Rework wget, the xconnect interface, and its various clients

in order to fix the problems with round robin DNS reported
by Andrew Flegg:
    http://busybox.net/lists/busybox/2003-October/009579.html

This removes the ipv6 specific xconnect dns lookups.  I do
not see why that would need to be special cased for ipv6 as
was done, but that will just have to be tested.

So IPV6 people -- please test this change!

 -Erik

include/libbb.h

@@ -109,9 +109,9 @@ extern int is_directory(const char *name, int followLinks, struct stat *statBuf)
 extern int remove_file(const char *path, int flags);
 extern int copy_file(const char *source, const char *dest, int flags);
 extern ssize_t safe_read(int fd, void *buf, size_t count);
-extern ssize_t safe_write(int fd, void *buf, size_t count);
-extern ssize_t bb_full_write(int fd, const void *buf, size_t len);
 extern ssize_t bb_full_read(int fd, void *buf, size_t len);
+extern ssize_t safe_write(int fd, const void *buf, size_t count);
+extern ssize_t bb_full_write(int fd, const void *buf, size_t len);
 extern int recursive_action(const char *fileName, int recurse,
 	  int followLinks, int depthFirst,
 	  int (*fileAction) (const char *fileName, struct stat* statbuf, void* userData),
@@ -294,7 +294,9 @@ extern struct hostent *xgethostbyname(const char *name);
 extern struct hostent *xgethostbyname2(const char *name, int af);
 extern int create_icmp_socket(void);
 extern int create_icmp6_socket(void);
-extern int xconnect(const char *host, const char *port);
+extern int xconnect(struct sockaddr_in *s_addr);
+extern int bb_getport(char *port);
+extern void bb_lookup_host(struct sockaddr_in *s_in, char *host, char *port);
 
 //#warning wrap this?
 char *dirname (char *path);

libbb/safe_write.c

@@ -26,7 +26,7 @@
 
 
 
-ssize_t safe_write(int fd, void *buf, size_t count)
+ssize_t safe_write(int fd, const void *buf, size_t count)
 {
 	ssize_t n;
 

libbb/xconnect.c

@@ -11,69 +11,57 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <errno.h>
 #include <netdb.h>
+#include <sys/socket.h>
 #include <netinet/in.h>
+#include <arpa/inet.h>
 #include "libbb.h"
 
-int xconnect(const char *host, const char *port)
+int bb_getport(char *port)
 {
-#ifdef CONFIG_FEATURE_IPV6
+	int port_nr;
-	struct addrinfo hints;
+	char *endptr;
-	struct addrinfo *res;
-	struct addrinfo *addr_info;
-	int error;
-	int s;
-
-	memset(&hints, 0, sizeof(hints));
-	/* set-up hints structure */
-	hints.ai_family = PF_UNSPEC;
-	hints.ai_socktype = SOCK_STREAM;
-	error = getaddrinfo(host, port, &hints, &res);
-	if (error||!res)
-		bb_perror_msg_and_die(gai_strerror(error));
-	addr_info=res;
-	while (res) {
-		s=socket(res->ai_family, res->ai_socktype, res->ai_protocol);
-		if (s<0)
-		{
-			error=s;
-			res=res->ai_next;
-			continue;
-		}
-		/* try to connect() to res->ai_addr */
-		error = connect(s, res->ai_addr, res->ai_addrlen);
-		if (error >= 0)
-			break;
-		close(s);
-		res=res->ai_next;
-	}
-	freeaddrinfo(addr_info);
-	if (error < 0)
-	{
-		bb_perror_msg_and_die("Unable to connect to remote host (%s)", host);
-	}
-	return s;
-#else
-	struct sockaddr_in s_addr;
-	int s = socket(AF_INET, SOCK_STREAM, 0);
 	struct servent *tserv;
-	int port_nr=htons(atoi(port));
-	struct hostent * he;
 
-	if (port_nr==0 && (tserv = getservbyname(port, "tcp")) != NULL)
+	if (!port) {
-		port_nr = tserv->s_port;
+		return -1;
-
+	}
-	memset(&s_addr, 0, sizeof(struct sockaddr_in));
+	port_nr=strtol(port, &endptr, 10);
-	s_addr.sin_family = AF_INET;
+	if (errno != 0 || *endptr!='\0' || endptr==port || port_nr < 1 || port_nr > 65536) 
-	s_addr.sin_port = port_nr;
-
-	he = xgethostbyname(host);
-	memcpy(&s_addr.sin_addr, he->h_addr, sizeof s_addr.sin_addr);
-
-	if (connect(s, (struct sockaddr *)&s_addr, sizeof s_addr) < 0)
 	{
-		bb_perror_msg_and_die("Unable to connect to remote host (%s)", host);
+		if (port_nr==0 && (tserv = getservbyname(port, "tcp")) != NULL) {
+			port_nr = tserv->s_port;
+		} else {
+			return -1;
+		}
+	} else {
+		port_nr = htons(port_nr);
+	}
+	return port_nr;
+}
+
+void bb_lookup_host(struct sockaddr_in *s_in, char *host, char *port)
+{
+	struct hostent *he;
+
+	memset(s_in, 0, sizeof(struct sockaddr_in));
+	s_in->sin_family = AF_INET;
+	he = xgethostbyname(host);
+	memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
+
+	if (port) {
+		s_in->sin_port=bb_getport(port);
+	}
+}
+
+int xconnect(struct sockaddr_in *s_addr)
+{
+	int s = socket(AF_INET, SOCK_STREAM, 0);
+	if (connect(s, (struct sockaddr_in *)s_addr, sizeof(struct sockaddr_in)) < 0)
+	{
+		bb_perror_msg_and_die("Unable to connect to remote host (%s)", 
+				inet_ntoa(s_addr->sin_addr));
 	}
 	return s;
-#endif
 }

networking/telnet.c

@@ -573,6 +573,7 @@ extern int telnet_main(int argc, char** argv)
 	char *host;
 	char *port;
 	int len;
+	struct sockaddr_in s_in;
 #ifdef USE_POLL
 	struct pollfd ufds[2];
 #else	
@@ -601,7 +602,8 @@ extern int telnet_main(int argc, char** argv)
 	
 	host = argv[1];
 	
-	G.netfd = xconnect(host, port);
+	bb_lookup_host(&s_in, host, port);
+	G.netfd = xconnect(&s_in);
 
 	setsockopt(G.netfd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof one);
 

networking/wget.c

@@ -40,7 +40,7 @@ struct host_info {
 };
 
 static void parse_url(char *url, struct host_info *h);
-static FILE *open_socket(char *host, int port);
+static FILE *open_socket(struct sockaddr_in *s_in, int port);
 static char *gethdr(char *buf, size_t bufsiz, FILE *fp, int *istrunc);
 static int ftpcmd(char *s1, char *s2, FILE *fp, char *buf);
 
@@ -155,6 +155,7 @@ int wget_main(int argc, char **argv)
 	int extra_headers_left = sizeof(extra_headers);
 	int which_long_opt = 0, option_index = -1;
 	struct host_info server, target;
+	struct sockaddr_in s_in;
 
 	FILE *sfp = NULL;			/* socket to web/ftp server			*/
 	FILE *dfp = NULL;			/* socket to ftp server (data)		*/
@@ -290,6 +291,15 @@ int wget_main(int argc, char **argv)
 			do_continue = 0;
 	}
 
+	/* We want to do exactly _one_ DNS lookup, since some
+	 * sites (i.e. ftp.us.debian.org) use round-robin DNS
+	 * and we want to connect to only one IP... */
+	bb_lookup_host(&s_in, server.host, NULL);
+	if (quiet_flag==FALSE) {
+		fprintf(stdout, "Connecting to %s[%s]:%d\n",
+				server.host, inet_ntoa(s_in.sin_addr), server.port);
+	}
+
 	if (proxy || !target.is_ftp) {
 		/*
 		 *  HTTP session
@@ -304,7 +314,7 @@ int wget_main(int argc, char **argv)
 			 * Open socket to http server
 			 */
 			if (sfp) fclose(sfp);
-			sfp = open_socket(server.host, server.port);
+			sfp = open_socket(&s_in, server.port);
 			
 			/*
 			 * Send HTTP request.
@@ -416,7 +426,7 @@ read_response:
 		if (! target.user)
 			target.user = bb_xstrdup("anonymous:busybox@");
 
-		sfp = open_socket(server.host, server.port);
+		sfp = open_socket(&s_in, server.port);
 		if (ftpcmd(NULL, NULL, sfp, buf) != 220)
 			close_delete_and_die("%s", buf+4);
 
@@ -459,7 +469,7 @@ read_response:
 		port = atoi(s+1);
 		s = strrchr(buf, ',');
 		port += atoi(s+1) * 256;
-		dfp = open_socket(server.host, port);
+		dfp = open_socket(&s_in, port);
 
 		if (do_continue) {
 			sprintf(buf, "REST %ld", beg_range);
@@ -584,14 +594,16 @@ void parse_url(char *url, struct host_info *h)
 }
 
 
-FILE *open_socket(char *host, int port)
+FILE *open_socket(struct sockaddr_in *s_in, int port)
 {
 	int fd;
 	FILE *fp;
-	char port_str[10];
 
-	snprintf(port_str, sizeof(port_str), "%d", port);
+	if (port>0 && port < 65536) {
-	fd=xconnect(host, port_str);
+		s_in->sin_port=htons(port);
+	}
+
+	fd=xconnect(s_in);
 
 	/*
 	 * Get the server onto a stdio stream.
@@ -838,7 +850,7 @@ progressmeter(int flag)
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: wget.c,v 1.60 2003/09/15 08:33:37 andersen Exp $
+ *	$Id: wget.c,v 1.61 2003/10/31 09:31:43 andersen Exp $
  */
 
 

util-linux/rdate.c

@@ -47,17 +47,16 @@ static void socket_timeout(int sig)
 static time_t askremotedate(const char *host)
 {
 	unsigned long int nett, localt;
-	const char *port="37";
+	struct sockaddr_in addr s_in;
 	int fd;
 
-	if (getservbyname("time", "tcp") != NULL)
+	bb_lookup_host(&s_in, host, "time");
-		port="time";
 
 	/* Add a timeout for dead or non accessable servers */
 	alarm(10);
 	signal(SIGALRM, socket_timeout);
 
-	fd = xconnect(host, port);
+	fd = xconnect(s_in);
 
 	if (safe_read(fd, (void *)&nett, 4) != 4)    /* read time from server */
 		bb_error_msg_and_die("%s did not send the complete time", host);