sbin/rconfig/server.c

   1 /*
   2  * RCONFIG/SERVER.C
   3  *
   4  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to The DragonFly Project
   7  * by Matthew Dillon <dillon@backplane.com>
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  * 3. Neither the name of The DragonFly Project nor the names of its
  20  *    contributors may be used to endorse or promote products derived
  21  *    from this software without specific, prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  26  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  27  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  28  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  29  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  30  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  31  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  32  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  33  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * $DragonFly: src/sbin/rconfig/server.c,v 1.3 2005/04/02 22:15:20 dillon Exp $
  37  */
  38
  39 #include "defs.h"
  40
  41 static void server_connection(int fd);
  42 static void service_packet_loop(int fd);
  43 static void server_chld_exit(int signo);
  44 static int nconnects;
  45
  46 void
  47 doServer(void)
  48 {
  49     tag_t tag;
  50
  51     /*
  52      * Listen on one or more UDP and TCP addresses, fork for each one.
  53      */
  54     signal(SIGCHLD, SIG_IGN);
  55     for (tag = AddrBase; tag; tag = tag->next) {
  56         struct sockaddr_in sain;
  57         const char *host;
  58         int lfd;
  59         int fd;
  60         int on = 1;
  61
  62         bzero(&sain, sizeof(sain));
  63         if (tag->name == NULL) {
  64             sain.sin_addr.s_addr = INADDR_ANY;
  65             host = "<any>";
  66         } else {
  67             if (inet_aton(tag->name, &sain.sin_addr) == 0) {
  68                 struct hostent *hp;
  69                 if ((hp = gethostbyname2(tag->name, AF_INET)) == NULL) {
  70                     fprintf(stderr, "Unable to resolve %s\n", tag->name);
  71                     exit(1);
  72                 }
  73                 bcopy(hp->h_addr_list[0], &sain.sin_addr, hp->h_length);
  74                 host = strdup(hp->h_name);
  75                 endhostent();
  76             } else {
  77                 host = strdup(tag->name);
  78             }
  79         }
  80         sain.sin_port = htons(257);
  81         sain.sin_len = sizeof(sain);
  82         sain.sin_family = AF_INET;
  83         fflush(stdout);
  84         if (fork() == 0) {
  85             if ((lfd = socket(AF_INET, SOCK_STREAM, PF_UNSPEC)) < 0) {
  86                 fprintf(stderr, "%s: socket: %s\n", host, strerror(errno));
  87                 exit(1);
  88             }
  89             setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
  90             if (bind(lfd, (void *)&sain, sizeof(sain)) < 0) {
  91                 fprintf(stderr, "%s: bind: %s\n", host, strerror(errno));
  92                 exit(1);
  93             }
  94             if (listen(lfd, 20) < 0) {
  95                 fprintf(stderr, "%s: listen: %s\n", host, strerror(errno));
  96                 exit(1);
  97             }
  98             signal(SIGCHLD, server_chld_exit);
  99             for (;;) {
 100                 int slen = sizeof(sain);
 101                 fd = accept(lfd, (void *)&sain, &slen);
 102                 if (fd < 0) {
 103                     if (errno != EINTR)
 104                         break;
 105                     continue;
 106                 }
 107                 ++nconnects; /* XXX sigblock/sigsetmask */
 108                 if (fork() == 0) {
 109                     close(lfd);
 110                     server_connection(fd);
 111                     exit(0);
 112                 }
 113                 close(fd);
 114             }
 115             exit(0);
 116         }
 117         if (fork() == 0) {
 118             if ((lfd = socket(AF_INET, SOCK_DGRAM, PF_UNSPEC)) < 0) {
 119                 fprintf(stderr, "%s: socket: %s\n", host, strerror(errno));
 120                 exit(1);
 121             }
 122             if (bind(lfd, (void *)&sain, sizeof(sain)) < 0) {
 123                 fprintf(stderr, "%s: bind: %s\n", host, strerror(errno));
 124                 exit(1);
 125             }
 126             service_packet_loop(lfd);
 127             exit(1);
 128         }
 129     }
 130     while (wait(NULL) > 0 || errno != EINTR)
 131         ;
 132 }
 133
 134 static
 135 void
 136 server_chld_exit(int signo __unused)
 137 {
 138     while (wait3(NULL, WNOHANG, NULL) > 0)
 139         --nconnects;
 140 }
 141
 142 static
 143 void
 144 server_connection(int fd)
 145 {
 146     FILE *fi;
 147     FILE *fo;
 148     char buf[256];
 149     char *scan;
 150     const char *cmd;
 151     const char *name;
 152
 153     fi = fdopen(fd, "r");
 154     fo = fdopen(dup(fd), "w");
 155
 156     if (gethostname(buf, sizeof(buf)) == 0) {
 157         fprintf(fo, "108 HELLO SERVER=%s\r\n", buf);
 158     } else {
 159         fprintf(fo, "108 HELLO\r\n", buf);
 160     }
 161     fflush(fo);
 162
 163     while (fgets(buf, sizeof(buf), fi) != NULL) {
 164         scan = buf;
 165         cmd = parse_str(&scan, PAS_ALPHA);
 166         if (cmd == NULL) {
 167             fprintf(fo, "502 Illegal Command String\r\n");
 168         } else if (strcasecmp(cmd, "VAR") == 0) {
 169             fprintf(fo, "100 OK\r\n");
 170         } else if (strcasecmp(cmd, "TAG") == 0) {
 171             if ((name = parse_str(&scan, PAS_ALPHA|PAS_NUMERIC)) == NULL) {
 172                 fprintf(fo, "401 Illegal Tag\r\n");
 173             } else {
 174                 char *path = NULL;
 175                 FILE *fp;
 176                 asprintf(&path, "%s/%s.sh", TagDir, name);
 177                 if ((fp = fopen(path, "r")) == NULL) {
 178                     fprintf(fo, "402 '%s' Not Found\r\n", name);
 179                 } else {
 180                     size_t bytes;
 181                     size_t n;
 182                     int error = 0;
 183
 184                     fseek(fp, 0L, 2);
 185                     bytes = (size_t)ftell(fp);
 186                     fseek(fp, 0L, 0);
 187                     fprintf(fo, "201 SIZE=%d\r\n", (int)bytes);
 188                     while (bytes > 0) {
 189                         n = (bytes > sizeof(buf)) ? sizeof(buf) : bytes;
 190                         n = fread(buf, 1, n, fp);
 191                         if (n <= 0) {
 192                             error = 1;
 193                             break;
 194                         }
 195                         if (fwrite(buf, 1, n, fo) != n) {
 196                             error = 1;
 197                             break;
 198                         }
 199                         bytes -= n;
 200                     }
 201                     fclose(fp);
 202                     if (bytes > 0 && ferror(fo) == 0) {
 203                         bzero(buf, sizeof(buf));
 204                         while (bytes > 0) {
 205                             n = (bytes > sizeof(buf)) ? sizeof(buf) : bytes;
 206                             if (fwrite(buf, 1, n, fo) != n)
 207                                 break;
 208                             bytes -= n;
 209                         }
 210                     }
 211                     fprintf(fo, "202 ERROR=%d\r\n", error);
 212                 }
 213                 free(path);
 214             }
 215         } else if (strcasecmp(cmd, "IDLE") == 0) {
 216             if ((name = parse_str(&scan, PAS_ANY)) == NULL) {
 217                 fprintf(fo, "401 Illegal String\r\n");
 218             } else {
 219                 fprintf(fo, "109 %s\r\n", name);
 220             }
 221         } else if (strcasecmp(cmd, "QUIT") == 0) {
 222             fprintf(fo, "409 Bye!\r\n");
 223             break;
 224         } else {
 225             fprintf(fo, "501 Unknown Command\r\n");
 226         }
 227         fflush(fo);
 228     }
 229     fclose(fi);
 230     fclose(fo);
 231 }
 232
 233 /*
 234  * UDP packet loop.  For now just handle one request per packet.  Note that
 235  * since the protocol is designed to be used in a broadcast environment,
 236  * we only respond when we have something to contribute.
 237  */
 238 static
 239 void
 240 service_packet_loop(int fd)
 241 {
 242     struct sockaddr_in sain;
 243     char ibuf[256+1];
 244     char obuf[256+1];
 245     int sain_len;
 246     int n;
 247     char *scan;
 248     const char *cmd;
 249     const char *name;
 250
 251     for (;;) {
 252         sain_len = sizeof(sain);
 253         n = recvfrom(fd, ibuf, sizeof(ibuf) - 1, 0, (void *)&sain, &sain_len);
 254         if (n < 0) {
 255             if (errno == EINTR)
 256                 continue;
 257             break;
 258         }
 259         ibuf[n] = 0;
 260         n = 0;
 261         scan = ibuf;
 262         cmd = parse_str(&scan, PAS_ALPHA);
 263         if (cmd == NULL) {
 264             ;
 265         } else if (strcasecmp(cmd, "TAG") == 0) {
 266             if ((name = parse_str(&scan, PAS_ALPHA|PAS_NUMERIC)) != NULL) {
 267                 char *path = NULL;
 268                 struct stat st;
 269                 asprintf(&path, "%s/%s.sh", TagDir, name);
 270                 if (stat(path, &st) == 0) {
 271                     snprintf(obuf, sizeof(obuf), "101 TAG=%s\r\n", name);
 272                     n = strlen(obuf);
 273                 }
 274                 free(path);
 275             }
 276         }
 277         if (n)
 278             sendto(fd, obuf, n, 0, (void *)&sain, sain_len);
 279     }
 280 }
 281