribers)
 213                 return;
 214
 215         blob_buf_init(&b, 0);
 216         blobmsg_add_string(&b, "msg", l->data);
 217         blobmsg_add_u32(&b, "id", l->id);
 218         blobmsg_add_u32(&b, "priority", l->priority);
 219         blobmsg_add_u32(&b, "source", l->source);
 220         blobmsg_add_u64(&b, "time", (((__u64) l->ts.tv_sec) * 1000) + (l->ts.tv_nsec / 1000000));
 221
 222         if (log_object.has_subscribers)
 223                 ubus_notify(&conn.ctx, &log_object, "message", b.head, -1);
 224
 225         list_for_each_entry(c, &clients, list)
 226                 ustream_write(&c->s.stream, (void *) b.head, blob_len(b.head) + sizeof(struct blob_attr), false);
 227
 228         blob_buf_free(&b);
 229 }
 230
 231 static void
 232 ubus_connect_handler(struct ubus_context *ctx)
 233 {
 234         int ret;
 235
 236         ret = ubus_add_object(ctx, &log_object);
 237         if (ret) {
 238                 fprintf(stderr, "Failed to add object: %s\n", ubus_strerror(ret));
 239                 exit(1);
 240         }
 241         fprintf(stderr, "log: connected to ubus\n");
 242 }
 243
 244 int
 245 main(int argc, char **argv)
 246 {
 247         int ch, log_size = 16;
 248         struct passwd *p = NULL;
 249
 250         signal(SIGPIPE, SIG_IGN);
 251         while ((ch = getopt(argc, argv, "S:")) != -1) {
 252                 switch (ch) {
 253                 case 'S':
 254                         log_size = atoi(optarg);
 255                         if (log_size < 1)
 256                                 log_size = 16;
 257                         break;
 258                 }
 259         }
 260         log_size *= 1024;
 261
 262         uloop_init();
 263         log_init(log_size);
 264         conn.cb = ubus_connect_handler;
 265         ubus_auto_connect(&conn);
 266         udebug_ubus_init(&udebug, &conn.ctx, "log", log_udebug_config);
 267         p = getpwnam("logd");
 268         if (p) {
 269                 if (setgid(p->pw_gid) < 0) {
 270                         fprintf(stderr, "setgid() failed: %s\n", strerror(errno));
 271                         exit(1);
 272                 }
 273
 274                 if (setuid(p->pw_uid) < 0) {
 275                         fprintf(stderr, "setuid() failed: %s\n", strerror(errno));
 276                         exit(1);
 277                 }
 278         }
 279         uloop_run();
 280         udebug_ubus_free(&udebug);
 281         log_shutdown();
 282         uloop_done();
 283         ubus_auto_shutdown(&conn);
 284
 285         return 0;
 286 }