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=a5ba32e4cd5cc32ca1bf83725702e98b013fd58c;hb=c5da48368569383d064a2325ab3b99d10287a085;hpb=77f54693ef258b1fe65ee105fc026dfb2c6257dc diff --git a/src/ngircd/resolve.c b/src/ngircd/resolve.c index a5ba32e4..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 1.17 2005/07/31 20:13:08 alex Exp $"; +/** + * @file + * Asynchronous resolver + */ -#include "imp.h" #include #include #include #include #include +#include +#include #include #include -#include #include #ifdef IDENTAUTH @@ -34,327 +36,425 @@ static char UNUSED id[] = "$Id: resolve.c,v 1.17 2005/07/31 20:13:08 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" -#include "io.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 -static void Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, int Sock, int w_fd )); -#else -static void Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, int w_fd )); +#ifdef WANT_IPV6 +extern bool Conf_ConnectIPv4; +extern bool Conf_ConnectIPv6; #endif -static void Do_ResolveName PARAMS(( char *Host, int w_fd )); -#ifdef h_errno -static char *Get_Error PARAMS(( int H_Error )); -#endif +/** + * Resolve IP (asynchronous!). + */ +GLOBAL bool +Resolve_Addr(PROC_STAT * s, const ng_ipaddr_t *Addr, int identsock, + void (*cbfunc) (int, short)) +{ + int pipefd[2]; + pid_t pid; -static RES_STAT *New_Res_Stat PARAMS(( void )); + assert(s != NULL); + 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_Subprocess("Resolver"); + Conn_CloseAllSockets(identsock); + Do_ResolveAddr(Addr, identsock, pipefd[1]); + Log_Exit_Subprocess("Resolver"); + exit(0); + } + return false; +} /* Resolve_Addr */ -static void -cb_resolver(int fd, short unused) { - (void) unused; /* shut up compiler warning */ - Read_Resolver_Result(fd); + +/** + * Resolve hostname (asynchronous!). + */ +GLOBAL bool +Resolve_Name( PROC_STAT *s, const char *Host, void (*cbfunc)(int, short)) +{ + int pipefd[2]; + pid_t pid; + + assert(s != NULL); + + 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 ); +#endif + return true; + } else if( pid == 0 ) { + /* Sub process */ + 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 -GLOBAL RES_STAT * -Resolve_Addr( struct sockaddr_in *Addr, int Sock ) + 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 -GLOBAL RES_STAT * -Resolve_Addr( struct sockaddr_in *Addr ) + (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) { - /* Resolve IP (asynchronous!). On errors, e.g. if the child process - * can't be forked, this functions returns NULL. */ + char tmp_ip_str[NG_INET_ADDRSTRLEN]; + const char *errmsg; +#ifdef HAVE_GETNAMEINFO + static const char funcname[]="getnameinfo"; + int res; - RES_STAT *s; - int pid; + *resbuf = 0; - s = New_Res_Stat( ); - if( ! s ) return NULL; + res = getnameinfo((struct sockaddr *) IpAddr, ng_ipaddr_salen(IpAddr), + resbuf, (socklen_t)reslen, NULL, 0, NI_NAMEREQD); + if (res == 0) + return true; - /* For sub-process */ - pid = fork( ); - if( pid > 0 ) - { - close( s->pipe[1] ); - /* Main process */ - Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid ); - if (!io_setnonblock( s->pipe[0] )) { - Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] ); - goto out; - } - if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) { - Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s", - s->pipe[0], strerror(errno) ); - goto out; - } - s->pid = pid; - return s; - } - else if( pid == 0 ) - { - close( s->pipe[0] ); - /* Sub process */ - Log_Init_Resolver( ); -#ifdef IDENTAUTH - Do_ResolveAddr( Addr, Sock, s->pipe[1] ); + if (res == EAI_SYSTEM) + errmsg = strerror(errno); + else + errmsg = gai_strerror(res); #else - Do_ResolveAddr( Addr, s->pipe[1] ); -#endif - Log_Exit_Resolver( ); - exit( 0 ); + const struct sockaddr_in *Addr = (const struct sockaddr_in *) IpAddr; + struct hostent *h; + 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 */ } - - Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno )); +#endif /* HAVE_GETNAMEINFO */ -out: /* Error! */ - close( s->pipe[0] ); - free( s ); -return NULL; -} /* Resolve_Addr */ + 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; +} -GLOBAL RES_STAT * -Resolve_Name( char *Host ) +/** + * 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) { - /* Resolve hostname (asynchronous!). On errors, e.g. if the child - * process can't be forked, this functions returns NULL. */ + ng_ipaddr_t addr; - RES_STAT *s; - int pid; +#ifdef HAVE_WORKING_GETADDRINFO + int res; + struct addrinfo *a, *ai_results; + static struct addrinfo hints; - s = New_Res_Stat( ); - if( ! s ) return NULL; +#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; + } - /* Fork sub-process */ - pid = fork( ); - if( pid > 0 ) - { - close( s->pipe[1] ); - /* Main process */ - Log( LOG_DEBUG, "Resolver for \"%s\" created (PID %d).", Host, pid ); - if (!io_setnonblock( s->pipe[0] )) { - Log( LOG_DEBUG, "Could not set Non-Blocking mode for pipefd %d", s->pipe[0] ); - goto out; - } - if (!io_event_create( s->pipe[0], IO_WANTREAD, cb_resolver )) { - Log( LOG_DEBUG, "Could not add pipefd %dto event watchlist: %s", - s->pipe[0], strerror(errno) ); - goto out; - } - s->pid = pid; - return s; + for (a = ai_results; a != NULL; a = a->ai_next) { + assert((size_t)a->ai_addrlen <= sizeof(addr)); + + 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; } - else if( pid == 0 ) - { - close( s->pipe[0] ); - /* Sub process */ - Log_Init_Resolver( ); - Do_ResolveName( Host, s->pipe[1] ); - Log_Exit_Resolver( ); - exit( 0 ); + + freeaddrinfo(ai_results); + return a == NULL; +#else + struct hostent *h = gethostbyname(hostname); + + if (!h) { +#ifdef h_errno + Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\": %s", + hostname, Get_Error(h_errno)); +#else + Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\"", hostname); +#endif + return false; } + memset(&addr, 0, sizeof(addr)); - Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno )); + addr.sin4.sin_family = AF_INET; + memcpy(&addr.sin4.sin_addr, h->h_addr, sizeof(struct in_addr)); -out: /* Error! */ - close( s->pipe[0] ); - free( s ); - return NULL; -} /* Resolve_Name */ + 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--; + } + /* 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--; + } + + return false; +} -#ifdef IDENTAUTH static void -Do_ResolveAddr( struct sockaddr_in *Addr, int Sock, int w_fd ) -#else +Log_Forgery_NoIP(const char *ip, const char *host) +{ + Log_Subprocess(LOG_WARNING, + "Possible forgery: %s resolved to \"%s\", which has no IP address!", + ip, host); +} + static void -Do_ResolveAddr( struct sockaddr_in *Addr, int w_fd ) -#endif +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); +} + + +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[HOST_LEN]; - char ipstr[HOST_LEN]; - struct hostent *h; + char hostname[CLIENT_HOST_LEN]; + char tmp_ip_str[NG_INET_ADDRSTRLEN]; size_t len; - struct in_addr *addr; - char *ntoaptr; -#ifdef IDENTAUTH - char *res; -#endif + array resolved_addr; - /* Resolve IP address */ + array_init(&resolved_addr); + ng_ipaddr_tostr_r(Addr, tmp_ip_str); #ifdef DEBUG - Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr )); + Log_Subprocess(LOG_DEBUG, "Now resolving %s ...", tmp_ip_str); #endif - h = gethostbyaddr( (char *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET ); - if (!h) { -#ifdef h_errno - Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), 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 )); - } else { - strlcpy( hostname, h->h_name, sizeof( hostname )); - - h = gethostbyname( hostname ); - if ( h ) { - if (memcmp(h->h_addr, &Addr->sin_addr, sizeof (struct in_addr))) { - addr = (struct in_addr*) h->h_addr; - strlcpy(ipstr, inet_ntoa(*addr), sizeof ipstr); - ntoaptr = inet_ntoa( Addr->sin_addr ); - Log(LOG_WARNING,"Possible forgery: %s resolved to %s (which is at ip %s!)", - ntoaptr, hostname, ipstr); - strlcpy( hostname, ntoaptr, sizeof hostname); - } - } else { - ntoaptr = inet_ntoa( Addr->sin_addr ); - Log(LOG_WARNING, "Possible forgery: %s resolved to %s (which has no ip address)", - ntoaptr, hostname); - strlcpy( hostname, ntoaptr, sizeof hostname); + 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)); } - Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname ); - - /* Write resolver result into pipe to parent */ - len = strlen( hostname ); - hostname[len] = '\n'; len++; - if( (size_t)write( w_fd, hostname, len ) != (size_t)len ) - { - 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; } -#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, "Ok, IDENT lookup on socket %d done: \"%s\"", Sock, res ? res : "" ); - - /* Write IDENT result into pipe to parent */ - if (res) { - len = strlen(res); - res[len] = '\n'; - len++; - } else len = 1; - - if( (size_t)write( w_fd, res ? res : "\n", len ) != (size_t)len ) - { - Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent (IDENT): %s!", strerror( errno )); - close( w_fd ); - } - free( res ); -#endif + Do_IdentQuery(identsock, &resolved_addr); + + ArrayWrite(w_fd, &resolved_addr); + + array_free(&resolved_addr); } /* Do_ResolveAddr */ static void -Do_ResolveName( char *Host, int w_fd ) +Do_ResolveName( const char *Host, int w_fd ) { /* 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); - char ip[16]; - struct hostent *h; - struct in_addr *addr; - int len; + array_init(&IpAddrs); - Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host ); +#ifdef WANT_IPV6 + af = AF_UNSPEC; + assert(Conf_ConnectIPv6 || Conf_ConnectIPv4); - /* 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 )); + if (!Conf_ConnectIPv6) + af = AF_INET; + if (!Conf_ConnectIPv4) + af = AF_INET6; #else - Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host ); + af = AF_INET; #endif - ip[0] = '\0'; - } - if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip ); - - /* Write result into pipe to parent */ - len = strlen( ip ); - ip[len] = '\n'; len++; - if( (size_t)write( w_fd, ip, len ) != (size_t)len ) - { - Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno )); - close( w_fd ); + if (!ForwardLookup(Host, &IpAddrs, af)) { + close(w_fd); + return; } -} /* Do_ResolveName */ - - -#ifdef 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"; - default: - return "unknown error"; +#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)); } -} /* Get_Error */ - #endif + /* Write result into pipe to parent */ + ArrayWrite(w_fd, &IpAddrs); - -static RES_STAT * -New_Res_Stat( void ) -{ - RES_STAT *s; - - /* Allocate memory */ - s = (RES_STAT *)malloc( sizeof( RES_STAT )); - if( ! s ) - { - Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Addr]" ); - return NULL; - } - - /* 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; - } - - s->stage = 0; - array_init(&s->buffer); - s->pid = -1; - - return s; -} /* New_Res_Stat */ + array_free(&IpAddrs); +} /* Do_ResolveName */ /* -eof- */