#include "portab.h"
-static char UNUSED id[] = "$Id: resolve.c,v 1.23 2006/02/08 15:24:10 fw Exp $";
+static char UNUSED id[] = "$Id: resolve.c,v 1.29 2008/02/26 22:04:17 fw Exp $";
#include "imp.h"
#include <assert.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
-#include <arpa/inet.h>
#include <netdb.h>
#ifdef IDENTAUTH
#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
+static pid_t
Resolver_fork(int *pipefds)
{
- int pid;
+ pid_t pid;
+
if (pipe(pipefds) != 0) {
Log( LOG_ALERT, "Resolver: Can't create output pipe: %s!", strerror( errno ));
return -1;
}
+/**
+ * Resolve IP (asynchronous!).
+ */
GLOBAL bool
-Resolve_Addr( RES_STAT *s, struct sockaddr_in *Addr, int identsock, void (*cbfunc)(int, short))
+Resolve_Addr(RES_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);
if (pid > 0) {
-#ifdef DEBUG
- Log( LOG_DEBUG, "Resolver for %s created (PID %d).", inet_ntoa( Addr->sin_addr ), pid );
-#endif
+ Log(LOG_DEBUG, "Resolver for %s created (PID %d).", ng_ipaddr_tostr(Addr), pid);
+
s->pid = pid;
s->resolver_fd = pipefd[0];
return register_callback(s, cbfunc);
} /* Resolve_Addr */
+/**
+ * Resolve hostname (asynchronous!).
+ */
GLOBAL bool
Resolve_Name( RES_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);
}
-static void
-Do_ResolveAddr( struct sockaddr_in *Addr, int identsock, int w_fd )
+#ifndef WANT_IPV6
+#ifdef h_errno
+static char *
+Get_Error( int H_Error )
{
- /* Resolver sub-process: resolve IP address and write result into
- * pipe to parent. */
+ /* 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 /* h_errno */
+#endif /* WANT_IPV6 */
- char hostname[HOST_LEN];
- char ipstr[HOST_LEN];
- struct hostent *h;
- size_t len;
- struct in_addr *addr;
- char *ntoaptr;
- array resolved_addr;
+
+/* 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_Resolver(LOG_DEBUG, "Doing IDENT lookup on socket %d ...", identsock);
#endif
- array_init(&resolved_addr);
- /* Resolve IP address */
+ res = ident_id( identsock, 10 );
#ifdef DEBUG
- Log_Resolver( LOG_DEBUG, "Now resolving %s ...", inet_ntoa( Addr->sin_addr ));
+ Log_Resolver(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"",
+ identsock, res ? res : "(NULL)" );
#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 ));
+ if (!res) /* no result */
+ return;
+ if (!array_cats(resolved_addr, res))
+ Log_Resolver(LOG_WARNING, "Resolver: Cannot copy IDENT result: %s!", strerror(errno));
+
+ free(res);
+#else
+ (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
+ * @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)
+{
+ 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, reslen, NULL, 0, NI_NAMEREQD);
+ if (res == 0)
+ return true;
+
+ if (res == EAI_SYSTEM)
+ errmsg = strerror(errno);
+ else
+ errmsg = gai_strerror(res);
#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 ));
+ 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 {
- 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);
- }
+# ifdef h_errno
+ errmsg = Get_Error(h_errno);
+# else
+ errmsg = "unknown error";
+# endif /* h_errno */
}
- Log_Resolver( LOG_DEBUG, "Ok, translated %s to \"%s\".", inet_ntoa( Addr->sin_addr ), hostname );
+#endif /* HAVE_GETNAMEINFO */
- 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 );
- return;
- }
+ assert(errmsg);
+ assert(reslen >= NG_INET_ADDRSTRLEN);
+ ng_ipaddr_tostr_r(IpAddr, tmp_ip_str);
-#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_Resolver(LOG_WARNING, "%s: Can't resolve address \"%s\": %s",
+ funcname, tmp_ip_str, errmsg);
+ 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)
+{
+ ng_ipaddr_t addr;
+
+#ifdef HAVE_GETADDRINFO
+ int res;
+ struct addrinfo *a, *ai_results;
+ static struct addrinfo hints;
+
+#ifndef WANT_IPV6
+ hints.ai_family = AF_INET;
#endif
- res = ident_id( identsock, 10 );
-#ifdef DEBUG
- Log_Resolver(LOG_DEBUG, "Ok, IDENT lookup on socket %d done: \"%s\"",
- identsock, res ? res : "(NULL)" );
+#ifdef AI_ADDRCONFIG /* glibc has this, but not e.g. netbsd 4.0 */
+ hints.ai_flags = AI_ADDRCONFIG;
#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 */
- }
+ hints.ai_socktype = SOCK_STREAM;
+ hints.ai_protocol = IPPROTO_TCP;
+
+#ifdef WANT_IPV6
+ assert(Conf_ConnectIPv6 || Conf_ConnectIPv4);
- if (res) free(res);
+ if (!Conf_ConnectIPv6)
+ hints.ai_family = AF_INET;
+ if (!Conf_ConnectIPv4)
+ hints.ai_family = AF_INET6;
+#endif
+ res = getaddrinfo(hostname, NULL, &hints, &ai_results);
+ switch (res) {
+ case 0: break;
+ case EAI_SYSTEM:
+ Log_Resolver(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, strerror(errno));
+ return false;
+ default:
+ Log_Resolver(LOG_WARNING, "Can't resolve \"%s\": %s", hostname, gai_strerror(res));
+ return false;
+ }
+
+ for (a = ai_results; a != NULL; a = a->ai_next) {
+ assert(a->ai_addrlen <= sizeof(addr));
+
+ if (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 \"%s\": %s", hostname, Get_Error(h_errno));
#else
- (void)identsock;
+ Log_Resolver(LOG_WARNING, "Can't resolve \"%s\"", hostname);
#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 ));
+ return false;
+ }
+ memset(&addr, 0, sizeof(addr));
- close(w_fd);
- array_free(&resolved_addr);
-} /* Do_ResolveAddr */
+ 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_Resolver(LOG_WARNING, "Address mismatch: %s != %s",
+ tmp_ip_str, ng_ipaddr_tostr(tmpAddrs));
+ tmpAddrs++;
+ len--;
+ }
+
+ return false;
+}
static void
-Do_ResolveName( const char *Host, int w_fd )
+Log_Forgery_NoIP(const char *ip, const char *host)
{
- /* Resolver sub-process: resolve name and write result into pipe
- * to parent. */
+ Log_Resolver(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;
- int len;
+static void
+Log_Forgery_WrongIP(const char *ip, const char *host)
+{
+ Log_Resolver(LOG_WARNING,"Possible forgery: %s resolved to %s "
+ "(which points to 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_Resolver( 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_Resolver(LOG_DEBUG, "Now resolving %s ...", tmp_ip_str);
#endif
- close(w_fd);
- return;
+ if (!ReverseLookup(Addr, hostname, sizeof(hostname)))
+ goto dns_done;
+
+ if (ForwardLookup(hostname, &resolved_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_Resolver( LOG_DEBUG, "Ok, translated \"%s\" to %s.", Host, ip );
+ Log_Resolver(LOG_DEBUG, "Ok, translated %s to \"%s\".", tmp_ip_str, hostname);
#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 );
+ dns_done:
+ len = strlen(hostname);
+ hostname[len] = '\n';
+ if (!array_copyb(&resolved_addr, hostname, ++len)) {
+ Log_Resolver(LOG_CRIT, "Resolver: Can't copy resolved name: %s!", strerror(errno));
+ array_free(&resolved_addr);
+ return;
}
-} /* Do_ResolveName */
+ Do_IdentQuery(identsock, &resolved_addr);
-#ifdef h_errno
+ ArrayWrite(w_fd, &resolved_addr);
-static char *
-Get_Error( int H_Error )
+ array_free(&resolved_addr);
+} /* Do_ResolveAddr */
+
+
+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;
+#ifdef DEBUG
+ ng_ipaddr_t *addr;
+ size_t len;
+#endif
+ Log_Resolver(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";
+ array_init(&IpAddrs);
+ /* Resolve hostname */
+ if (!ForwardLookup(Host, &IpAddrs)) {
+ 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_Resolver(LOG_DEBUG, "translated \"%s\" to %s.",
+ Host, ng_ipaddr_tostr(addr));
}
-} /* Get_Error */
-
#endif
+ /* Write result into pipe to parent */
+ ArrayWrite(w_fd, &IpAddrs);
+
+ array_free(&IpAddrs);
+} /* Do_ResolveName */
static bool
register_callback( RES_STAT *s, void (*cbfunc)(int, short))
{
- assert(cbfunc);
+ assert(cbfunc != NULL);
assert(s != NULL);
assert(s->resolver_fd >= 0);
return true;
Log( LOG_CRIT, "Resolver: Could not register callback function: %s!", strerror(errno));
- Resolve_Shutdown(s);
+ close(s->resolver_fd);
+ Resolve_Init(s);
return false;
}
return ret;
}
-
+
+/**
+ * Read result of resolver sub-process from pipe
+ */
GLOBAL size_t
Resolve_Read( RES_STAT *s, void* readbuf, size_t buflen)
{
- /* Read result of resolver sub-process from pipe */
- int err, bytes_read;
+ ssize_t 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;
+ if (errno == EAGAIN)
return 0;
- }
- return 0;
- }
- Resolve_Shutdown(s);
- if (bytes_read == 0) { /* EOF: lookup failed */
+ Log( LOG_CRIT, "Resolver: Can't read result: %s!", strerror(errno));
+ bytes_read = 0;
+ }
#ifdef DEBUG
+ else if (bytes_read == 0)
Log( LOG_DEBUG, "Resolver: Can't read result: EOF");
#endif
- return 0;
- }
-
- return bytes_read;
+ Resolve_Shutdown(s);
+ return (size_t)bytes_read;
}
/* -eof- */
projects / ngircd-alex.git / blobdiff