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                 cl->txq_len -= written;
  76                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
  77                         break;
  78
  79                 cl->txq_ofs = 0;
  80                 ubus_msg_list_free(ubl);
  81         }
  82
  83         /* prevent further ULOOP_WRITE events if we don't have data
  84          * to send anymore */
  85         if (list_empty(&cl->tx_queue) && (events & ULOOP_WRITE))
  86                 uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
  87
  88 retry:
  89         if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
  90                 int offset = cl->pending_msg_offset;
  91                 int bytes;
  92
  93                 *pfd = -1;
  94
  95                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
  96                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
  97
  98                 if (cl->pending_msg_fd < 0) {
  99                         msghdr.msg_control = fd_buf;
 100                         msghdr.msg_controllen = cmsg->cmsg_len;
 101                 } else {
 102                         msghdr.msg_control = NULL;
 103                         msghdr.msg_controllen = 0;
 104                 }
 105
 106                 bytes = recvmsg(sock->fd, &msghdr, 0);
 107                 if (bytes < 0)
 108                         goto out;
 109
 110                 if (*pfd >= 0)
 111                         cl->pending_msg_fd = *pfd;
 112
 113                 cl->pending_msg_offset += bytes;
 114                 if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
 115                         goto out;
 116
 117                 if (blob_raw_len(&cl->hdrbuf.data) < sizeof(struct blob_attr))
 118                         goto disconnect;
 119                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
 120                         goto disconnect;
 121
 122                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
 123                 if (!cl->pending_msg)
 124                         goto disconnect;
 125
 126                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
 127                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
 128
 129                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
 130                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
 131         }
 132
 133         ub = cl->pending_msg;
 134         if (ub) {
 135                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
 136                 int len = blob_raw_len(ub->data) - offset;
 137                 int bytes = 0;
 138
 139                 if (len > 0) {
 140                         bytes = read(sock->fd, (char *) ub->data + offset, len);
 141                         if (bytes <= 0)
 142                                 goto out;
 143                 }
 144
 145                 if (bytes < len) {
 146                         cl->pending_msg_offset += bytes;
 147                         goto out;
 148                 }
 149
 150                 /* accept message */
 151                 ub->fd = cl->pending_msg_fd;
 152                 cl->pending_msg_fd = -1;
 153                 cl->pending_msg_offset = 0;
 154                 cl->pending_msg = NULL;
 155                 ubusd_monitor_message(cl, ub, false);
 156                 ubusd_proto_receive_message(cl, ub);
 157                 goto retry;
 158         }
 159
 160 out:
 161         if (!sock->eof || !list_empty(&cl->tx_queue))
 162                 return;
 163
 164 disconnect:
 165         handle_client_disconnect(cl);
 166 }
 167
 168 static bool get_next_connection(int fd)
 169 {
 170         struct ubus_client *cl;
 171         int client_fd;
 172
 173         client_fd = accept(fd, NULL, 0);
 174         if (client_fd < 0) {
 175                 switch (errno) {
 176                 case ECONNABORTED:
 177                 case EINTR:
 178                         return true;
 179                 default:
 180                         return false;
 181                 }
 182         }
 183
 184         cl = ubusd_proto_new_client(client_fd, client_cb);
 185         if (cl)
 186                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 187         else
 188                 close(client_fd);
 189
 190         return true;
 191 }
 192
 193 static void server_cb(struct uloop_fd *fd, unsigned int events)
 194 {
 195         bool next;
 196
 197         do {
 198                 next = get_next_connection(fd->fd);
 199         } while (next);
 200 }
 201
 202 static struct uloop_fd server_fd = {
 203         .cb = server_cb,
 204 };
 205
 206 static int usage(const char *progname)
 207 {
 208         fprintf(stderr, "Usage: %s [<options>]\n"
 209                 "Options: \n"
 210                 "  -A <path>:           Set the path to ACL files\n"
 211                 "  -s <socket>:         Set the unix domain socket to listen on\n"
 212                 "\n", progname);
 213         return 1;
 214 }
 215
 216 static void sighup_handler(int sig)
 217 {
 218         ubusd_acl_load();
 219 }
 220
 221 int main(int argc, char **argv)
 222 {
 223         const char *ubus_socket = UBUS_UNIX_SOCKET;
 224         int ret = 0;
 225         int ch;
 226
 227         signal(SIGPIPE, SIG_IGN);
 228         signal(SIGHUP, sighup_handler);
 229
 230         openlog("ubusd", LOG_PID, LOG_DAEMON);
 231         uloop_init();
 232
 233         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
 234                 switch (ch) {
 235                 case 's':
 236                         ubus_socket = optarg;
 237                         break;
 238                 case 'A':
 239                         ubusd_acl_dir = optarg;
 240                         break;
 241                 default:
 242                         return usage(argv[0]);
 243                 }
 244         }
 245
 246         unlink(ubus_socket);
 247         umask(0111);
 248         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
 249         if (server_fd.fd < 0) {
 250                 perror("usock");
 251                 ret = -1;
 252                 goto out;
 253         }
 254         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
 255         ubusd_acl_load();
 256
 257         uloop_run();
 258         unlink(ubus_socket);
 259
 260 out:
 261         uloop_done();
 262         return ret;
 263 }