X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?p=ngircd-alex.git;a=blobdiff_plain;f=src%2Fngircd%2Fresolve.c;h=32791901215c475c95982616e8d95b321efe7680;hp=69705db5a104163f6befd8aec81d52c2b034c4ba;hb=62503353525fd893156731521edc95b2bd6a1f6f;hpb=b79b315dd4b5fcefb781d1e1e012f71e578a5346 diff --git a/src/ngircd/resolve.c b/src/ngircd/resolve.c index 69705db5..32791901 100644 --- a/src/ngircd/resolve.c +++ b/src/ngircd/resolve.c @@ -1,30 +1,32 @@ /* * ngIRCd -- The Next Generation IRC Daemon - * Copyright (c)2001-2003 by Alexander Barton (alex@barton.de) + * Copyright (c)2001-2014 Alexander Barton (alex@barton.de) and Contributors. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * Please read the file COPYING, README and AUTHORS for more information. - * - * Asynchronous resolver */ +#define RESOLVER_TIMEOUT (Conf_PongTimeout*3)/4 #include "portab.h" -static char UNUSED id[] = "$Id: resolve.c,v 1.7 2003/12/27 13:01:12 alex Exp $"; +/** + * @file + * Asynchronous resolver + */ -#include "imp.h" #include #include #include #include #include +#include +#include #include #include -#include #include #ifdef IDENTAUTH @@ -34,277 +36,425 @@ static char UNUSED id[] = "$Id: resolve.c,v 1.7 2003/12/27 13:01:12 alex Exp $"; #endif #include "conn.h" -#include "defines.h" +#include "conf.h" #include "log.h" +#include "ng_ipaddr.h" -#include "exp.h" #include "resolve.h" +static void Do_ResolveAddr PARAMS(( const ng_ipaddr_t *Addr, int Sock, int w_fd )); +static void Do_ResolveName PARAMS(( const char *Host, int w_fd )); -#ifdef IDENTAUTH -LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT Sock, INT w_fd )); -#else -LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT w_fd )); -#endif - -LOCAL VOID Do_ResolveName PARAMS(( CHAR *Host, INT w_fd )); - -#ifdef h_errno -LOCAL CHAR *Get_Error PARAMS(( INT H_Error )); +#ifdef WANT_IPV6 +extern bool Conf_ConnectIPv4; +extern bool Conf_ConnectIPv6; #endif -GLOBAL VOID -Resolve_Init( VOID ) -{ - /* Initialize module */ - - FD_ZERO( &Resolver_FDs ); -} /* Resolve_Init */ - - -#ifdef IDENTAUTH -GLOBAL RES_STAT * -Resolve_Addr( struct sockaddr_in *Addr, int Sock ) -#else -GLOBAL RES_STAT * -Resolve_Addr( struct sockaddr_in *Addr ) -#endif +/** + * Resolve IP (asynchronous!). + */ +GLOBAL bool +Resolve_Addr(PROC_STAT * s, const ng_ipaddr_t *Addr, int identsock, + void (*cbfunc) (int, short)) { - /* Resolve IP (asynchronous!). On errors, e.g. if the child process - * can't be forked, this functions returns NULL. */ - - RES_STAT *s; - INT pid; - - /* Allocate memory */ - s = malloc( sizeof( RES_STAT )); - if( ! s ) - { - Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Addr]" ); - return NULL; - } + int pipefd[2]; + pid_t pid; - /* Initialize pipe for result */ - if( pipe( s->pipe ) != 0 ) - { - free( s ); - Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno )); - return NULL; - } + assert(s != NULL); - /* For sub-process */ - pid = fork( ); - if( pid > 0 ) - { - /* Main process */ - Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid ); - FD_SET( s->pipe[0], &Resolver_FDs ); - if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0]; - s->pid = pid; - return s; - } - else if( pid == 0 ) - { + pid = Proc_Fork(s, pipefd, cbfunc, RESOLVER_TIMEOUT); + if (pid > 0) { + LogDebug("Resolver for %s created (PID %d).", ng_ipaddr_tostr(Addr), pid); + return true; + } else if( pid == 0 ) { /* Sub process */ - Log_Init_Resolver( ); -#ifdef IDENTAUTH - Do_ResolveAddr( Addr, Sock, s->pipe[1] ); -#else - Do_ResolveAddr( Addr, s->pipe[1] ); -#endif - Log_Exit_Resolver( ); - exit( 0 ); - } - else - { - /* Error! */ - free( s ); - Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno )); - return NULL; + Log_Init_Subprocess("Resolver"); + Conn_CloseAllSockets(identsock); + Do_ResolveAddr(Addr, identsock, pipefd[1]); + Log_Exit_Subprocess("Resolver"); + exit(0); } + return false; } /* Resolve_Addr */ -GLOBAL RES_STAT * -Resolve_Name( CHAR *Host ) +/** + * Resolve hostname (asynchronous!). + */ +GLOBAL bool +Resolve_Name( PROC_STAT *s, const char *Host, void (*cbfunc)(int, short)) { - /* Resolve hostname (asynchronous!). On errors, e.g. if the child - * process can't be forked, this functions returns NULL. */ - - RES_STAT *s; - INT pid; - - /* Allocate memory */ - s = malloc( sizeof( RES_STAT )); - if( ! s ) - { - Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Name]" ); - return NULL; - } + int pipefd[2]; + pid_t pid; - /* Initialize the pipe for the result */ - if( pipe( s->pipe ) != 0 ) - { - free( s ); - Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno )); - return NULL; - } + assert(s != NULL); - /* Fork sub-process */ - pid = fork( ); - if( pid > 0 ) - { + pid = Proc_Fork(s, pipefd, cbfunc, RESOLVER_TIMEOUT); + if (pid > 0) { /* Main process */ +#ifdef DEBUG Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid ); - FD_SET( s->pipe[0], &Resolver_FDs ); - if( s->pipe[0] > Conn_MaxFD ) Conn_MaxFD = s->pipe[0]; - s->pid = pid; - return s; - } - else if( pid == 0 ) - { +#endif + return true; + } else if( pid == 0 ) { /* Sub process */ - Log_Init_Resolver( ); - Do_ResolveName( Host, s->pipe[1] ); - Log_Exit_Resolver( ); - exit( 0 ); - } - else - { - /* Error! */ - free( s ); - Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno )); - return NULL; + Log_Init_Subprocess("Resolver"); + Conn_CloseAllSockets(NONE); + Do_ResolveName(Host, pipefd[1]); + Log_Exit_Subprocess("Resolver"); + exit(0); } + return false; } /* Resolve_Name */ +#if !defined(HAVE_GETADDRINFO) || !defined(HAVE_GETNAMEINFO) +#if !defined(WANT_IPV6) && defined(h_errno) +static char * +Get_Error( int H_Error ) +{ + /* Get error message for H_Error */ + switch( H_Error ) { + case HOST_NOT_FOUND: + return "host not found"; + case NO_DATA: + return "name valid but no IP address defined"; + case NO_RECOVERY: + return "name server error"; + case TRY_AGAIN: + return "name server temporary not available"; + } + return "unknown error"; +} +#endif +#endif + + +/* Do "IDENT" (aka "AUTH") lookup and append result to resolved_addr array */ +static void +Do_IdentQuery(int identsock, array *resolved_addr) +{ #ifdef IDENTAUTH -LOCAL VOID -Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, INT w_fd ) + char *res; + + if (identsock < 0) + return; + +#ifdef DEBUG + Log_Subprocess(LOG_DEBUG, "Doing IDENT lookup on socket %d ...", + identsock); +#endif + res = ident_id( identsock, 10 ); +#ifdef DEBUG + Log_Subprocess(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", + identsock, res ? res : "(NULL)"); +#endif + if (!res) /* no result */ + return; + if (!array_cats(resolved_addr, res)) + Log_Subprocess(LOG_WARNING, + "Resolver: Cannot copy IDENT result: %s!", + strerror(errno)); + + free(res); #else -LOCAL VOID -Do_ResolveAddr( struct sockaddr_in *Addr, INT w_fd ) + (void) identsock; + (void) resolved_addr; #endif +} + + +/** + * perform reverse DNS lookup and put result string into resbuf. + * If no hostname could be obtained, this function stores the string representation of + * the IP address in resbuf and returns false. + * @param IpAddr ip address to resolve + * @param resbuf result buffer to store DNS name/string representation of ip address + * @param reslen size of result buffer (must be >= NGT_INET_ADDRSTRLEN) + * @return true if reverse lookup successful, false otherwise + */ +static bool +ReverseLookup(const ng_ipaddr_t *IpAddr, char *resbuf, size_t reslen) { - /* Resolver sub-process: resolve IP address and write result into - * pipe to parent. */ + char tmp_ip_str[NG_INET_ADDRSTRLEN]; + const char *errmsg; +#ifdef HAVE_GETNAMEINFO + static const char funcname[]="getnameinfo"; + int res; - CHAR hostname[HOST_LEN]; + *resbuf = 0; + + res = getnameinfo((struct sockaddr *) IpAddr, ng_ipaddr_salen(IpAddr), + resbuf, (socklen_t)reslen, NULL, 0, NI_NAMEREQD); + if (res == 0) + return true; + + if (res == EAI_SYSTEM) + errmsg = strerror(errno); + else + errmsg = gai_strerror(res); +#else + const struct sockaddr_in *Addr = (const struct sockaddr_in *) IpAddr; struct hostent *h; -#ifdef IDENTAUTH - CHAR *res; + static const char funcname[]="gethostbyaddr"; + + h = gethostbyaddr((char *)&Addr->sin_addr, sizeof(Addr->sin_addr), AF_INET); + if (h) { + if (strlcpy(resbuf, h->h_name, reslen) < reslen) + return true; + errmsg = "hostname too long"; + } else { +# ifdef h_errno + errmsg = Get_Error(h_errno); +# else + errmsg = "unknown error"; +# endif /* h_errno */ + } +#endif /* HAVE_GETNAMEINFO */ + + assert(errmsg); + assert(reslen >= NG_INET_ADDRSTRLEN); + ng_ipaddr_tostr_r(IpAddr, tmp_ip_str); + + Log_Subprocess(LOG_WARNING, "Can't resolve address \"%s\": %s [%s].", + tmp_ip_str, errmsg, funcname); + strlcpy(resbuf, tmp_ip_str, reslen); + return false; +} + + +/** + * perform DNS lookup of given host name and fill IpAddr with a list of + * ip addresses associated with that name. + * ip addresses found are stored in the "array *IpAddr" argument (type ng_ipaddr_t) + * @param hostname The domain name to look up. + * @param IpAddr pointer to empty and initialized array to store results + * @return true if lookup successful, false if domain name not found + */ +static bool +ForwardLookup(const char *hostname, array *IpAddr, int af) +{ + ng_ipaddr_t addr; + +#ifdef HAVE_WORKING_GETADDRINFO + int res; + struct addrinfo *a, *ai_results; + static struct addrinfo hints; + +#ifdef AI_ADDRCONFIG /* glibc has this, but not e.g. netbsd 4.0 */ + hints.ai_flags = AI_ADDRCONFIG; #endif + hints.ai_socktype = SOCK_STREAM; + hints.ai_protocol = IPPROTO_TCP; + hints.ai_family = af; + + memset(&addr, 0, sizeof(addr)); + + res = getaddrinfo(hostname, NULL, &hints, &ai_results); + switch (res) { + case 0: break; + case EAI_SYSTEM: + Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, strerror(errno)); + return false; + default: + Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, gai_strerror(res)); + return false; + } - Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr )); + for (a = ai_results; a != NULL; a = a->ai_next) { + assert((size_t)a->ai_addrlen <= sizeof(addr)); - /* Resolve IP address */ - h = gethostbyaddr( (CHAR *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET ); - if( h ) strlcpy( hostname, h->h_name, sizeof( hostname )); - else - { + if ((size_t)a->ai_addrlen > sizeof(addr)) + continue; + + memcpy(&addr, a->ai_addr, a->ai_addrlen); + + if (!array_catb(IpAddr, (char *)&addr, sizeof(addr))) + break; + } + + freeaddrinfo(ai_results); + return a == NULL; +#else + struct hostent *h = gethostbyname(hostname); + + if (!h) { #ifdef h_errno - Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno )); + Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", + hostname, Get_Error(h_errno)); #else - Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr )); -#endif - strlcpy( hostname, inet_ntoa( Addr->sin_addr ), sizeof( hostname )); + Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\"", hostname); +#endif + return false; } + memset(&addr, 0, sizeof(addr)); -#ifdef IDENTAUTH - /* Do "IDENT" (aka "AUTH") lookup and write result to parent */ - Log_Resolver( LOG_DEBUG, "Doing IDENT lookup on socket %d ...", Sock ); - res = ident_id( Sock, 10 ); - Log_Resolver( LOG_DEBUG, "IDENT lookup on socket %d done.", Sock ); -#endif + addr.sin4.sin_family = AF_INET; + memcpy(&addr.sin4.sin_addr, h->h_addr, sizeof(struct in_addr)); - /* Write result into pipe to parent */ - if( (size_t)write( w_fd, hostname, strlen( hostname ) + 1 ) != (size_t)( strlen( hostname ) + 1 )) - { - Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno )); - close( w_fd ); - return; + return array_copyb(IpAddr, (char *)&addr, sizeof(addr)); +#endif /* HAVE_GETADDRINFO */ +} + + +static bool +Addr_in_list(const array *resolved_addr, const ng_ipaddr_t *Addr) +{ + char tmp_ip_str[NG_INET_ADDRSTRLEN]; + const ng_ipaddr_t *tmpAddrs = array_start(resolved_addr); + size_t len = array_length(resolved_addr, sizeof(*tmpAddrs)); + + assert(len > 0); + assert(tmpAddrs); + + while (len > 0) { + if (ng_ipaddr_ipequal(Addr, tmpAddrs)) + return true; + tmpAddrs++; + len--; } -#ifdef IDENTAUTH - if( (size_t)write( w_fd, res ? res : "", strlen( res ? res : "" ) + 1 ) != (size_t)( strlen( res ? res : "" ) + 1 )) - { - Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent (IDENT): %s!", strerror( errno )); - close( w_fd ); - free( res ); - return; + /* failed; print list of addresses */ + ng_ipaddr_tostr_r(Addr, tmp_ip_str); + len = array_length(resolved_addr, sizeof(*tmpAddrs)); + tmpAddrs = array_start(resolved_addr); + + while (len > 0) { + Log_Subprocess(LOG_WARNING, "Address mismatch: %s != %s", + tmp_ip_str, ng_ipaddr_tostr(tmpAddrs)); + tmpAddrs++; + len--; } - free( res ); -#endif - Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname ); -} /* Do_ResolveAddr */ + return false; +} -LOCAL VOID -Do_ResolveName( CHAR *Host, INT w_fd ) +static void +Log_Forgery_NoIP(const char *ip, const char *host) { - /* Resolver sub-process: resolve name and write result into pipe - * to parent. */ + Log_Subprocess(LOG_WARNING, + "Possible forgery: %s resolved to \"%s\", which has no IP address!", + ip, host); +} - CHAR ip[16]; - struct hostent *h; - struct in_addr *addr; +static void +Log_Forgery_WrongIP(const char *ip, const char *host) +{ + Log_Subprocess(LOG_WARNING, + "Possible forgery: %s resolved to \"%s\", which points to a different address!", + ip, host); +} - Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host ); - /* Resolve hostname */ - h = gethostbyname( Host ); - if( h ) - { - addr = (struct in_addr *)h->h_addr; - strlcpy( ip, inet_ntoa( *addr ), sizeof( ip )); - } - else - { -#ifdef h_errno - Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, Get_Error( h_errno )); -#else - Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host ); +static void +ArrayWrite(int fd, const array *a) +{ + size_t len = array_bytes(a); + const char *data = array_start(a); + + assert(data); + + if( (size_t)write(fd, data, len) != len ) + Log_Subprocess( LOG_CRIT, "Resolver: Can't write to parent: %s!", + strerror(errno)); +} + + +static void +Do_ResolveAddr(const ng_ipaddr_t *Addr, int identsock, int w_fd) +{ + /* Resolver sub-process: resolve IP address and write result into + * pipe to parent. */ + char hostname[CLIENT_HOST_LEN]; + char tmp_ip_str[NG_INET_ADDRSTRLEN]; + size_t len; + array resolved_addr; + + array_init(&resolved_addr); + ng_ipaddr_tostr_r(Addr, tmp_ip_str); +#ifdef DEBUG + Log_Subprocess(LOG_DEBUG, "Now resolving %s ...", tmp_ip_str); #endif - strcpy( ip, "" ); + if (!ReverseLookup(Addr, hostname, sizeof(hostname))) + goto dns_done; + + if (ForwardLookup(hostname, &resolved_addr, ng_ipaddr_af(Addr))) { + if (!Addr_in_list(&resolved_addr, Addr)) { + Log_Forgery_WrongIP(tmp_ip_str, hostname); + strlcpy(hostname, tmp_ip_str, sizeof(hostname)); + } + } else { + Log_Forgery_NoIP(tmp_ip_str, hostname); + strlcpy(hostname, tmp_ip_str, sizeof(hostname)); } - - /* Write result into pipe to parent */ - if( (size_t)write( w_fd, ip, strlen( ip ) + 1 ) != (size_t)( strlen( ip ) + 1 )) - { - Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno )); - close( w_fd ); +#ifdef DEBUG + Log_Subprocess(LOG_DEBUG, "Ok, translated %s to \"%s\".", tmp_ip_str, hostname); +#endif + dns_done: + len = strlen(hostname); + hostname[len] = '\n'; + if (!array_copyb(&resolved_addr, hostname, ++len)) { + Log_Subprocess(LOG_CRIT, + "Resolver: Can't copy resolved name: %s!", + strerror(errno)); + array_free(&resolved_addr); return; } - if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip ); -} /* Do_ResolveName */ + Do_IdentQuery(identsock, &resolved_addr); + ArrayWrite(w_fd, &resolved_addr); -#ifdef h_errno + array_free(&resolved_addr); +} /* Do_ResolveAddr */ -LOCAL CHAR * -Get_Error( INT H_Error ) + +static void +Do_ResolveName( const char *Host, int w_fd ) { - /* Get error message for H_Error */ + /* Resolver sub-process: resolve name and write result into pipe + * to parent. */ + array IpAddrs; + int af; +#ifdef DEBUG + ng_ipaddr_t *addr; + size_t len; +#endif + Log_Subprocess(LOG_DEBUG, "Now resolving \"%s\" ...", Host); - switch( H_Error ) - { - case HOST_NOT_FOUND: - return "host not found"; - case NO_DATA: - return "name valid but no IP address defined"; - case NO_RECOVERY: - return "name server error"; - case TRY_AGAIN: - return "name server temporary not available"; - default: - return "unknown error"; - } -} /* Get_Error */ + array_init(&IpAddrs); +#ifdef WANT_IPV6 + af = AF_UNSPEC; + assert(Conf_ConnectIPv6 || Conf_ConnectIPv4); + + if (!Conf_ConnectIPv6) + af = AF_INET; + if (!Conf_ConnectIPv4) + af = AF_INET6; +#else + af = AF_INET; #endif + if (!ForwardLookup(Host, &IpAddrs, af)) { + close(w_fd); + return; + } +#ifdef DEBUG + len = array_length(&IpAddrs, sizeof(*addr)); + assert(len > 0); + addr = array_start(&IpAddrs); + assert(addr); + for (; len > 0; --len,addr++) { + Log_Subprocess(LOG_DEBUG, "translated \"%s\" to %s.", + Host, ng_ipaddr_tostr(addr)); + } +#endif + /* Write result into pipe to parent */ + ArrayWrite(w_fd, &IpAddrs); + + array_free(&IpAddrs); +} /* Do_ResolveName */ /* -eof- */