ports/mail/isync/patches/patch-src_socket_c

Backout ec50c55c36887b86b0143a265acae4b22d117fe9 "make DNS lookup asynchronous"
doing fork(2) for async getaddrinfo(3) to avoid pledging "proc".

Index: src/socket.c
--- src/socket.c.orig
+++ src/socket.c
@@ -28,7 +28,6 @@
 #endif
 
 enum {
-	SCK_RESOLVING,
 	SCK_CONNECTING,
 #ifdef HAVE_LIBSSL
 	SCK_STARTTLS,
@@ -416,7 +415,6 @@ static void socket_fd_cb( int, void * );
 static void socket_fake_cb( void * );
 static void socket_timeout_cb( void * );
 
-static void socket_resolve( conn_t * );
 static void socket_connect_one( conn_t * );
 static void socket_connect_next( conn_t * );
 static void socket_connect_failed( conn_t * );
@@ -424,22 +422,16 @@ static void socket_connected( conn_t * );
 static void socket_connect_bail( conn_t * );
 
 static void
-socket_register_internal( conn_t *sock, int fd )
+socket_open_internal( conn_t *sock, int fd )
 {
 	sock->fd = fd;
+	fcntl( fd, F_SETFL, O_NONBLOCK );
 	init_notifier( &sock->notify, fd, socket_fd_cb, sock );
 	init_wakeup( &sock->fd_fake, socket_fake_cb, sock );
 	init_wakeup( &sock->fd_timeout, socket_timeout_cb, sock );
 }
 
 static void
-socket_open_internal( conn_t *sock, int fd )
-{
-	fcntl( fd, F_SETFL, O_NONBLOCK );
-	socket_register_internal( sock, fd );
-}
-
-static void
 socket_close_internal( conn_t *sock )
 {
 	wipe_notifier( &sock->notify );
@@ -449,6 +441,32 @@ socket_close_internal( conn_t *sock )
 	sock->fd = -1;
 }
 
+#ifndef HAVE_IPV6
+struct addr_info {
+	struct addr_info *ai_next;
+	struct sockaddr_in ai_addr[1];
+};
+
+#define freeaddrinfo(ai) free( ai )
+
+static struct addr_info *
+init_addrinfo( struct hostent *he )
+{
+	uint naddr = 0;
+	for (char **addr = he->h_addr_list; *addr; addr++)
+		naddr++;
+	struct addr_info *caddr = nfzalloc( naddr * sizeof(struct addrinfo) );
+	struct addr_info *ret, **caddrp = &ret;
+	for (char **addr = he->h_addr_list; *addr; addr++, caddr++) {
+		caddr->ai_addr->sin_family = AF_INET;
+		memcpy( &caddr->ai_addr->sin_addr.s_addr, *addr, sizeof(struct in_addr) );
+		*caddrp = caddr;
+		caddrp = &caddr->ai_next;
+	}
+	return ret;
+}
+#endif
+
 void
 socket_connect( conn_t *sock, void (*cb)( int ok, void *aux ) )
 {
@@ -483,202 +501,77 @@ socket_connect( conn_t *sock, void (*cb)( int ok, void
 		info( "\vok\n" );
 		socket_connected( sock );
 	} else {
-		socket_resolve( sock );
-	}
-}
+#ifdef HAVE_IPV6
+		int gaierr;
+		struct addrinfo hints;
 
-static void
-pipe_write( int fd, void *buf, int len )
-{
-	do {
-		int wrote = write( fd, buf, len );
-		if (wrote < 0) {
-			perror( "write" );
-			_exit( 1 );
+		memset( &hints, 0, sizeof(hints) );
+		hints.ai_family = AF_UNSPEC;
+		hints.ai_socktype = SOCK_STREAM;
+		hints.ai_flags = AI_ADDRCONFIG;
+		infon( "Resolving %s... ", conf->host );
+		if ((gaierr = getaddrinfo( conf->host, NULL, &hints, &sock->addrs ))) {
+			error( "Error: Cannot resolve server '%s': %s\n", conf->host, gai_strerror( gaierr ) );
+			socket_connect_bail( sock );
+			return;
 		}
-		buf = ((char *)buf) + wrote;
-		len -= wrote;
-	} while (len);
-}
-
-static void
-socket_resolve( conn_t *sock )
-{
-	info( "Resolving %s...\n", sock->conf->host );
-
-	int pfd[2];
-	if (pipe( pfd )) {
-		perror( "pipe" );
-		exit( 1 );
-	}
-	switch (fork()) {
-	case -1:
-		perror( "fork" );
-		exit( 1 );
-	case 0:
-		break;
-	default:
-		close( pfd[1] );
-		socket_register_internal( sock, pfd[0] );
-		sock->state = SCK_RESOLVING;
-		conf_notifier( &sock->notify, 0, POLLIN );
-		socket_expect_activity( sock, 1 );
-		return;
-	}
-
-#ifdef HAVE_IPV6
-	struct addrinfo *res, hints = { 0 };
-	hints.ai_family = AF_UNSPEC;
-	hints.ai_socktype = SOCK_STREAM;
-	hints.ai_flags = AI_ADDRCONFIG;
-	int gaierr = getaddrinfo( sock->conf->host, NULL, &hints, &res );
-	pipe_write( pfd[1], &gaierr, sizeof(gaierr) );
-	if (gaierr)
-		_exit( 1 );
-	static_assert( sizeof(((struct addrinfo){ 0 }).ai_family) == sizeof(int), "unexpected size of ai_family" );
-	static_assert( sizeof(struct in_addr) % sizeof(int) == 0, "unexpected size of struct in_addr" );
-	static_assert( sizeof(struct in6_addr) % sizeof(int) == 0, "unexpected size of struct in6_addr" );
-	int nbytes = 0;
-	for (struct addrinfo *cres = res; cres; cres = cres->ai_next) {
-		if (cres->ai_family == AF_INET) {
-			nbytes += sizeof(int) + sizeof(struct in_addr);
-		} else {
-			assert( cres->ai_family == AF_INET6 );
-			nbytes += sizeof(int) + sizeof(struct in6_addr);
-		}
-	}
-	pipe_write( pfd[1], &nbytes, sizeof(nbytes) );
-	for (struct addrinfo *cres = res; cres; cres = cres->ai_next) {
-		pipe_write( pfd[1], &cres->ai_family, sizeof(int) );
-		if (cres->ai_family == AF_INET)
-			pipe_write( pfd[1], &((struct sockaddr_in *)cres->ai_addr)->sin_addr, sizeof(struct in_addr) );
-		else
-			pipe_write( pfd[1], &((struct sockaddr_in6 *)cres->ai_addr)->sin6_addr, sizeof(struct in6_addr) );
-	}
+		info( "\vok\n" );
 #else
-	struct hostent *he = gethostbyname( sock->conf->host );
-	int herrno = he ? 0 : h_errno;
-	pipe_write( pfd[1], &herrno, sizeof(herrno) );
-	if (!he)
-		_exit( 1 );
-	static_assert( sizeof(struct in_addr) % sizeof(int) == 0, "unexpected size of struct in_addr" );
-	int nbytes = 0;
-	for (char **addr = he->h_addr_list; *addr; addr++)
-		nbytes += sizeof(struct in_addr);
-	pipe_write( pfd[1], &nbytes, sizeof(nbytes) );
-	for (char **addr = he->h_addr_list; *addr; addr++)
-		pipe_write( pfd[1], *addr, sizeof(struct in_addr) );
-#endif
-	_exit( 0 );
-}
+		struct hostent *he;
 
-static void
-pipe_read( int fd, void *buf, int len )
-{
-	do {
-		int didrd = read( fd, buf, len );
-		if (didrd < 0) {
-			sys_error( "read" );
-			exit( 1 );
+		infon( "Resolving %s... ", conf->host );
+		he = gethostbyname( conf->host );
+		if (!he) {
+			error( "Error: Cannot resolve server '%s': %s\n", conf->host, hstrerror( h_errno ) );
+			socket_connect_bail( sock );
+			return;
 		}
-		if (!didrd) {
-			error( "read: unexpected EOF\n" );
-			exit( 1 );
-		}
-		buf = ((char *)buf) + didrd;
-		len -= didrd;
-	} while (len);
-}
+		info( "\vok\n" );
 
-static void
-socket_resolve_finalize( conn_t *sock )
-{
-	int errcode;
-	pipe_read( sock->fd, &errcode, sizeof(errcode) );
-	if (errcode) {
-#ifdef HAVE_IPV6
-		const char *err = gai_strerror( errcode );
-#else
-		const char *err = hstrerror( errcode );
+		sock->addrs = init_addrinfo( he );
 #endif
-		error( "Error: Cannot resolve server '%s': %s\n", sock->conf->host, err );
-		socket_close_internal( sock );
-		socket_connect_bail( sock );
-		return;
+		sock->curr_addr = sock->addrs;
+		socket_connect_one( sock );
 	}
-
-	int nbytes;
-	pipe_read( sock->fd, &nbytes, sizeof(nbytes) );
-	char *addrs = nfmalloc( nbytes );
-	pipe_read( sock->fd, addrs, nbytes );
-	sock->curr_addr = sock->addrs = addrs;
-	sock->addrs_end = addrs + nbytes;
-	socket_close_internal( sock );  // Get rid of the pipe
-	socket_connect_one( sock );
 }
 
 static void
-socket_resolve_timeout( conn_t *sock )
-{
-	error( "Error: Cannot resolve server '%s': timeout.\n", sock->conf->host );
-	socket_close_internal( sock );
-	socket_connect_bail( sock );
-}
-
-static void
 socket_connect_one( conn_t *sock )
 {
-	char *ai = sock->curr_addr;
-	if (ai == sock->addrs_end) {
+	int s;
+#ifdef HAVE_IPV6
+	struct addrinfo *ai;
+#else
+	struct addr_info *ai;
+#endif
+
+	if (!(ai = sock->curr_addr)) {
 		error( "No working address found for %s\n", sock->conf->host );
 		socket_connect_bail( sock );
 		return;
 	}
 
-	union {
-		struct sockaddr any;
-		struct sockaddr_in ip4;
 #ifdef HAVE_IPV6
-		struct sockaddr_in6 ip6;
-#endif
-	} addr;
-
-#ifdef HAVE_IPV6
-	int fam = *(int *)ai;
-	ai += sizeof(int);
-	int addr_len;
-	if (fam == AF_INET6) {
-		addr_len = sizeof(addr.ip6);
-		addr.ip6.sin6_addr = *(struct in6_addr *)ai;
-		addr.ip6.sin6_flowinfo = 0;
-		addr.ip6.sin6_scope_id = 0;
-		ai += sizeof(struct in6_addr);
-	} else {
-		addr_len = sizeof(addr.ip4);
-#else
-	const int fam = AF_INET;
-	const int addr_len = sizeof(addr.ip4);
-	{
-#endif
-		addr.ip4.sin_addr = *(struct in_addr *)ai;
-		ai += sizeof(struct in_addr);
-	}
-	sock->curr_addr = ai;
-
-#ifdef HAVE_IPV6
-	if (fam == AF_INET6) {
+	if (ai->ai_family == AF_INET6) {
+		struct sockaddr_in6 *in6 = ((struct sockaddr_in6 *)ai->ai_addr);
 		char sockname[64];
-		inet_ntop( fam, &addr.ip6.sin6_addr, sockname, sizeof(sockname) );
+		in6->sin6_port = htons( sock->conf->port );
 		nfasprintf( &sock->name, "%s ([%s]:%hu)",
-		            sock->conf->host, sockname, sock->conf->port );
+		            sock->conf->host, inet_ntop( AF_INET6, &in6->sin6_addr, sockname, sizeof(sockname) ), sock->conf->port );
 	} else
 #endif
 	{
+		struct sockaddr_in *in = ((struct sockaddr_in *)ai->ai_addr);
+		in->sin_port = htons( sock->conf->port );
 		nfasprintf( &sock->name, "%s (%s:%hu)",
-		            sock->conf->host, inet_ntoa( addr.ip4.sin_addr ), sock->conf->port );
+		            sock->conf->host, inet_ntoa( in->sin_addr ), sock->conf->port );
 	}
 
-	int s = socket( fam, SOCK_STREAM, 0 );
+#ifdef HAVE_IPV6
+	s = socket( ai->ai_family, SOCK_STREAM, 0 );
+#else
+	s = socket( PF_INET, SOCK_STREAM, 0 );
+#endif
 	if (s < 0) {
 		socket_connect_next( sock );
 		return;
@@ -686,9 +579,11 @@ socket_connect_one( conn_t *sock )
 	socket_open_internal( sock, s );
 
 	infon( "Connecting to %s... ", sock->name );
-	addr.any.sa_family = fam;
-	addr.ip4.sin_port = htons( sock->conf->port );  // Aliased for ip6
-	if (connect( s, &addr.any, addr_len )) {
+#ifdef HAVE_IPV6
+	if (connect( s, ai->ai_addr, ai->ai_addrlen )) {
+#else
+	if (connect( s, ai->ai_addr, sizeof(*ai->ai_addr) )) {
+#endif
 		if (errno != EINPROGRESS) {
 			socket_connect_failed( sock );
 			return;
@@ -709,6 +604,7 @@ socket_connect_next( conn_t *conn )
 	sys_error( "Cannot connect to %s", conn->name );
 	free( conn->name );
 	conn->name = NULL;
+	conn->curr_addr = conn->curr_addr->ai_next;
 	socket_connect_one( conn );
 }
 
@@ -722,8 +618,10 @@ socket_connect_failed( conn_t *conn )
 static void
 socket_connected( conn_t *conn )
 {
-	free( conn->addrs );
-	conn->addrs = NULL;
+	if (conn->addrs) {
+		freeaddrinfo( conn->addrs );
+		conn->addrs = NULL;
+	}
 	conf_notifier( &conn->notify, 0, POLLIN );
 	socket_expect_activity( conn, 0 );
 	conn->state = SCK_READY;
@@ -733,8 +631,10 @@ socket_connected( conn_t *conn )
 static void
 socket_cleanup_names( conn_t *conn )
 {
-	free( conn->addrs );
-	conn->addrs = NULL;
+	if (conn->addrs) {
+		freeaddrinfo( conn->addrs );
+		conn->addrs = NULL;
+	}
 	free( conn->name );
 	conn->name = NULL;
 }
@@ -1208,11 +1108,6 @@ socket_fd_cb( int events, void *aux )
 {
 	conn_t *conn = (conn_t *)aux;
 
-	if (conn->state == SCK_RESOLVING) {
-		socket_resolve_finalize( conn );
-		return;
-	}
-
 	if ((events & POLLERR) || conn->state == SCK_CONNECTING) {
 		int soerr;
 		socklen_t selen = sizeof(soerr);
@@ -1275,9 +1170,7 @@ socket_timeout_cb( void *aux )
 {
 	conn_t *conn = (conn_t *)aux;
 
-	if (conn->state == SCK_RESOLVING) {
-		socket_resolve_timeout( conn );
-	} else if (conn->state == SCK_CONNECTING) {
+	if (conn->state == SCK_CONNECTING) {
 		errno = ETIMEDOUT;
 		socket_connect_failed( conn );
 	} else {