Index: squid/src/cf.data.pre
diff -c squid/src/cf.data.pre:1.199.2.8 squid/src/cf.data.pre:1.199.2.9
*** squid/src/cf.data.pre:1.199.2.8	Fri Apr  5 01:58:22 2002
--- squid/src/cf.data.pre	Sun Jun 23 14:10:16 2002
***************
*** 969,974 ****
--- 969,986 ----
  	connections, then turn off this option.
  DOC_END
  
+ NAME: ftp_sanitycheck
+ TYPE: onoff
+ DEFAULT: on
+ LOC: Config.Ftp.sanitycheck
+ DOC_START
+ 	For security and data integrity reasons Squid by default performs
+ 	sanity checks of the addresses of FTP data connections ensure the
+ 	data connection is to the requested server. If you need to allow
+ 	FTP connections to servers using another IP address for the data
+ 	connection then turn this off.
+ DOC_END
+ 
  NAME: cache_dns_program
  TYPE: string
  IFDEF: USE_DNSSERVERS
Index: squid/src/ftp.c
diff -c squid/src/ftp.c:1.298.2.6 squid/src/ftp.c:1.298.2.7
*** squid/src/ftp.c:1.298.2.6	Sat Feb 16 17:41:18 2002
--- squid/src/ftp.c	Sun Jun 23 14:10:16 2002
***************
*** 1020,1026 ****
  	    strCat(ftpState->base_href, rfc1738_escape_part(ftpState->password));
  	}
  	strCat(ftpState->base_href, "@");
! 	}
      strCat(ftpState->base_href, request->host);
      if (request->port != urlDefaultPort(PROTO_FTP)) {
  	strCat(ftpState->base_href, ":");
--- 1020,1026 ----
  	    strCat(ftpState->base_href, rfc1738_escape_part(ftpState->password));
  	}
  	strCat(ftpState->base_href, "@");
!     }
      strCat(ftpState->base_href, request->host);
      if (request->port != urlDefaultPort(PROTO_FTP)) {
  	strCat(ftpState->base_href, ":");
***************
*** 1721,1727 ****
      u_short port;
      int fd = ftpState->data.fd;
      char *buf = ftpState->ctrl.last_reply;
!     LOCAL_ARRAY(char, junk, 1024);
      debug(9, 3) ("This is ftpReadPasv\n");
      if (code != 227) {
  	debug(9, 3) ("PASV not supported by remote end\n");
--- 1721,1727 ----
      u_short port;
      int fd = ftpState->data.fd;
      char *buf = ftpState->ctrl.last_reply;
!     LOCAL_ARRAY(char, ipaddr, 1024);
      debug(9, 3) ("This is ftpReadPasv\n");
      if (code != 227) {
  	debug(9, 3) ("PASV not supported by remote end\n");
***************
*** 1737,1752 ****
      /*  ANSI sez [^0-9] is undefined, it breaks on Watcom cc */
      debug(9, 5) ("scanning: %s\n", buf);
      n = sscanf(buf, "%[^0123456789]%d,%d,%d,%d,%d,%d",
! 	junk, &h1, &h2, &h3, &h4, &p1, &p2);
      if (n != 7 || p1 < 0 || p2 < 0 || p1 > 255 || p2 > 255) {
  	debug(9, 3) ("Bad 227 reply\n");
  	debug(9, 3) ("n=%d, p1=%d, p2=%d\n", n, p1, p2);
  	ftpSendPort(ftpState);
  	return;
      }
!     snprintf(junk, 1024, "%d.%d.%d.%d", h1, h2, h3, h4);
!     if (!safe_inet_addr(junk, NULL)) {
! 	debug(9, 1) ("unsafe address (%s)\n", junk);
  	ftpSendPort(ftpState);
  	return;
      }
--- 1737,1752 ----
      /*  ANSI sez [^0-9] is undefined, it breaks on Watcom cc */
      debug(9, 5) ("scanning: %s\n", buf);
      n = sscanf(buf, "%[^0123456789]%d,%d,%d,%d,%d,%d",
! 	ipaddr, &h1, &h2, &h3, &h4, &p1, &p2);
      if (n != 7 || p1 < 0 || p2 < 0 || p1 > 255 || p2 > 255) {
  	debug(9, 3) ("Bad 227 reply\n");
  	debug(9, 3) ("n=%d, p1=%d, p2=%d\n", n, p1, p2);
  	ftpSendPort(ftpState);
  	return;
      }
!     snprintf(ipaddr, 1024, "%d.%d.%d.%d", h1, h2, h3, h4);
!     if (!safe_inet_addr(ipaddr, NULL)) {
! 	debug(9, 1) ("unsafe PASV address (%s) from %s\n", ipaddr, fd_table[ftpState->ctrl.fd].ipaddr);
  	ftpSendPort(ftpState);
  	return;
      }
***************
*** 1756,1768 ****
  	ftpSendPort(ftpState);
  	return;
      }
!     debug(9, 5) ("ftpReadPasv: connecting to %s, port %d\n", junk, port);
      ftpState->data.port = port;
!     ftpState->data.host = xstrdup(junk);
      safe_free(ftpState->ctrl.last_command);
      safe_free(ftpState->ctrl.last_reply);
      ftpState->ctrl.last_command = xstrdup("Connect to server data port");
!     commConnectStart(fd, junk, port, ftpPasvCallback, ftpState);
  }
  
  static void
--- 1756,1780 ----
  	ftpSendPort(ftpState);
  	return;
      }
!     if (Config.Ftp.sanitycheck) {
! 	if (strcmp(fd_table[ftpState->ctrl.fd].ipaddr, ipaddr) != 0) {
! 	    debug(9, 1) ("unsafe PASV address (%s) from %s\n", ipaddr, fd_table[ftpState->ctrl.fd].ipaddr);
! 	    ftpSendPort(ftpState);
! 	    return;
! 	}
! 	if (port < 1024) {
! 	    debug(9, 1) ("unsafe PASV port (%d) from %s\n", port, fd_table[ftpState->ctrl.fd].ipaddr);
! 	    ftpSendPort(ftpState);
! 	    return;
! 	}
!     }
!     debug(9, 5) ("ftpReadPasv: connecting to %s, port %d\n", ipaddr, port);
      ftpState->data.port = port;
!     ftpState->data.host = xstrdup(ipaddr);
      safe_free(ftpState->ctrl.last_command);
      safe_free(ftpState->ctrl.last_reply);
      ftpState->ctrl.last_command = xstrdup("Connect to server data port");
!     commConnectStart(fd, ipaddr, port, ftpPasvCallback, ftpState);
  }
  
  static void
***************
*** 1889,1894 ****
--- 1901,1919 ----
  	return;
      }
      fd = comm_accept(fd, &my_peer, &me);
+     if (Config.Ftp.sanitycheck) {
+ 	char *ipaddr = inet_ntoa(my_peer.sin_addr);
+ 	if (strcmp(fd_table[ftpState->ctrl.fd].ipaddr, ipaddr) != 0) {
+ 	    debug(9, 1) ("FTP data connection from unexpected server (%s:%d), expecting %s\n", ipaddr, (int) ntohs(my_peer.sin_port), fd_table[ftpState->ctrl.fd].ipaddr);
+ 	    comm_close(fd);
+ 	    commSetSelect(ftpState->data.fd,
+ 		COMM_SELECT_READ,
+ 		ftpAcceptDataConnection,
+ 		ftpState,
+ 		0);
+ 	    return;
+ 	}
+     }
      if (fd < 0) {
  	debug(9, 1) ("ftpHandleDataAccept: comm_accept(%d): %s", fd, xstrerror());
  	/* XXX Need to set error message */
Index: squid/src/structs.h
diff -c squid/src/structs.h:1.361.2.15 squid/src/structs.h:1.361.2.16
*** squid/src/structs.h:1.361.2.15	Mon Oct  8 09:22:03 2001
--- squid/src/structs.h	Sun Jun 23 14:10:17 2002
***************
*** 459,464 ****
--- 459,465 ----
  	int list_wrap;
  	char *anon_user;
  	int passive;
+ 	int sanitycheck;
      } Ftp;
      refresh_t *Refresh;
      struct _cacheSwap {