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=e46e4823b31792a83f198a540e6ef15e065888b0;hb=62503353525fd893156731521edc95b2bd6a1f6f;hpb=0701afedee21b33e22f663ca265a7ca0f4c43974 diff --git a/src/ngircd/resolve.c b/src/ngircd/resolve.c index e46e4823..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 1.23 2006/02/08 15:24:10 fw Exp $"; +/** + * @file + * Asynchronous resolver + */ -#include "imp.h" #include #include #include #include #include +#include +#include #include #include -#include #include #ifdef IDENTAUTH @@ -34,326 +36,425 @@ static char UNUSED id[] = "$Id: resolve.c,v 1.23 2006/02/08 15:24:10 fw 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(( struct sockaddr_in *Addr, int Sock, int w_fd )); +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 )); -static bool register_callback PARAMS((RES_STAT *s, void (*cbfunc)(int, short))); -#ifdef h_errno -static char *Get_Error PARAMS(( int H_Error )); +#ifdef WANT_IPV6 +extern bool Conf_ConnectIPv4; +extern bool Conf_ConnectIPv6; #endif -static int -Resolver_fork(int *pipefds) -{ - int pid; - if (pipe(pipefds) != 0) { - Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno )); - return -1; - } - - pid = fork(); - switch(pid) { - case -1: - Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno )); - close(pipefds[0]); - close(pipefds[1]); - return -1; - case 0: /* child */ - close(pipefds[0]); - Log_Init_Resolver( ); - return 0; - } - /* parent */ - close(pipefds[1]); - return pid; -} - +/** + * Resolve IP (asynchronous!). + */ GLOBAL bool -Resolve_Addr( RES_STAT *s, struct sockaddr_in *Addr, int identsock, void (*cbfunc)(int, short)) +Resolve_Addr(PROC_STAT * s, const ng_ipaddr_t *Addr, int identsock, + void (*cbfunc) (int, short)) { - /* Resolve IP (asynchronous!). */ - int pid, pipefd[2]; + int pipefd[2]; + pid_t pid; + assert(s != NULL); - pid = Resolver_fork(pipefd); + pid = Proc_Fork(s, pipefd, cbfunc, RESOLVER_TIMEOUT); if (pid > 0) { -#ifdef DEBUG - Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid ); -#endif - s->pid = pid; - s->resolver_fd = pipefd[0]; - return register_callback(s, cbfunc); + LogDebug("Resolver for %s created (PID %d).", ng_ipaddr_tostr(Addr), pid); + return true; } else if( pid == 0 ) { /* Sub process */ - Do_ResolveAddr( Addr, identsock, pipefd[1]); - Log_Exit_Resolver( ); + Log_Init_Subprocess("Resolver"); + Conn_CloseAllSockets(identsock); + Do_ResolveAddr(Addr, identsock, pipefd[1]); + Log_Exit_Subprocess("Resolver"); exit(0); } return false; } /* Resolve_Addr */ +/** + * Resolve hostname (asynchronous!). + */ GLOBAL bool -Resolve_Name( RES_STAT *s, const char *Host, void (*cbfunc)(int, short)) +Resolve_Name( PROC_STAT *s, const char *Host, void (*cbfunc)(int, short)) { - /* Resolve hostname (asynchronous!). */ - int pid, pipefd[2]; + int pipefd[2]; + pid_t pid; + assert(s != NULL); - pid = Resolver_fork(pipefd); + 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 - s->pid = pid; - s->resolver_fd = pipefd[0]; - return register_callback(s, cbfunc); + return true; } else if( pid == 0 ) { /* Sub process */ + Log_Init_Subprocess("Resolver"); + Conn_CloseAllSockets(NONE); Do_ResolveName(Host, pipefd[1]); - Log_Exit_Resolver( ); + Log_Exit_Subprocess("Resolver"); exit(0); } return false; } /* Resolve_Name */ -GLOBAL void -Resolve_Init(RES_STAT *s) +#if !defined(HAVE_GETADDRINFO) || !defined(HAVE_GETNAMEINFO) +#if !defined(WANT_IPV6) && defined(h_errno) +static char * +Get_Error( int H_Error ) { - assert(s != NULL); - s->resolver_fd = -1; - s->pid = 0; + /* 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_ResolveAddr( struct sockaddr_in *Addr, int identsock, int w_fd ) +Do_IdentQuery(int identsock, array *resolved_addr) { - /* Resolver sub-process: resolve IP address and write result into - * pipe to parent. */ - - char hostname[HOST_LEN]; - char ipstr[HOST_LEN]; - struct hostent *h; - size_t len; - struct in_addr *addr; - char *ntoaptr; - array resolved_addr; #ifdef IDENTAUTH char *res; -#endif - array_init(&resolved_addr); - /* Resolve IP address */ -#ifdef DEBUG - Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr )); -#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); - } - } - Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname ); - len = strlen( hostname ); - hostname[len] = '\n'; len++; - if (!array_copyb(&resolved_addr, hostname, len )) { - Log_Resolver( LOG_CRIT, "Resolver: Can't copy resolved name: %s!", strerror( errno )); - close( w_fd ); + if (identsock < 0) return; - } -#ifdef IDENTAUTH - assert(identsock >= 0); - if (identsock >= 0) { - /* Do "IDENT" (aka "AUTH") lookup and append result to resolved_addr array */ #ifdef DEBUG - Log_Resolver( LOG_DEBUG, "Doing IDENT lookup on socket %d ...", identsock ); + Log_Subprocess(LOG_DEBUG, "Doing IDENT lookup on socket %d ...", + identsock); #endif - res = ident_id( identsock, 10 ); + res = ident_id( identsock, 10 ); #ifdef DEBUG - Log_Resolver(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", - identsock, res ? res : "(NULL)" ); + Log_Subprocess(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"", + identsock, res ? res : "(NULL)"); #endif - if (res && !array_cats(&resolved_addr, res)) { - Log_Resolver(LOG_WARNING, "Resolver: Cannot copy IDENT result: %s!", strerror(errno)); - /* omit ident and return hostname only */ - } + if (!res) /* no result */ + return; + if (!array_cats(resolved_addr, res)) + Log_Subprocess(LOG_WARNING, + "Resolver: Cannot copy IDENT result: %s!", + strerror(errno)); - if (res) free(res); - } + free(res); #else - (void)identsock; + (void) identsock; + (void) resolved_addr; #endif - len = array_bytes(&resolved_addr); - if( (size_t)write( w_fd, array_start(&resolved_addr), len) != len ) - Log_Resolver( LOG_CRIT, "Resolver: Can't write result to parent: %s!", strerror( errno )); - - close(w_fd); - array_free(&resolved_addr); -} /* Do_ResolveAddr */ +} -static void -Do_ResolveName( const char *Host, int w_fd ) +/** + * 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 name and write result into pipe - * to parent. */ - - char ip[16]; + char tmp_ip_str[NG_INET_ADDRSTRLEN]; + const char *errmsg; +#ifdef HAVE_GETNAMEINFO + static const char funcname[]="getnameinfo"; + int res; + + *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; - struct in_addr *addr; - int len; - - Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host ); + static const char funcname[]="gethostbyaddr"; - /* Resolve hostname */ - h = gethostbyname( Host ); - if( h ) { - addr = (struct in_addr *)h->h_addr; - strlcpy( ip, inet_ntoa( *addr ), sizeof( ip )); + 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 - Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, Get_Error( h_errno )); -#else - Log_Resolver( LOG_WARNING, "Can't resolve \"%s\"!", Host ); -#endif - close(w_fd); - return; +# ifdef h_errno + errmsg = Get_Error(h_errno); +# else + errmsg = "unknown error"; +# endif /* h_errno */ } -#ifdef DEBUG - Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip ); +#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 - /* Write result into pipe to parent */ - len = strlen( ip ); - if( write( w_fd, ip, len ) != len) { - Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno )); - close( w_fd ); + 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; } -} /* Do_ResolveName */ + for (a = ai_results; a != NULL; a = a->ai_next) { + assert((size_t)a->ai_addrlen <= sizeof(addr)); -#ifdef h_errno + if ((size_t)a->ai_addrlen > sizeof(addr)) + continue; -static char * -Get_Error( int H_Error ) -{ - /* Get error message for H_Error */ + memcpy(&addr, a->ai_addr, a->ai_addrlen); - 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"; + if (!array_catb(IpAddr, (char *)&addr, sizeof(addr))) + break; } -} /* Get_Error */ + 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)); + + addr.sin4.sin_family = AF_INET; + memcpy(&addr.sin4.sin_addr, h->h_addr, sizeof(struct in_addr)); + + return array_copyb(IpAddr, (char *)&addr, sizeof(addr)); +#endif /* HAVE_GETADDRINFO */ +} static bool -register_callback( RES_STAT *s, void (*cbfunc)(int, short)) +Addr_in_list(const array *resolved_addr, const ng_ipaddr_t *Addr) { - assert(cbfunc); - assert(s != NULL); - assert(s->resolver_fd >= 0); + 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); - if (io_setnonblock(s->resolver_fd) && - io_event_create(s->resolver_fd, IO_WANTREAD, cbfunc)) + 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--; + } - Log( LOG_CRIT, "Resolver: Could not register callback function: %s!", strerror(errno)); - Resolve_Shutdown(s); return false; } -GLOBAL bool -Resolve_Shutdown( RES_STAT *s) +static void +Log_Forgery_NoIP(const char *ip, const char *host) { - bool ret = false; + Log_Subprocess(LOG_WARNING, + "Possible forgery: %s resolved to \"%s\", which has no IP address!", + ip, host); +} - assert(s != NULL); - assert(s->resolver_fd >= 0); +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); +} - if (s->resolver_fd >= 0) - ret = io_close(s->resolver_fd); - Resolve_Init(s); - return ret; +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)); } - -GLOBAL size_t -Resolve_Read( RES_STAT *s, void* readbuf, size_t buflen) + +static void +Do_ResolveAddr(const ng_ipaddr_t *Addr, int identsock, int w_fd) { - /* Read result of resolver sub-process from pipe */ - int err, bytes_read; - assert(buflen > 0); - - /* Read result from pipe */ - errno = 0; - bytes_read = read(s->resolver_fd, readbuf, buflen); - if (bytes_read < 0) { - if (errno != EAGAIN) { - err = errno; - Log( LOG_CRIT, "Resolver: Can't read result: %s!", strerror(err)); - Resolve_Shutdown(s); - errno = err; - return 0; + /* 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 + 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)); } - return 0; + } else { + Log_Forgery_NoIP(tmp_ip_str, hostname); + strlcpy(hostname, tmp_ip_str, sizeof(hostname)); + } +#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; } - Resolve_Shutdown(s); - if (bytes_read == 0) { /* EOF: lookup failed */ + Do_IdentQuery(identsock, &resolved_addr); + + ArrayWrite(w_fd, &resolved_addr); + + array_free(&resolved_addr); +} /* Do_ResolveAddr */ + + +static void +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 - Log( LOG_DEBUG, "Resolver: Can't read result: EOF"); + ng_ipaddr_t *addr; + size_t len; +#endif + Log_Subprocess(LOG_DEBUG, "Now resolving \"%s\" ...", Host); + + 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 - return 0; + 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); - return bytes_read; -} -/* -eof- */ + array_free(&IpAddrs); +} /* Do_ResolveName */ + +/* -eof- */