Introduce functions for sending requests

* Makefile: Add io.c
* io.c: New file.
* nsu.h (nsu_sockaddr): New data type.
(nsu_nsend): New proto.
* main.c (send_update_query): Use nsu_nsend instead of res_nsend.

5 files changed, 304 insertions, 28 deletions

diff --git a/.gitignore b/.gitignore
index c2eed98..c05a9c9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 nsu
 tmp/
 .gdbinit
+TAGS
 TODO
 core
 lex.yy.c
diff --git a/Makefile b/Makefile
index f9bb6c8..bc27076 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@ CFLAGS=-ggdb
 APPSRC=main.c y.tab.c lex.yy.c
 APPOBJ=${APPSRC:.c=.o}
 
-NSUSRC=nsu.c typestr.c alg.c log.c
+NSUSRC=nsu.c typestr.c alg.c log.c io.c
 NSUOBJ=${NSUSRC:.c=.o}
 
 OBJS=$(NSUOBJ) $(APPOBJ)
@@ -27,3 +27,8 @@ clean:
 allclean: clean
 	rm -f lex.yy.c y.tab.c y.tab.h
 
+ETAGS     = etags
+ETAGSFLAGS=
+
+tags:
+	$(ETAGS) $(ETAGSFLAGS) $(NSUSRC) main.c grammar.y lexer.l
diff --git a/io.c b/io.c
new file mode 100644
index 0000000..09654f1
--- /dev/null
+++ b/io.c
@@ -0,0 +1,218 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <poll.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "nsu.h"
+
+static int
+nsu_nsend_dg(res_state statp, nsu_sockaddr *a, u_char *qbuf, size_t qlen,
+	     u_char *rbuf, size_t rlen, size_t *return_len)
+{
+	struct pollfd pfd;
+	UPDATE_HEADER *uhp;
+	int retry = 0;
+	int result = NSU_SEND_SYSERR;
+	int ec;
+
+	nsu_log(NSU_LOG_DEBUG, "sending query %d via UDP",
+		((HEADER*)qbuf)->id);
+	pfd.fd = socket(a->addr.sa.sa_family, SOCK_DGRAM, 0);
+	if (pfd.fd == -1) {
+		return NSU_SEND_SYSERR;
+	}
+	pfd.events = POLLOUT;
+	while (1) {
+		ssize_t n;
+		int rc;
+		
+		rc = poll(&pfd, 1, statp->retrans * 1000);
+		if (rc < 0) {
+			result = NSU_SEND_SYSERR;
+			break;
+		}
+		if (rc == 0) {
+			if (retry == statp->retry) {
+				result = NSU_SEND_TIMEOUT;
+				break;
+			}
+			retry++;
+			continue;
+		}
+		if (pfd.revents & POLLOUT) {
+			n = sendto(pfd.fd, qbuf, qlen, MSG_NOSIGNAL,
+				   &a->addr.sa, a->len);
+			if (n < 0) {
+				if (errno == EINTR || errno == EAGAIN) {
+					continue;
+				}
+				result = NSU_SEND_SYSERR;
+				break;
+			}
+			pfd.events = POLLIN;
+		} else if (pfd.revents & POLLIN) {
+			nsu_sockaddr fromaddr;
+			HEADER *hp;
+
+			fromaddr.len = sizeof(fromaddr.addr);
+			n = recvfrom(pfd.fd, rbuf, rlen, 0,
+				     &fromaddr.addr.sa, &fromaddr.len);
+			if (n < 0) {
+				if (errno == EINTR || errno == EAGAIN) {
+					continue;
+				}
+				result = NSU_SEND_SYSERR;
+				break;
+			}
+			pfd.events = 0;
+			if (!(statp->options & RES_INSECURE1) &&
+			    !(fromaddr.len == a->len &&
+			      memcmp(&fromaddr.addr, &a->addr, a->len) == 0)) {
+				nsu_log(NSU_LOG_DEBUG, "%s",
+					"response from the wrong server");
+				//FIXME
+				result = NSU_SEND_BADSERV;
+				break;
+			}
+
+			hp = (HEADER*)rbuf;
+			if (hp->tc) {
+				result = NSU_SEND_RETRYTCP;
+				break;
+			}
+			*return_len = n;
+			result = NSU_SEND_OK;
+			break;
+		} else if (pfd.revents & POLLERR) {
+			result = NSU_SEND_SYSERR;
+			break;
+		} else if (pfd.revents & POLLHUP) {
+			result = NSU_SEND_PEERCLOSE;
+			break;
+		} else if (pfd.revents & POLLNVAL) {
+			result = NSU_SEND_SYSERR;
+			errno = EINVAL;
+			break;
+		} else
+			abort();
+	}
+
+	if (result == NSU_SEND_SYSERR)
+		ec = errno;
+	close(pfd.fd);
+	if (result == NSU_SEND_SYSERR)
+		errno = ec;
+	
+	return result;
+}
+
+static int
+nsu_nsend_vc(res_state statp, nsu_sockaddr *a, u_char *qbuf, size_t qlen,
+	     u_char *rbuf, size_t rlen, size_t *return_len)
+{
+	struct pollfd pfd;
+	int retry = 0;
+	int result = NSU_SEND_SYSERR;
+	int ec;
+	
+	nsu_log(NSU_LOG_DEBUG, "sending query %d via TCP",
+		((HEADER*)qbuf)->id);
+	pfd.fd = socket(a->addr.sa.sa_family, SOCK_STREAM, 0);
+	if (pfd.fd == -1) {
+		return NSU_SEND_SYSERR;
+	}
+	pfd.events = POLLOUT;
+
+	if (connect(pfd.fd, &a->addr.sa, a->len)) {
+		ec = errno;
+		close(pfd.fd);
+		errno = ec;
+		return NSU_SEND_SYSERR;
+	}
+
+	//FIXME: bind?
+	
+	while (1) {
+		ssize_t n;
+		int rc;
+		
+		rc = poll(&pfd, 1, statp->retrans * 1000);
+		if (rc < 0) {
+			result = NSU_SEND_SYSERR;
+			break;
+		}
+		if (rc == 0) {
+			if (retry == statp->retry) {
+				result = NSU_SEND_TIMEOUT;
+				break;
+			}
+			retry++;
+			continue;
+		}
+		if (pfd.revents & POLLOUT) {
+			n = write(pfd.fd, qbuf, qlen);
+			if (n < 0) {
+				if (errno == EINTR || errno == EAGAIN) {
+					continue;
+				}
+				result = NSU_SEND_SYSERR;
+				break;
+			}
+			pfd.events = POLLIN;
+		} else if (pfd.revents & POLLIN) {
+			n = read(pfd.fd, rbuf, rlen);
+			if (n < 0) {
+				if (errno == EINTR || errno == EAGAIN) {
+					continue;
+				}
+				result = NSU_SEND_SYSERR;
+				break;
+			}
+			*return_len = n;
+			result = NSU_SEND_OK;
+			break;
+		} else if (pfd.revents & POLLERR) {
+			result = NSU_SEND_SYSERR;
+			break;
+		} else if (pfd.revents & POLLHUP) {
+			result = NSU_SEND_PEERCLOSE;
+			break;
+		} else if (pfd.revents & POLLNVAL) {
+			result = NSU_SEND_SYSERR;
+			errno = EINVAL;
+			break;
+		} else
+			abort();
+	}
+
+	if (result == NSU_SEND_SYSERR)
+		ec = errno;
+	close(pfd.fd);
+	if (result == NSU_SEND_SYSERR)
+		errno = ec;
+	
+	return result;
+}
+
+int
+nsu_nsend(res_state statp, nsu_sockaddr *a, u_char *qbuf, size_t qlen,
+	  u_char *rbuf, size_t rlen, size_t *return_len)
+{
+	int result;
+	
+	if (!qbuf || !rbuf || qlen < sizeof(UPDATE_HEADER) || rlen < sizeof(UPDATE_HEADER)) {
+		errno = EINVAL;
+		return NSU_SEND_SYSERR;
+	}
+
+	result = nsu_nsend_dg(statp, a, qbuf, qlen, rbuf, rlen, return_len);
+	if (result == NSU_SEND_RETRYTCP && (statp->options & RES_USEVC))
+		result = nsu_nsend_vc(statp, a, qbuf, qlen, rbuf, rlen, return_len);
+
+	return result;
+}
+
+	
diff --git a/main.c b/main.c
index 6524685..5c95cef 100644
--- a/main.c
+++ b/main.c
@@ -411,38 +411,70 @@ enum {
 	update_retry
 };
 
+static char const *
+nsu_sockaddr_str(nsu_sockaddr *nsa, char *name, size_t namelen)
+{
+	getnameinfo(&nsa->addr.sa, nsa->len,
+		    name, namelen,
+		    NULL, 0,
+		    NI_NUMERICHOST);
+	return name;
+}
+
 int
-send_update_query(res_state state, char const *zone, u_char *qbuf, int qlen)
+send_update_query(res_state state, nsu_sockaddr *nsa,
+		  char const *zone, u_char *qbuf, int qlen)
 {
 	union {
 		UPDATE_HEADER hdr;
-		u_char buf[NS_PACKETSZ*2];
+		u_char buf[NS_PACKETSZ];
 	} response;
-	int rlen;
+	size_t rlen;
 	ns_msg handle;
 	int rcode;
+	char name[NS_MAXDNAME];
+	char const *nsname = NULL;
+	int rc;
 	
 	if (nsu_log_enabled(NSU_LOG_DEBUG) || state->options & RES_DEBUG) {
-		char name[NS_MAXDNAME];
-		
-		getnameinfo((struct sockaddr*)state->nsaddr_list,
-			    sizeof(state->nsaddr_list[0]),
-			    name, sizeof(name),
-			    NULL, 0,
-			    NI_NUMERICHOST);
+		nsname = nsu_sockaddr_str(nsa, name, sizeof(name));
 		nsu_log_msg(NSU_LOG_DEBUG, "trying nameserver %s", name);
 	}
 
-	rlen = res_nsend(state, qbuf, qlen,
-			 (u_char *) &response,
-			 sizeof(response));
-	
-	if (rlen < 0) {
-		if (errno == ECONNREFUSED) {	/* no server on the host */
-			panic("connection refused");
-		} else {
-			/* anything else: no response */
-			panic("no response");
+	rc = nsu_nsend(state, nsa, qbuf, qlen,
+		       (u_char *) &response,
+		       sizeof(response),
+		       &rlen);
+
+	if (rc == NSU_SEND_OK) {
+		
+	} else {
+		if (!nsname)
+			nsname = nsu_sockaddr_str(nsa, name, sizeof(name));
+		switch (rc) {
+		case NSU_SEND_SYSERR:
+			panic("%s: can't send: %s", nsname, strerror(errno));
+			break;
+				
+		case NSU_SEND_TIMEOUT:
+			panic("%s: server timeout", nsname);
+			break;
+
+		case NSU_SEND_BADSERV:
+			panic("%s: response from another server", nsname);
+			break;
+			
+		case NSU_SEND_RETRYTCP:
+			panic("%s: response too long; retry using TCP",
+			      nsname);
+			break;
+			
+		case NSU_SEND_PEERCLOSE:
+			panic("%s: server closed connection", nsname);
+			break;
+
+		default:
+			abort();
 		}
 		return update_fail;
 	}
@@ -471,9 +503,8 @@ send_update_query(res_state state, char const *zone, u_char *qbuf, int qlen)
 		if (nsu_log_enabled(NSU_LOG_DEBUG)
 		    || state->options & RES_DEBUG) {
 			char name[NS_MAXDNAME];
-
-			getnameinfo((struct sockaddr*)state->nsaddr_list,
-				    sizeof(state->nsaddr_list[0]),
+			
+			getnameinfo(&nsa->addr.sa, nsa->len,
 				    name, sizeof(name),
 				    NULL, 0,
 				    NI_NUMERICHOST);
@@ -504,6 +535,7 @@ run_update(nsu_rr *prereq, int num_prereq,
 	int rc;
 	int i;
 	struct __res_state rstate;
+	nsu_sockaddr addr;
 	
 	if (!domain_name) {
 		char *p = update->name;
@@ -546,11 +578,10 @@ run_update(nsu_rr *prereq, int num_prereq,
 
 
 	res_ninit(&rstate);
-	rstate.nscount = 1;
+	addr.len = sizeof(struct sockaddr_in);
 	for (i = 0; i < nscount; i++) {
-		memcpy(&rstate.nsaddr_list[0], nstab + i,
-		       sizeof(rstate.nsaddr_list[0]));
-		rc = send_update_query(&rstate, zone, query.buf, qlen);
+		memcpy(&addr.addr, &nstab[i],  sizeof(nstab[0]));
+		rc = send_update_query(&rstate, &addr, zone, query.buf, qlen);
 		if (rc != update_retry)
 			break;
 	}
diff --git a/nsu.h b/nsu.h
index 2016266..57a182c 100644
--- a/nsu.h
+++ b/nsu.h
@@ -177,6 +177,27 @@ int nsu_keyfile_private_read(char const *filename,
 			     uint8_t **pkey, size_t *pkey_len);
 
 int nsu_keyfile_read(char const *name, struct nsu_tsig **ptsig);
+
+typedef struct {
+	socklen_t len;
+	union {
+		struct sockaddr sa;
+		struct sockaddr_in in4;
+		struct sockaddr_in6 in6;
+	} addr;
+} nsu_sockaddr;
+
+enum {
+	NSU_SEND_OK,
+	NSU_SEND_SYSERR,
+	NSU_SEND_TIMEOUT,
+	NSU_SEND_BADSERV,
+	NSU_SEND_RETRYTCP,
+	NSU_SEND_PEERCLOSE
+};
+
+int nsu_nsend(res_state statp, nsu_sockaddr *a, u_char *qbuf, size_t qlen,
+	      u_char *rbuf, size_t rlen, size_t *return_len);