/*
* ngIRCd -- The Next Generation IRC Daemon
- * Copyright (c)2001,2002 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 1.4 2002/12/12 12:24:18 alex Exp $";
+/**
+ * @file
+ * Asynchronous resolver
+ */
-#include "imp.h"
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
-#include <arpa/inet.h>
#include <netdb.h>
+#ifdef IDENTAUTH
+#ifdef HAVE_IDENT_H
+#include <ident.h>
+#endif
+#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 ));
-LOCAL VOID Do_ResolveAddr PARAMS(( struct sockaddr_in *Addr, INT w_fd ));
-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 )
+/**
+ * Resolve IP (asynchronous!).
+ */
+GLOBAL bool
+Resolve_Addr(PROC_STAT * s, const ng_ipaddr_t *Addr, int identsock,
+ void (*cbfunc) (int, short))
{
- /* Modul initialisieren */
-
- FD_ZERO( &Resolver_FDs );
-} /* Resolve_Init */
+ int pipefd[2];
+ pid_t pid;
+
+ 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 */
-GLOBAL RES_STAT *
-Resolve_Addr( struct sockaddr_in *Addr )
+/**
+ * Resolve hostname (asynchronous!).
+ */
+GLOBAL bool
+Resolve_Name( PROC_STAT *s, const char *Host, void (*cbfunc)(int, short))
{
- /* IP (asyncron!) aufloesen. Bei Fehler, z.B. wenn der
- * Child-Prozess nicht erzeugt werden kann, wird NULL geliefert.
- * Der Host kann dann nicht aufgeloest werden. */
-
- RES_STAT *s;
- INT pid;
-
- /* Speicher anfordern */
- 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;
- /* Pipe fuer Antwort initialisieren */
- if( pipe( s->pipe ) != 0 )
- {
- free( s );
- Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
- return NULL;
- }
+ assert(s != NULL);
- /* Sub-Prozess erzeugen */
- pid = fork( );
- if( pid > 0 )
- {
- /* Haupt-Prozess */
- 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 )
- {
- /* Sub-Prozess */
- Log_Init_Resolver( );
- Do_ResolveAddr( Addr, s->pipe[1] );
- Log_Exit_Resolver( );
- exit( 0 );
- }
- else
- {
- /* Fehler */
- free( s );
- Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
- return 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);
}
-} /* Resolve_Addr */
+ return false;
+} /* Resolve_Name */
-GLOBAL RES_STAT *
-Resolve_Name( CHAR *Host )
+#if !defined(HAVE_GETADDRINFO) || !defined(HAVE_GETNAMEINFO)
+#if !defined(WANT_IPV6) && defined(h_errno)
+static char *
+Get_Error( int H_Error )
{
- /* Hostnamen (asyncron!) aufloesen. Bei Fehler, z.B. wenn der
- * Child-Prozess nicht erzeugt werden kann, wird NULL geliefert.
- * Der Host kann dann nicht aufgeloest werden. */
-
- RES_STAT *s;
- INT pid;
-
- /* Speicher anfordern */
- s = malloc( sizeof( RES_STAT ));
- if( ! s )
- {
- Log( LOG_EMERG, "Resolver: Can't allocate memory! [Resolve_Name]" );
- return NULL;
+ /* 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
- /* Pipe fuer Antwort initialisieren */
- if( pipe( s->pipe ) != 0 )
- {
- free( s );
- Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
- return NULL;
- }
- /* Sub-Prozess erzeugen */
- pid = fork( );
- if( pid > 0 )
- {
- /* Haupt-Prozess */
- 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 )
- {
- /* Sub-Prozess */
- Log_Init_Resolver( );
- Do_ResolveName( Host, s->pipe[1] );
- Log_Exit_Resolver( );
- exit( 0 );
- }
- else
- {
- /* Fehler */
- free( s );
- Log( LOG_CRIT, "Resolver: Can't fork: %s!", strerror( errno ));
- return NULL;
- }
-} /* Resolve_Name */
+/* Do "IDENT" (aka "AUTH") lookup and append result to resolved_addr array */
+static void
+Do_IdentQuery(int identsock, array *resolved_addr)
+{
+#ifdef IDENTAUTH
+ 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
+ (void) identsock;
+ (void) resolved_addr;
+#endif
+}
-LOCAL VOID
-Do_ResolveAddr( struct sockaddr_in *Addr, 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-Prozess: IP aufloesen und Ergebnis in Pipe schreiben. */
+ char tmp_ip_str[NG_INET_ADDRSTRLEN];
+ const char *errmsg;
+#ifdef HAVE_GETNAMEINFO
+ static const char funcname[]="getnameinfo";
+ int res;
- CHAR hostname[HOST_LEN];
- struct hostent *h;
+ *resbuf = 0;
- Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
+ res = getnameinfo((struct sockaddr *) IpAddr, ng_ipaddr_salen(IpAddr),
+ resbuf, (socklen_t)reslen, NULL, 0, NI_NAMEREQD);
+ if (res == 0)
+ return true;
- /* Namen aufloesen */
- h = gethostbyaddr( (CHAR *)&Addr->sin_addr, sizeof( Addr->sin_addr ), AF_INET );
- if( h ) strcpy( hostname, h->h_name );
+ if (res == EAI_SYSTEM)
+ errmsg = strerror(errno);
else
- {
-#ifdef h_errno
- Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\": %s!", inet_ntoa( Addr->sin_addr ), Get_Error( h_errno ));
+ errmsg = gai_strerror(res);
#else
- Log_Resolver( LOG_WARNING, "Can't resolve address \"%s\"!", inet_ntoa( Addr->sin_addr ));
-#endif
- strcpy( hostname, inet_ntoa( Addr->sin_addr ));
+ 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 */
}
+#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;
- /* Antwort an Parent schreiben */
- if( write( w_fd, hostname, strlen( hostname ) + 1 ) != ( strlen( hostname ) + 1 ))
- {
- Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
- close( w_fd );
- return;
+#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, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
-} /* Do_ResolveAddr */
+ 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;
-LOCAL VOID
-Do_ResolveName( CHAR *Host, INT w_fd )
-{
- /* Resolver Sub-Prozess: Name aufloesen und Ergebnis in Pipe schreiben. */
+ memcpy(&addr, a->ai_addr, a->ai_addrlen);
- CHAR ip[16];
- struct hostent *h;
- struct in_addr *addr;
+ if (!array_catb(IpAddr, (char *)&addr, sizeof(addr)))
+ break;
+ }
- Log_Resolver( LOG_DEBUG, "Now resolving \"%s\" ...", Host );
+ freeaddrinfo(ai_results);
+ return a == NULL;
+#else
+ struct hostent *h = gethostbyname(hostname);
- /* Namen aufloesen */
- h = gethostbyname( Host );
- if( h )
- {
- addr = (struct in_addr *)h->h_addr;
- strcpy( ip, inet_ntoa( *addr ));
- }
- else
- {
+ if (!h) {
#ifdef h_errno
- Log_Resolver( LOG_WARNING, "Can't resolve \"%s\": %s!", Host, 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 \"%s\"!", Host );
+ Log_Subprocess(LOG_WARNING, "Can't resolve \"%s\"", hostname);
#endif
- strcpy( ip, "" );
+ return false;
}
+ memset(&addr, 0, sizeof(addr));
- /* Antwort an Parent schreiben */
- if( write( w_fd, ip, strlen( ip ) + 1 ) != ( strlen( ip ) + 1 ))
- {
- Log_Resolver( LOG_CRIT, "Resolver: Can't write to parent: %s!", strerror( errno ));
- close( w_fd );
- return;
+ 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
+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--;
}
- if( ip[0] ) Log_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip );
-} /* Do_ResolveName */
+ return false;
+}
-#ifdef h_errno
+static void
+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
+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);
-LOCAL CHAR *
-Get_Error( INT H_Error )
+ 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)
{
- /* Fehlerbeschreibung fuer H_Error liefern */
-
- 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";
+ /* 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));
+ }
+ } 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;
}
-} /* Get_Error */
+ 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
+ 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
+ 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- */
projects / ngircd-alex.git / blobdiff