565 lines
14 KiB
C
565 lines
14 KiB
C
/* -*- c-file-style: "linux" -*-
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Copyright (C) 1998-2001 by Andrew Tridgell
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/*
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socket functions used in rsync
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*/
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#include "rsync.h"
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/* Establish a proxy connection on an open socket to a web roxy by
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* using the CONNECT method. */
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static int establish_proxy_connection(int fd, char *host, int port)
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{
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char buffer[1024];
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char *cp;
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snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);
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if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) {
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rprintf(FERROR, "failed to write to proxy: %s\n",
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strerror(errno));
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return -1;
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}
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for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) {
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if (read(fd, cp, 1) != 1) {
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rprintf(FERROR, "failed to read from proxy: %s\n",
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strerror(errno));
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return -1;
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}
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if (*cp == '\n')
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break;
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}
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if (*cp != '\n')
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cp++;
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*cp-- = '\0';
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if (*cp == '\r')
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*cp = '\0';
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if (strncmp(buffer, "HTTP/", 5) != 0) {
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rprintf(FERROR, "bad response from proxy - %s\n",
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buffer);
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return -1;
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}
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for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++)
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;
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while (*cp == ' ')
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cp++;
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if (*cp != '2') {
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rprintf(FERROR, "bad response from proxy - %s\n",
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buffer);
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return -1;
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}
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/* throw away the rest of the HTTP header */
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while (1) {
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for (cp = buffer; cp < &buffer[sizeof(buffer) - 1];
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cp++) {
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if (read(fd, cp, 1) != 1) {
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rprintf(FERROR, "failed to read from proxy: %s\n",
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strerror(errno));
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return -1;
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}
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if (*cp == '\n')
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break;
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}
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if ((cp > buffer) && (*cp == '\n'))
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cp--;
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if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))
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break;
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}
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return 0;
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}
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/* open a socket to a tcp remote host with the specified port
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based on code from Warren
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proxy support by Stephen Rothwell */
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int open_socket_out(char *host, int port, struct in_addr *address)
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{
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int type = SOCK_STREAM;
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struct sockaddr_in sock_out;
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struct sockaddr_in sock;
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int res;
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struct hostent *hp;
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char *h;
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unsigned p;
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int proxied = 0;
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char buffer[1024];
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char *cp;
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/* if we have a RSYNC_PROXY env variable then redirect our
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* connetcion via a web proxy at the given address. The format
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* is hostname:port */
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h = getenv("RSYNC_PROXY");
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proxied = (h != NULL) && (*h != '\0');
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if (proxied) {
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strlcpy(buffer, h, sizeof(buffer));
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cp = strchr(buffer, ':');
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if (cp == NULL) {
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rprintf(FERROR,
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"invalid proxy specification: should be HOST:PORT\n");
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return -1;
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}
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*cp++ = '\0';
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p = atoi(cp);
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h = buffer;
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} else {
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h = host;
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p = port;
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}
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res = socket(PF_INET, type, 0);
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if (res == -1) {
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return -1;
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}
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hp = gethostbyname(h);
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if (!hp) {
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rprintf(FERROR,"unknown host: %s\n", h);
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close(res);
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return -1;
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}
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memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length);
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sock_out.sin_port = htons(p);
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sock_out.sin_family = PF_INET;
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if (address) {
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sock.sin_addr = *address;
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sock.sin_port = 0;
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sock.sin_family = hp->h_addrtype;
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bind(res, (struct sockaddr * ) &sock,sizeof(sock));
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}
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if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) {
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rprintf(FERROR,"failed to connect to %s - %s\n", h, strerror(errno));
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close(res);
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return -1;
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}
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if (proxied && establish_proxy_connection(res, host, port) != 0) {
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close(res);
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return -1;
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}
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return res;
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}
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/****************************************************************************
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open a socket of the specified type, port and address for incoming data
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****************************************************************************/
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static int open_socket_in(int type, int port, struct in_addr *address)
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{
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struct hostent *hp;
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struct sockaddr_in sock;
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char host_name[MAXHOSTNAMELEN];
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int res;
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int one=1;
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/* get my host name */
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if (gethostname(host_name, sizeof(host_name)) == -1) {
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rprintf(FERROR,"gethostname failed\n");
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return -1;
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}
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/* get host info */
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if ((hp = gethostbyname(host_name)) == 0) {
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rprintf(FERROR,"gethostbyname: Unknown host %s\n",host_name);
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return -1;
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}
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memset((char *)&sock,0,sizeof(sock));
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memcpy((char *)&sock.sin_addr,(char *)hp->h_addr, hp->h_length);
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sock.sin_port = htons(port);
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sock.sin_family = hp->h_addrtype;
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if (address) {
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sock.sin_addr = *address;
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} else {
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sock.sin_addr.s_addr = INADDR_ANY;
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}
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res = socket(hp->h_addrtype, type, 0);
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if (res == -1) {
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rprintf(FERROR,"socket failed: %s\n",
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strerror(errno));
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return -1;
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}
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setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one));
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/* now we've got a socket - we need to bind it */
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if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) {
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rprintf(FERROR,"bind failed on port %d: %s\n", port,
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strerror(errno));
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if (errno == EACCES && port < 1024) {
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rprintf(FERROR, "Note: you must be root to bind "
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"to low-numbered ports");
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}
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close(res);
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return -1;
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}
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return res;
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}
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/*
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* Determine if a file descriptor is in fact a socket
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*/
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int is_a_socket(int fd)
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{
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int v;
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socklen_t l;
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l = sizeof(int);
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/* Parameters to getsockopt, setsockopt etc are very
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* unstandardized across platforms, so don't be surprised if
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* there are compiler warnings on e.g. SCO OpenSwerver or AIX.
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* It seems they all eventually get the right idea.
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*
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* Debian says: ``The fifth argument of getsockopt and
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* setsockopt is in reality an int [*] (and this is what BSD
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* 4.* and libc4 and libc5 have). Some POSIX confusion
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* resulted in the present socklen_t. The draft standard has
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* not been adopted yet, but glibc2 already follows it and
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* also has socklen_t [*]. See also accept(2).''
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*
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* We now return to your regularly scheduled programming. */
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return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
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}
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void start_accept_loop(int port, int (*fn)(int ))
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{
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int s;
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extern struct in_addr socket_address;
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/* open an incoming socket */
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s = open_socket_in(SOCK_STREAM, port, &socket_address);
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if (s == -1)
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exit_cleanup(RERR_SOCKETIO);
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/* ready to listen */
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if (listen(s, 5) == -1) {
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close(s);
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exit_cleanup(RERR_SOCKETIO);
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}
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/* now accept incoming connections - forking a new process
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for each incoming connection */
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while (1) {
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fd_set fds;
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int fd;
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struct sockaddr addr;
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int in_addrlen = sizeof(addr);
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/* close log file before the potentially very long select so
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file can be trimmed by another process instead of growing
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forever */
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log_close();
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FD_ZERO(&fds);
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FD_SET(s, &fds);
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if (select(s+1, &fds, NULL, NULL, NULL) != 1) {
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continue;
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}
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if(!FD_ISSET(s, &fds)) continue;
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/* See note above prototypes. */
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fd = accept(s,&addr,&in_addrlen);
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if (fd == -1) continue;
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signal(SIGCHLD, SIG_IGN);
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/* we shouldn't have any children left hanging around
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but I have had reports that on Digital Unix zombies
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are produced, so this ensures that they are reaped */
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#ifdef WNOHANG
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while (waitpid(-1, NULL, WNOHANG) > 0);
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#endif
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if (fork()==0) {
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close(s);
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/* open log file in child before possibly giving
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up privileges */
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log_open();
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_exit(fn(fd));
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}
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close(fd);
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}
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}
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enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON};
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struct
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{
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char *name;
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int level;
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int option;
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int value;
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int opttype;
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} socket_options[] = {
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{"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL},
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{"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL},
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{"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL},
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#ifdef TCP_NODELAY
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{"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL},
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#endif
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#ifdef IPTOS_LOWDELAY
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{"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON},
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#endif
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#ifdef IPTOS_THROUGHPUT
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{"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON},
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#endif
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#ifdef SO_SNDBUF
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{"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT},
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#endif
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#ifdef SO_RCVBUF
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{"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT},
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#endif
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#ifdef SO_SNDLOWAT
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{"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT},
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#endif
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#ifdef SO_RCVLOWAT
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{"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT},
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#endif
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#ifdef SO_SNDTIMEO
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{"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT},
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#endif
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#ifdef SO_RCVTIMEO
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{"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT},
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#endif
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{NULL,0,0,0,0}};
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/****************************************************************************
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set user socket options
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****************************************************************************/
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void set_socket_options(int fd, char *options)
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{
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char *tok;
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if (!options || !*options) return;
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options = strdup(options);
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if (!options) out_of_memory("set_socket_options");
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for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) {
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int ret=0,i;
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int value = 1;
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char *p;
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int got_value = 0;
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if ((p = strchr(tok,'='))) {
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*p = 0;
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value = atoi(p+1);
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got_value = 1;
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}
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for (i=0;socket_options[i].name;i++)
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if (strcmp(socket_options[i].name,tok)==0)
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break;
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if (!socket_options[i].name) {
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rprintf(FERROR,"Unknown socket option %s\n",tok);
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continue;
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}
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switch (socket_options[i].opttype) {
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case OPT_BOOL:
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case OPT_INT:
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ret = setsockopt(fd,socket_options[i].level,
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socket_options[i].option,(char *)&value,sizeof(int));
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break;
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case OPT_ON:
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if (got_value)
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rprintf(FERROR,"syntax error - %s does not take a value\n",tok);
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{
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int on = socket_options[i].value;
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ret = setsockopt(fd,socket_options[i].level,
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socket_options[i].option,(char *)&on,sizeof(int));
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}
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break;
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}
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if (ret != 0)
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rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
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strerror(errno));
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}
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free(options);
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}
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/****************************************************************************
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become a daemon, discarding the controlling terminal
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****************************************************************************/
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void become_daemon(void)
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{
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int i;
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if (fork()) {
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_exit(0);
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}
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/* detach from the terminal */
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#ifdef HAVE_SETSID
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setsid();
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#else
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#ifdef TIOCNOTTY
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i = open("/dev/tty", O_RDWR);
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if (i >= 0) {
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ioctl(i, (int) TIOCNOTTY, (char *)0);
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close(i);
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}
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#endif /* TIOCNOTTY */
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#endif
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/* make sure that stdin, stdout an stderr don't stuff things
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up (library functions, for example) */
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for (i=0;i<3;i++) {
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close(i);
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open("/dev/null", O_RDWR);
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}
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}
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/*******************************************************************
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return the IP addr of the client as a string
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******************************************************************/
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char *client_addr(int fd)
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{
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struct sockaddr sa;
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struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
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int length = sizeof(sa);
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static char addr_buf[100];
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static int initialised;
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if (initialised) return addr_buf;
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initialised = 1;
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if (getpeername(fd, &sa, &length)) {
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exit_cleanup(RERR_SOCKETIO);
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}
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strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf));
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return addr_buf;
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}
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/*******************************************************************
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return the DNS name of the client
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******************************************************************/
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char *client_name(int fd)
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{
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struct sockaddr sa;
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struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
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int length = sizeof(sa);
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static char name_buf[100];
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struct hostent *hp;
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char **p;
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char *def = "UNKNOWN";
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static int initialised;
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if (initialised) return name_buf;
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initialised = 1;
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strcpy(name_buf,def);
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if (getpeername(fd, &sa, &length)) {
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exit_cleanup(RERR_SOCKETIO);
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}
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/* Look up the remote host name. */
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if ((hp = gethostbyaddr((char *) &sockin->sin_addr,
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sizeof(sockin->sin_addr),
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AF_INET))) {
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strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf));
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}
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/* do a forward lookup as well to prevent spoofing */
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hp = gethostbyname(name_buf);
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if (!hp) {
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strcpy(name_buf,def);
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rprintf(FERROR,"reverse name lookup failed\n");
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} else {
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for (p=hp->h_addr_list;*p;p++) {
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if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) {
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break;
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}
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}
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if (!*p) {
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strcpy(name_buf,def);
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rprintf(FERROR,"reverse name lookup mismatch - spoofed address?\n");
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}
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}
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return name_buf;
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}
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/*******************************************************************
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convert a string to an IP address. The string can be a name or
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dotted decimal number
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******************************************************************/
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struct in_addr *ip_address(const char *str)
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{
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static struct in_addr ret;
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struct hostent *hp;
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/* try as an IP address */
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if (inet_aton(str, &ret) != 0) {
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return &ret;
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}
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/* otherwise assume it's a network name of some sort and use
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gethostbyname */
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if ((hp = gethostbyname(str)) == 0) {
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rprintf(FERROR, "gethostbyname: Unknown host. %s\n",str);
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return NULL;
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}
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if (hp->h_addr == NULL) {
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rprintf(FERROR, "gethostbyname: host address is invalid for host %s\n",str);
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return NULL;
|
|
}
|
|
|
|
if (hp->h_length > sizeof(ret)) {
|
|
rprintf(FERROR, "gethostbyname: host address is too large\n");
|
|
return NULL;
|
|
}
|
|
|
|
memcpy(&ret.s_addr, hp->h_addr, hp->h_length);
|
|
|
|
return(&ret);
|
|
}
|