ubusd_main.c

   1 /*
   2  * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  */
   6
   7 #include <sys/socket.h>
   8 #include <sys/stat.h>
   9 #ifdef FreeBSD
  10 #include <sys/param.h>
  11 #endif
  12 #include <syslog.h>
  13
  14 #include <libubox/usock.h>
  15
  16 #include "ubusd.h"
  17
  18 static void handle_client_disconnect(struct ubus_client *cl)
  19 {
  20         struct ubus_msg_buf_list *ubl, *ubl2;
  21         list_for_each_entry_safe(ubl, ubl2, &cl->tx_queue, list)
  22                 ubus_msg_list_free(ubl);
  23
  24         ubusd_monitor_disconnect(cl);
  25         ubusd_proto_free_client(cl);
  26         if (cl->pending_msg_fd >= 0)
  27                 close(cl->pending_msg_fd);
  28         uloop_fd_delete(&cl->sock);
  29         close(cl->sock.fd);
  30         free(cl);
  31 }
  32
  33 static void client_cb(struct uloop_fd *sock, unsigned int events)
  34 {
  35         struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
  36         uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
  37         struct msghdr msghdr = { 0 };
  38         struct ubus_msg_buf *ub;
  39         struct ubus_msg_buf_list *ubl, *ubl2;
  40         static struct iovec iov;
  41         struct cmsghdr *cmsg;
  42         int *pfd;
  43
  44         msghdr.msg_iov = &iov,
  45         msghdr.msg_iovlen = 1,
  46         msghdr.msg_control = fd_buf;
  47         msghdr.msg_controllen = sizeof(fd_buf);
  48
  49         cmsg = CMSG_FIRSTHDR(&msghdr);
  50         cmsg->cmsg_type = SCM_RIGHTS;
  51         cmsg->cmsg_level = SOL_SOCKET;
  52         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  53
  54         pfd = (int *) CMSG_DATA(cmsg);
  55         msghdr.msg_controllen = cmsg->cmsg_len;
  56
  57         /* first try to tx more pending data */
  58         list_for_each_entry_safe(ubl, ubl2, &cl->tx_queue, list) {
  59                 ssize_t written;
  60
  61                 ub = ubl->msg;
  62                 written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
  63                 if (written < 0) {
  64                         switch(errno) {
  65                         case EINTR:
  66                         case EAGAIN:
  67                                 break;
  68                         default:
  69                                 goto disconnect;
  70                         }
  71                         break;
  72                 }
  73
  74                 cl->txq_ofs += written;
  75                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
  76                         break;
  77
  78                 ubus_msg_list_free(ubl);
  79         }
  80
  81         /* prevent further ULOOP_WRITE events if we don't have data
  82          * to send anymore */
  83         if (list_empty(&cl->tx_queue) && (events & ULOOP_WRITE))
  84                 uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
  85
  86 retry:
  87         if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
  88                 int offset = cl->pending_msg_offset;
  89                 int bytes;
  90
  91                 *pfd = -1;
  92
  93                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
  94                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
  95
  96                 if (cl->pending_msg_fd < 0) {
  97                         msghdr.msg_control = fd_buf;
  98                         msghdr.msg_controllen = cmsg->cmsg_len;
  99                 } else {
 100                         msghdr.msg_control = NULL;
 101                         msghdr.msg_controllen = 0;
 102                 }
 103
 104                 bytes = recvmsg(sock->fd, &msghdr, 0);
 105                 if (bytes < 0)
 106                         goto out;
 107
 108                 if (*pfd >= 0)
 109                         cl->pending_msg_fd = *pfd;
 110
 111                 cl->pending_msg_offset += bytes;
 112                 if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
 113                         goto out;
 114
 115                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
 116                         goto disconnect;
 117
 118                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
 119                 if (!cl->pending_msg)
 120                         goto disconnect;
 121
 122                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
 123                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
 124
 125                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
 126                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
 127         }
 128
 129         ub = cl->pending_msg;
 130         if (ub) {
 131                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
 132                 int len = blob_raw_len(ub->data) - offset;
 133                 int bytes = 0;
 134
 135                 if (len > 0) {
 136                         bytes = read(sock->fd, (char *) ub->data + offset, len);
 137                         if (bytes <= 0)
 138                                 goto out;
 139                 }
 140
 141                 if (bytes < len) {
 142                         cl->pending_msg_offset += bytes;
 143                         goto out;
 144                 }
 145
 146                 /* accept message */
 147                 ub->fd = cl->pending_msg_fd;
 148                 cl->pending_msg_fd = -1;
 149                 cl->pending_msg_offset = 0;
 150                 cl->pending_msg = NULL;
 151                 ubusd_monitor_message(cl, ub, false);
 152                 ubusd_proto_receive_message(cl, ub);
 153                 goto retry;
 154         }
 155
 156 out:
 157         if (!sock->eof || !list_empty(&cl->tx_queue))
 158                 return;
 159
 160 disconnect:
 161         handle_client_disconnect(cl);
 162 }
 163
 164 static bool get_next_connection(int fd)
 165 {
 166         struct ubus_client *cl;
 167         int client_fd;
 168
 169         client_fd = accept(fd, NULL, 0);
 170         if (client_fd < 0) {
 171                 switch (errno) {
 172                 case ECONNABORTED:
 173                 case EINTR:
 174                         return true;
 175                 default:
 176                         return false;
 177                 }
 178         }
 179
 180         cl = ubusd_proto_new_client(client_fd, client_cb);
 181         if (cl)
 182                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 183         else
 184                 close(client_fd);
 185
 186         return true;
 187 }
 188
 189 static void server_cb(struct uloop_fd *fd, unsigned int events)
 190 {
 191         bool next;
 192
 193         do {
 194                 next = get_next_connection(fd->fd);
 195         } while (next);
 196 }
 197
 198 static struct uloop_fd server_fd = {
 199         .cb = server_cb,
 200 };
 201
 202 static int usage(const char *progname)
 203 {
 204         fprintf(stderr, "Usage: %s [<options>]\n"
 205                 "Options: \n"
 206                 "  -A <path>:           Set the path to ACL files\n"
 207                 "  -s <socket>:         Set the unix domain socket to listen on\n"
 208                 "\n", progname);
 209         return 1;
 210 }
 211
 212 static void sighup_handler(int sig)
 213 {
 214         ubusd_acl_load();
 215 }
 216
 217 int main(int argc, char **argv)
 218 {
 219         const char *ubus_socket = UBUS_UNIX_SOCKET;
 220         int ret = 0;
 221         int ch;
 222
 223         signal(SIGPIPE, SIG_IGN);
 224         signal(SIGHUP, sighup_handler);
 225
 226         openlog("ubusd", LOG_PID, LOG_DAEMON);
 227         uloop_init();
 228
 229         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
 230                 switch (ch) {
 231                 case 's':
 232                         ubus_socket = optarg;
 233                         break;
 234                 case 'A':
 235                         ubusd_acl_dir = optarg;
 236                         break;
 237                 default:
 238                         return usage(argv[0]);
 239                 }
 240         }
 241
 242         unlink(ubus_socket);
 243         umask(0111);
 244         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
 245         if (server_fd.fd < 0) {
 246                 perror("usock");
 247                 ret = -1;
 248                 goto out;
 249         }
 250         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 251         ubusd_acl_load();
 252
 253         uloop_run();
 254         unlink(ubus_socket);
 255
 256 out:
 257         uloop_done();
 258         return ret;
 259 }