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 struct ubus_msg_buf *ubus_msg_head(struct ubus_client *cl)
  19 {
  20         return cl->tx_queue[cl->txq_cur];
  21 }
  22
  23 static void ubus_msg_dequeue(struct ubus_client *cl)
  24 {
  25         struct ubus_msg_buf *ub = ubus_msg_head(cl);
  26
  27         if (!ub)
  28                 return;
  29
  30         ubus_msg_free(ub);
  31         cl->txq_ofs = 0;
  32         cl->tx_queue[cl->txq_cur] = NULL;
  33         cl->txq_cur = (cl->txq_cur + 1) % ARRAY_SIZE(cl->tx_queue);
  34 }
  35
  36 static void handle_client_disconnect(struct ubus_client *cl)
  37 {
  38         while (ubus_msg_head(cl))
  39                 ubus_msg_dequeue(cl);
  40
  41         ubusd_monitor_disconnect(cl);
  42         ubusd_proto_free_client(cl);
  43         if (cl->pending_msg_fd >= 0)
  44                 close(cl->pending_msg_fd);
  45         uloop_fd_delete(&cl->sock);
  46         close(cl->sock.fd);
  47         free(cl);
  48 }
  49
  50 static void client_cb(struct uloop_fd *sock, unsigned int events)
  51 {
  52         struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
  53         uint8_t fd_buf[CMSG_SPACE(sizeof(int))] = { 0 };
  54         struct msghdr msghdr = { 0 };
  55         struct ubus_msg_buf *ub;
  56         static struct iovec iov;
  57         struct cmsghdr *cmsg;
  58         int *pfd;
  59
  60         msghdr.msg_iov = &iov,
  61         msghdr.msg_iovlen = 1,
  62         msghdr.msg_control = fd_buf;
  63         msghdr.msg_controllen = sizeof(fd_buf);
  64
  65         cmsg = CMSG_FIRSTHDR(&msghdr);
  66         cmsg->cmsg_type = SCM_RIGHTS;
  67         cmsg->cmsg_level = SOL_SOCKET;
  68         cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  69
  70         pfd = (int *) CMSG_DATA(cmsg);
  71         msghdr.msg_controllen = cmsg->cmsg_len;
  72
  73         /* first try to tx more pending data */
  74         while ((ub = ubus_msg_head(cl))) {
  75                 ssize_t written;
  76
  77                 written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
  78                 if (written < 0) {
  79                         switch(errno) {
  80                         case EINTR:
  81                         case EAGAIN:
  82                                 break;
  83                         default:
  84                                 goto disconnect;
  85                         }
  86                         break;
  87                 }
  88
  89                 cl->txq_ofs += written;
  90                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
  91                         break;
  92
  93                 ubus_msg_dequeue(cl);
  94         }
  95
  96         /* prevent further ULOOP_WRITE events if we don't have data
  97          * to send anymore */
  98         if (!ubus_msg_head(cl) && (events & ULOOP_WRITE))
  99                 uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 100
 101 retry:
 102         if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
 103                 int offset = cl->pending_msg_offset;
 104                 int bytes;
 105
 106                 *pfd = -1;
 107
 108                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
 109                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
 110
 111                 if (cl->pending_msg_fd < 0) {
 112                         msghdr.msg_control = fd_buf;
 113                         msghdr.msg_controllen = cmsg->cmsg_len;
 114                 } else {
 115                         msghdr.msg_control = NULL;
 116                         msghdr.msg_controllen = 0;
 117                 }
 118
 119                 bytes = recvmsg(sock->fd, &msghdr, 0);
 120                 if (bytes < 0)
 121                         goto out;
 122
 123                 if (*pfd >= 0)
 124                         cl->pending_msg_fd = *pfd;
 125
 126                 cl->pending_msg_offset += bytes;
 127                 if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
 128                         goto out;
 129
 130                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
 131                         goto disconnect;
 132
 133                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
 134                 if (!cl->pending_msg)
 135                         goto disconnect;
 136
 137                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
 138                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
 139
 140                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
 141                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
 142         }
 143
 144         ub = cl->pending_msg;
 145         if (ub) {
 146                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
 147                 int len = blob_raw_len(ub->data) - offset;
 148                 int bytes = 0;
 149
 150                 if (len > 0) {
 151                         bytes = read(sock->fd, (char *) ub->data + offset, len);
 152                         if (bytes <= 0)
 153                                 goto out;
 154                 }
 155
 156                 if (bytes < len) {
 157                         cl->pending_msg_offset += bytes;
 158                         goto out;
 159                 }
 160
 161                 /* accept message */
 162                 ub->fd = cl->pending_msg_fd;
 163                 cl->pending_msg_fd = -1;
 164                 cl->pending_msg_offset = 0;
 165                 cl->pending_msg = NULL;
 166                 ubusd_monitor_message(cl, ub, false);
 167                 ubusd_proto_receive_message(cl, ub);
 168                 goto retry;
 169         }
 170
 171 out:
 172         if (!sock->eof || ubus_msg_head(cl))
 173                 return;
 174
 175 disconnect:
 176         handle_client_disconnect(cl);
 177 }
 178
 179 static bool get_next_connection(int fd)
 180 {
 181         struct ubus_client *cl;
 182         int client_fd;
 183
 184         client_fd = accept(fd, NULL, 0);
 185         if (client_fd < 0) {
 186                 switch (errno) {
 187                 case ECONNABORTED:
 188                 case EINTR:
 189                         return true;
 190                 default:
 191                         return false;
 192                 }
 193         }
 194
 195         cl = ubusd_proto_new_client(client_fd, client_cb);
 196         if (cl)
 197                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 198         else
 199                 close(client_fd);
 200
 201         return true;
 202 }
 203
 204 static void server_cb(struct uloop_fd *fd, unsigned int events)
 205 {
 206         bool next;
 207
 208         do {
 209                 next = get_next_connection(fd->fd);
 210         } while (next);
 211 }
 212
 213 static struct uloop_fd server_fd = {
 214         .cb = server_cb,
 215 };
 216
 217 static int usage(const char *progname)
 218 {
 219         fprintf(stderr, "Usage: %s [<options>]\n"
 220                 "Options: \n"
 221                 "  -A <path>:           Set the path to ACL files\n"
 222                 "  -s <socket>:         Set the unix domain socket to listen on\n"
 223                 "\n", progname);
 224         return 1;
 225 }
 226
 227 static void sighup_handler(int sig)
 228 {
 229         ubusd_acl_load();
 230 }
 231
 232 int main(int argc, char **argv)
 233 {
 234         const char *ubus_socket = UBUS_UNIX_SOCKET;
 235         int ret = 0;
 236         int ch;
 237
 238         signal(SIGPIPE, SIG_IGN);
 239         signal(SIGHUP, sighup_handler);
 240
 241         openlog("ubusd", LOG_PID, LOG_DAEMON);
 242         uloop_init();
 243
 244         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
 245                 switch (ch) {
 246                 case 's':
 247                         ubus_socket = optarg;
 248                         break;
 249                 case 'A':
 250                         ubusd_acl_dir = optarg;
 251                         break;
 252                 default:
 253                         return usage(argv[0]);
 254                 }
 255         }
 256
 257         unlink(ubus_socket);
 258         umask(0111);
 259         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
 260         if (server_fd.fd < 0) {
 261                 perror("usock");
 262                 ret = -1;
 263                 goto out;
 264         }
 265         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 266         ubusd_acl_load();
 267
 268         uloop_run();
 269         unlink(ubus_socket);
 270
 271 out:
 272         uloop_done();
 273         return ret;
 274 }