Documentation/connector/ucon.c

   1 /*
   2  *      ucon.c
   3  *
   4  * Copyright (c) 2004+ Evgeniy Polyakov <johnpol@2ka.mipt.ru>
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <asm/types.h>
  23
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <sys/poll.h>
  27
  28 #include <linux/netlink.h>
  29 #include <linux/rtnetlink.h>
  30
  31 #include <arpa/inet.h>
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <unistd.h>
  36 #include <string.h>
  37 #include <errno.h>
  38 #include <time.h>
  39
  40 #include <linux/connector.h>
  41
  42 #define DEBUG
  43 #define NETLINK_CONNECTOR       11
  44
  45 #ifdef DEBUG
  46 #define ulog(f, a...) fprintf(stdout, f, ##a)
  47 #else
  48 #define ulog(f, a...) do {} while (0)
  49 #endif
  50
  51 static int need_exit;
  52 static __u32 seq;
  53
  54 static int netlink_send(int s, struct cn_msg *msg)
  55 {
  56         struct nlmsghdr *nlh;
  57         unsigned int size;
  58         int err;
  59         char buf[128];
  60         struct cn_msg *m;
  61
  62         size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
  63
  64         nlh = (struct nlmsghdr *)buf;
  65         nlh->nlmsg_seq = seq++;
  66         nlh->nlmsg_pid = getpid();
  67         nlh->nlmsg_type = NLMSG_DONE;
  68         nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
  69         nlh->nlmsg_flags = 0;
  70
  71         m = NLMSG_DATA(nlh);
  72 #if 0
  73         ulog("%s: [%08x.%08x] len=%u, seq=%u, ack=%u.\n",
  74                __func__, msg->id.idx, msg->id.val, msg->len, msg->seq, msg->ack);
  75 #endif
  76         memcpy(m, msg, sizeof(*m) + msg->len);
  77
  78         err = send(s, nlh, size, 0);
  79         if (err == -1)
  80                 ulog("Failed to send: %s [%d].\n",
  81                         strerror(errno), errno);
  82
  83         return err;
  84 }
  85
  86 int main(int argc, char *argv[])
  87 {
  88         int s;
  89         char buf[1024];
  90         int len;
  91         struct nlmsghdr *reply;
  92         struct sockaddr_nl l_local;
  93         struct cn_msg *data;
  94         FILE *out;
  95         time_t tm;
  96         struct pollfd pfd;
  97
  98         if (argc < 2)
  99                 out = stdout;
 100         else {
 101                 out = fopen(argv[1], "a+");
 102                 if (!out) {
 103                         ulog("Unable to open %s for writing: %s\n",
 104                                 argv[1], strerror(errno));
 105                         out = stdout;
 106                 }
 107         }
 108
 109         memset(buf, 0, sizeof(buf));
 110
 111         s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
 112         if (s == -1) {
 113                 perror("socket");
 114                 return -1;
 115         }
 116
 117         l_local.nl_family = AF_NETLINK;
 118         l_local.nl_groups = 0x123; /* bitmask of requested groups */
 119         l_local.nl_pid = 0;
 120
 121         if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
 122                 perror("bind");
 123                 close(s);
 124                 return -1;
 125         }
 126
 127 #if 0
 128         {
 129                 int on = 0x57; /* Additional group number */
 130                 setsockopt(s, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &on, sizeof(on));
 131         }
 132 #endif
 133         if (0) {
 134                 int i, j;
 135
 136                 memset(buf, 0, sizeof(buf));
 137
 138                 data = (struct cn_msg *)buf;
 139
 140                 data->id.idx = 0x123;
 141                 data->id.val = 0x456;
 142                 data->seq = seq++;
 143                 data->ack = 0;
 144                 data->len = 0;
 145
 146                 for (j=0; j<10; ++j) {
 147                         for (i=0; i<1000; ++i) {
 148                                 len = netlink_send(s, data);
 149                         }
 150
 151                         ulog("%d messages have been sent to %08x.%08x.\n", i, data->id.idx, data->id.val);
 152                 }
 153
 154                 return 0;
 155         }
 156
 157
 158         pfd.fd = s;
 159
 160         while (!need_exit) {
 161                 pfd.events = POLLIN;
 162                 pfd.revents = 0;
 163                 switch (poll(&pfd, 1, -1)) {
 164                         case 0:
 165                                 need_exit = 1;
 166                                 break;
 167                         case -1:
 168                                 if (errno != EINTR) {
 169                                         need_exit = 1;
 170                                         break;
 171                                 }
 172                                 continue;
 173                 }
 174                 if (need_exit)
 175                         break;
 176
 177                 memset(buf, 0, sizeof(buf));
 178                 len = recv(s, buf, sizeof(buf), 0);
 179                 if (len == -1) {
 180                         perror("recv buf");
 181                         close(s);
 182                         return -1;
 183                 }
 184                 reply = (struct nlmsghdr *)buf;
 185
 186                 switch (reply->nlmsg_type) {
 187                 case NLMSG_ERROR:
 188                         fprintf(out, "Error message received.\n");
 189                         fflush(out);
 190                         break;
 191                 case NLMSG_DONE:
 192                         data = (struct cn_msg *)NLMSG_DATA(reply);
 193
 194                         time(&tm);
 195                         fprintf(out, "%.24s : [%x.%x] [%08u.%08u].\n",
 196                                 ctime(&tm), data->id.idx, data->id.val, data->seq, data->ack);
 197                         fflush(out);
 198                         break;
 199                 default:
 200                         break;
 201                 }
 202         }
 203
 204         close(s);
 205         return 0;
 206 }