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