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
  37 #include "defs.h"
  38
  39 static void server_connection(int fd);
  40 static void service_packet_loop(int fd);
  41 static void server_chld_exit(int signo);
  42 static int nconnects;
  43
  44 void
  45 doServer(void)
  46 {
  47     tag_t tag;
  48
  49     /*
  50      * Listen on one or more UDP and TCP addresses, fork for each one.
  51      */
  52     signal(SIGCHLD, SIG_IGN);
  53     for (tag = AddrBase; tag; tag = tag->next) {
  54         struct sockaddr_in sain;
  55         const char *host;
  56         int lfd;
  57         int fd;
  58         int on = 1;
  59
  60         bzero(&sain, sizeof(sain));
  61         if (tag->name == NULL) {
  62             sain.sin_addr.s_addr = INADDR_ANY;
  63             host = "<any>";
  64         } else {
  65             if (inet_aton(tag->name, &sain.sin_addr) == 0) {
  66                 struct hostent *hp;
  67                 if ((hp = gethostbyname2(tag->name, AF_INET)) == NULL) {
  68                     fprintf(stderr, "Unable to resolve %s\n", tag->name);
  69                     exit(1);
  70                 }
  71                 bcopy(hp->h_addr_list[0], &sain.sin_addr, hp->h_length);
  72                 host = strdup(hp->h_name);
  73                 endhostent();
  74             } else {
  75                 host = strdup(tag->name);
  76             }
  77         }
  78         sain.sin_port = htons(257);
  79         sain.sin_len = sizeof(sain);
  80         sain.sin_family = AF_INET;
  81         fflush(stdout);
  82         if (fork() == 0) {
  83             if ((lfd = socket(AF_INET, SOCK_STREAM, PF_UNSPEC)) < 0) {
  84                 fprintf(stderr, "%s: socket: %s\n", host, strerror(errno));
  85                 exit(1);
  86             }
  87             setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
  88             if (bind(lfd, (void *)&sain, sizeof(sain)) < 0) {
  89                 fprintf(stderr, "%s: bind: %s\n", host, strerror(errno));
  90                 exit(1);
  91             }
  92             if (listen(lfd, 20) < 0) {
  93                 fprintf(stderr, "%s: listen: %s\n", host, strerror(errno));
  94                 exit(1);
  95             }
  96             signal(SIGCHLD, server_chld_exit);
  97             for (;;) {
  98                 socklen_t slen = sizeof(sain);
  99                 fd = accept(lfd, (void *)&sain, &slen);
 100                 if (fd < 0) {
 101                     if (errno != EINTR)
 102                         break;
 103                     continue;
 104                 }
 105                 ++nconnects; /* XXX sigblock/sigsetmask */
 106                 if (fork() == 0) {
 107                     close(lfd);
 108                     server_connection(fd);
 109                     exit(0);
 110                 }
 111                 close(fd);
 112             }
 113             exit(0);
 114         }
 115         if (fork() == 0) {
 116             if ((lfd = socket(AF_INET, SOCK_DGRAM, PF_UNSPEC)) < 0) {
 117                 fprintf(stderr, "%s: socket: %s\n", host, strerror(errno));
 118                 exit(1);
 119             }
 120             if (bind(lfd, (void *)&sain, sizeof(sain)) < 0) {
 121                 fprintf(stderr, "%s: bind: %s\n", host, strerror(errno));
 122                 exit(1);
 123             }
 124             service_packet_loop(lfd);
 125             exit(1);
 126         }
 127     }
 128     while (wait(NULL) > 0 || errno != EINTR)
 129         ;
 130 }
 131
 132 static
 133 void
 134 server_chld_exit(int signo __unused)
 135 {
 136     while (wait3(NULL, WNOHANG, NULL) > 0)
 137         --nconnects;
 138 }
 139
 140 static
 141 void
 142 server_connection(int fd)
 143 {
 144     FILE *fi;
 145     FILE *fo;
 146     char buf[256];
 147     char *scan;
 148     const char *cmd;
 149     const char *name;
 150
 151     fi = fdopen(fd, "r");
 152     fo = fdopen(dup(fd), "w");
 153
 154     if (gethostname(buf, sizeof(buf)) == 0) {
 155         fprintf(fo, "108 HELLO SERVER=%s\r\n", buf);
 156     } else {
 157         fprintf(fo, "108 HELLO\r\n");
 158     }
 159     fflush(fo);
 160
 161     while (fgets(buf, sizeof(buf), fi) != NULL) {
 162         scan = buf;
 163         cmd = parse_str(&scan, PAS_ALPHA);
 164         if (cmd == NULL) {
 165             fprintf(fo, "502 Illegal Command String\r\n");
 166         } else if (strcasecmp(cmd, "VAR") == 0) {
 167             fprintf(fo, "100 OK\r\n");
 168         } else if (strcasecmp(cmd, "TAG") == 0) {
 169             if ((name = parse_str(&scan, PAS_ALPHA|PAS_NUMERIC)) == NULL) {
 170                 fprintf(fo, "401 Illegal Tag\r\n");
 171             } else {
 172                 char *path = NULL;
 173                 FILE *fp;
 174                 asprintf(&path, "%s/%s.sh", TagDir, name);
 175                 if ((fp = fopen(path, "r")) == NULL) {
 176                     fprintf(fo, "402 '%s' Not Found\r\n", name);
 177                 } else {
 178                     size_t bytes;
 179                     size_t n;
 180                     int error = 0;
 181
 182                     fseek(fp, 0L, 2);
 183                     bytes = (size_t)ftell(fp);
 184                     fseek(fp, 0L, 0);
 185                     fprintf(fo, "201 SIZE=%d\r\n", (int)bytes);
 186                     while (bytes > 0) {
 187                         n = (bytes > sizeof(buf)) ? sizeof(buf) : bytes;
 188                         n = fread(buf, 1, n, fp);
 189                         if (n <= 0) {
 190                             error = 1;
 191                             break;
 192                         }
 193                         if (fwrite(buf, 1, n, fo) != n) {
 194                             error = 1;
 195                             break;
 196                         }
 197                         bytes -= n;
 198                     }
 199                     fclose(fp);
 200                     if (bytes > 0 && ferror(fo) == 0) {
 201                         bzero(buf, sizeof(buf));
 202                         while (bytes > 0) {
 203                             n = (bytes > sizeof(buf)) ? sizeof(buf) : bytes;
 204                             if (fwrite(buf, 1, n, fo) != n)
 205                                 break;
 206                             bytes -= n;
 207                         }
 208                     }
 209                     fprintf(fo, "202 ERROR=%d\r\n", error);
 210                 }
 211                 free(path);
 212             }
 213         } else if (strcasecmp(cmd, "IDLE") == 0) {
 214             if ((name = parse_str(&scan, PAS_ANY)) == NULL) {
 215                 fprintf(fo, "401 Illegal String\r\n");
 216             } else {
 217                 fprintf(fo, "109 %s\r\n", name);
 218             }
 219         } else if (strcasecmp(cmd, "QUIT") == 0) {
 220             fprintf(fo, "409 Bye!\r\n");
 221             break;
 222         } else {
 223             fprintf(fo, "501 Unknown Command\r\n");
 224         }
 225         fflush(fo);
 226     }
 227     fclose(fi);
 228     fclose(fo);
 229 }
 230
 231 /*
 232  * UDP packet loop.  For now just handle one request per packet.  Note that
 233  * since the protocol is designed to be used in a broadcast environment,
 234  * we only respond when we have something to contribute.
 235  */
 236 static
 237 void
 238 service_packet_loop(int fd)
 239 {
 240     struct sockaddr_in sain;
 241     char ibuf[256+1];
 242     char obuf[256+1];
 243     socklen_t sain_len;
 244     int n;
 245     char *scan;
 246     const char *cmd;
 247     const char *name;
 248
 249     for (;;) {
 250         sain_len = sizeof(sain);
 251         n = recvfrom(fd, ibuf, sizeof(ibuf) - 1, 0, (void *)&sain, &sain_len);
 252         if (n < 0) {
 253             if (errno == EINTR)
 254                 continue;
 255             break;
 256         }
 257         ibuf[n] = 0;
 258         n = 0;
 259         scan = ibuf;
 260         cmd = parse_str(&scan, PAS_ALPHA);
 261         if (cmd == NULL) {
 262             ;
 263         } else if (strcasecmp(cmd, "TAG") == 0) {
 264             if ((name = parse_str(&scan, PAS_ALPHA|PAS_NUMERIC)) != NULL) {
 265                 char *path = NULL;
 266                 struct stat st;
 267                 asprintf(&path, "%s/%s.sh", TagDir, name);
 268                 if (stat(path, &st) == 0) {
 269                     snprintf(obuf, sizeof(obuf), "101 TAG=%s\r\n", name);
 270                     n = strlen(obuf);
 271                 }
 272                 free(path);
 273             }
 274         }
 275         if (n)
 276             sendto(fd, obuf, n, 0, (void *)&sain, sain_len);
 277     }
 278 }
 279