| 1 | /* |
| 2 | Copyright (C) Andrew Tridgell 1998 |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of the GNU General Public License as published by |
| 6 | the Free Software Foundation; either version 2 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program; if not, write to the Free Software |
| 16 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 17 | */ |
| 18 | |
| 19 | /* |
| 20 | socket functions used in rsync |
| 21 | |
| 22 | */ |
| 23 | |
| 24 | #include "rsync.h" |
| 25 | |
| 26 | /* open a socket to a tcp remote host with the specified port |
| 27 | based on code from Warren */ |
| 28 | int open_socket_out(char *host, int port) |
| 29 | { |
| 30 | int type = SOCK_STREAM; |
| 31 | struct sockaddr_in sock_out; |
| 32 | int res; |
| 33 | struct hostent *hp; |
| 34 | |
| 35 | |
| 36 | res = socket(PF_INET, type, 0); |
| 37 | if (res == -1) { |
| 38 | return -1; |
| 39 | } |
| 40 | |
| 41 | hp = gethostbyname(host); |
| 42 | if (!hp) { |
| 43 | rprintf(FERROR,"unknown host: %s\n", host); |
| 44 | return -1; |
| 45 | } |
| 46 | |
| 47 | memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length); |
| 48 | sock_out.sin_port = htons(port); |
| 49 | sock_out.sin_family = PF_INET; |
| 50 | |
| 51 | if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) { |
| 52 | close(res); |
| 53 | rprintf(FERROR,"failed to connect to %s - %s\n", host, strerror(errno)); |
| 54 | return -1; |
| 55 | } |
| 56 | |
| 57 | return res; |
| 58 | } |
| 59 | |
| 60 | |
| 61 | /**************************************************************************** |
| 62 | open a socket of the specified type, port and address for incoming data |
| 63 | ****************************************************************************/ |
| 64 | static int open_socket_in(int type, int port) |
| 65 | { |
| 66 | struct hostent *hp; |
| 67 | struct sockaddr_in sock; |
| 68 | char host_name[200]; |
| 69 | int res; |
| 70 | int one=1; |
| 71 | |
| 72 | /* get my host name */ |
| 73 | if (gethostname(host_name, sizeof(host_name)) == -1) { |
| 74 | rprintf(FERROR,"gethostname failed\n"); |
| 75 | return -1; |
| 76 | } |
| 77 | |
| 78 | /* get host info */ |
| 79 | if ((hp = gethostbyname(host_name)) == 0) { |
| 80 | rprintf(FERROR,"gethostbyname: Unknown host %s\n",host_name); |
| 81 | return -1; |
| 82 | } |
| 83 | |
| 84 | bzero((char *)&sock,sizeof(sock)); |
| 85 | memcpy((char *)&sock.sin_addr,(char *)hp->h_addr, hp->h_length); |
| 86 | sock.sin_port = htons(port); |
| 87 | sock.sin_family = hp->h_addrtype; |
| 88 | sock.sin_addr.s_addr = INADDR_ANY; |
| 89 | res = socket(hp->h_addrtype, type, 0); |
| 90 | if (res == -1) { |
| 91 | rprintf(FERROR,"socket failed\n"); |
| 92 | return -1; |
| 93 | } |
| 94 | |
| 95 | setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); |
| 96 | |
| 97 | /* now we've got a socket - we need to bind it */ |
| 98 | if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) { |
| 99 | rprintf(FERROR,"bind failed on port %d\n", port); |
| 100 | close(res); |
| 101 | return -1; |
| 102 | } |
| 103 | |
| 104 | return res; |
| 105 | } |
| 106 | |
| 107 | |
| 108 | /**************************************************************************** |
| 109 | determine if a file descriptor is in fact a socket |
| 110 | ****************************************************************************/ |
| 111 | int is_a_socket(int fd) |
| 112 | { |
| 113 | int v,l; |
| 114 | l = sizeof(int); |
| 115 | return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0); |
| 116 | } |
| 117 | |
| 118 | |
| 119 | void start_accept_loop(int port, int (*fn)(int )) |
| 120 | { |
| 121 | int s; |
| 122 | |
| 123 | signal(SIGCHLD, SIG_IGN); |
| 124 | |
| 125 | /* open an incoming socket */ |
| 126 | s = open_socket_in(SOCK_STREAM, port); |
| 127 | if (s == -1) |
| 128 | exit_cleanup(1); |
| 129 | |
| 130 | /* ready to listen */ |
| 131 | if (listen(s, 5) == -1) { |
| 132 | close(s); |
| 133 | exit_cleanup(1); |
| 134 | } |
| 135 | |
| 136 | |
| 137 | /* now accept incoming connections - forking a new process |
| 138 | for each incoming connection */ |
| 139 | while (1) { |
| 140 | fd_set fds; |
| 141 | int fd; |
| 142 | struct sockaddr addr; |
| 143 | int in_addrlen = sizeof(addr); |
| 144 | |
| 145 | FD_ZERO(&fds); |
| 146 | FD_SET(s, &fds); |
| 147 | |
| 148 | if (select(s+1, &fds, NULL, NULL, NULL) != 1) { |
| 149 | continue; |
| 150 | } |
| 151 | |
| 152 | if(!FD_ISSET(s, &fds)) continue; |
| 153 | |
| 154 | fd = accept(s,&addr,&in_addrlen); |
| 155 | |
| 156 | if (fd == -1) continue; |
| 157 | |
| 158 | if (fork()==0) { |
| 159 | close(s); |
| 160 | |
| 161 | _exit(fn(fd)); |
| 162 | } |
| 163 | |
| 164 | close(fd); |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | |
| 169 | enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON}; |
| 170 | |
| 171 | struct |
| 172 | { |
| 173 | char *name; |
| 174 | int level; |
| 175 | int option; |
| 176 | int value; |
| 177 | int opttype; |
| 178 | } socket_options[] = { |
| 179 | {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL}, |
| 180 | {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL}, |
| 181 | {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL}, |
| 182 | #ifdef TCP_NODELAY |
| 183 | {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL}, |
| 184 | #endif |
| 185 | #ifdef IPTOS_LOWDELAY |
| 186 | {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON}, |
| 187 | #endif |
| 188 | #ifdef IPTOS_THROUGHPUT |
| 189 | {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON}, |
| 190 | #endif |
| 191 | #ifdef SO_SNDBUF |
| 192 | {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT}, |
| 193 | #endif |
| 194 | #ifdef SO_RCVBUF |
| 195 | {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT}, |
| 196 | #endif |
| 197 | #ifdef SO_SNDLOWAT |
| 198 | {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT}, |
| 199 | #endif |
| 200 | #ifdef SO_RCVLOWAT |
| 201 | {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT}, |
| 202 | #endif |
| 203 | #ifdef SO_SNDTIMEO |
| 204 | {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT}, |
| 205 | #endif |
| 206 | #ifdef SO_RCVTIMEO |
| 207 | {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT}, |
| 208 | #endif |
| 209 | {NULL,0,0,0,0}}; |
| 210 | |
| 211 | |
| 212 | |
| 213 | /**************************************************************************** |
| 214 | set user socket options |
| 215 | ****************************************************************************/ |
| 216 | void set_socket_options(int fd, char *options) |
| 217 | { |
| 218 | char *tok; |
| 219 | if (!options || !*options) return; |
| 220 | |
| 221 | options = strdup(options); |
| 222 | |
| 223 | if (!options) out_of_memory("set_socket_options"); |
| 224 | |
| 225 | for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) { |
| 226 | int ret=0,i; |
| 227 | int value = 1; |
| 228 | char *p; |
| 229 | int got_value = 0; |
| 230 | |
| 231 | if ((p = strchr(tok,'='))) { |
| 232 | *p = 0; |
| 233 | value = atoi(p+1); |
| 234 | got_value = 1; |
| 235 | } |
| 236 | |
| 237 | for (i=0;socket_options[i].name;i++) |
| 238 | if (strcmp(socket_options[i].name,tok)==0) |
| 239 | break; |
| 240 | |
| 241 | if (!socket_options[i].name) { |
| 242 | rprintf(FERROR,"Unknown socket option %s\n",tok); |
| 243 | continue; |
| 244 | } |
| 245 | |
| 246 | switch (socket_options[i].opttype) { |
| 247 | case OPT_BOOL: |
| 248 | case OPT_INT: |
| 249 | ret = setsockopt(fd,socket_options[i].level, |
| 250 | socket_options[i].option,(char *)&value,sizeof(int)); |
| 251 | break; |
| 252 | |
| 253 | case OPT_ON: |
| 254 | if (got_value) |
| 255 | rprintf(FERROR,"syntax error - %s does not take a value\n",tok); |
| 256 | |
| 257 | { |
| 258 | int on = socket_options[i].value; |
| 259 | ret = setsockopt(fd,socket_options[i].level, |
| 260 | socket_options[i].option,(char *)&on,sizeof(int)); |
| 261 | } |
| 262 | break; |
| 263 | } |
| 264 | |
| 265 | if (ret != 0) |
| 266 | rprintf(FERROR,"Failed to set socket option %s\n",tok); |
| 267 | } |
| 268 | |
| 269 | free(options); |
| 270 | } |
| 271 | |
| 272 | /**************************************************************************** |
| 273 | become a daemon, discarding the controlling terminal |
| 274 | ****************************************************************************/ |
| 275 | void become_daemon(void) |
| 276 | { |
| 277 | if (fork()) |
| 278 | _exit(0); |
| 279 | |
| 280 | /* detach from the terminal */ |
| 281 | #ifdef HAVE_SETSID |
| 282 | setsid(); |
| 283 | #else |
| 284 | #ifdef TIOCNOTTY |
| 285 | { |
| 286 | int i = open("/dev/tty", O_RDWR); |
| 287 | if (i >= 0) |
| 288 | { |
| 289 | ioctl(i, (int) TIOCNOTTY, (char *)0); |
| 290 | close(i); |
| 291 | } |
| 292 | } |
| 293 | #endif /* TIOCNOTTY */ |
| 294 | #endif |
| 295 | close(0); |
| 296 | close(1); |
| 297 | close(2); |
| 298 | } |
| 299 | |
| 300 | /******************************************************************* |
| 301 | return the IP addr of the client as a string |
| 302 | ******************************************************************/ |
| 303 | char *client_addr(int fd) |
| 304 | { |
| 305 | struct sockaddr sa; |
| 306 | struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); |
| 307 | int length = sizeof(sa); |
| 308 | static char addr_buf[100]; |
| 309 | |
| 310 | if (getpeername(fd, &sa, &length)) { |
| 311 | exit_cleanup(1); |
| 312 | } |
| 313 | |
| 314 | strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf)-1); |
| 315 | |
| 316 | return addr_buf; |
| 317 | } |
| 318 | |
| 319 | |
| 320 | /******************************************************************* |
| 321 | return the DNS name of the client |
| 322 | ******************************************************************/ |
| 323 | char *client_name(int fd) |
| 324 | { |
| 325 | struct sockaddr sa; |
| 326 | struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); |
| 327 | int length = sizeof(sa); |
| 328 | static char name_buf[100]; |
| 329 | struct hostent *hp; |
| 330 | char **p; |
| 331 | char *def = "UNKNOWN"; |
| 332 | |
| 333 | strcpy(name_buf,def); |
| 334 | |
| 335 | if (getpeername(fd, &sa, &length)) { |
| 336 | exit_cleanup(1); |
| 337 | } |
| 338 | |
| 339 | /* Look up the remote host name. */ |
| 340 | if ((hp = gethostbyaddr((char *) &sockin->sin_addr, |
| 341 | sizeof(sockin->sin_addr), |
| 342 | AF_INET))) { |
| 343 | strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf) - 1); |
| 344 | } |
| 345 | |
| 346 | |
| 347 | /* do a forward lookup as well to prevent spoofing */ |
| 348 | hp = gethostbyname(name_buf); |
| 349 | if (!hp) { |
| 350 | strcpy(name_buf,def); |
| 351 | rprintf(FERROR,"reverse name lookup failed\n"); |
| 352 | } else { |
| 353 | for (p=hp->h_addr_list;*p;p++) { |
| 354 | if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) { |
| 355 | break; |
| 356 | } |
| 357 | } |
| 358 | if (!*p) { |
| 359 | strcpy(name_buf,def); |
| 360 | rprintf(FERROR,"reverse name lookup mismatch - spoofed address?\n"); |
| 361 | } |
| 362 | } |
| 363 | |
| 364 | return name_buf; |
| 365 | } |