wdvi

commit e5ebcb757186de5f37aafe2edaa2c307d51cdfac
parent 7eb039cfdfb21c74b51e97db80ffe45b1bd703a6
Author: Kyle Milz <krwmilz@gmail.com>
Date:   Tue,  7 Sep 2021 16:43:35 +0000

two improvements for network code

First, use getaddrinfo() instead of gethostent() for DNS resolving as
it seems to work better, and i think we pick up IPv6 support for free.

Second, support DVI fetches larger than 16kb, the default openssl record
size.

Diffstat:
M
http.c
 | 
103
+++++++++++++++++++++++++++++++++++++++++++++++--------------------------------
M
http.h
 | 
2
+-

2 files changed, 62 insertions(+), 43 deletions(-)
diff --git a/http.c b/http.c
@@ -14,15 +14,13 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#include <sys/types.h>
 #include <sys/socket.h>		/* connect(), socket() */
 
-#include <arpa/inet.h>		/* inet_ntoa() */
-#include <netdb.h>		/* gethostbyname() */
-#include <netinet/in.h>		/* struct sockaddr_in */
+#include <netdb.h>		/* getaddrinfo() */
 
 #include <assert.h>
 #include <err.h>		/* err() */
-#include <stdio.h>		/* sscanf, fmemopen */
 #include <stdlib.h>		/* strtonum() */
 #include <unistd.h>		/* close() */
 
@@ -123,7 +121,8 @@ parse_url(const char dest_url[])
 
 /*
  * Takes a struct url and resolves the url hostname. Then tries connecting to
- * the url hostname using the url port.
+ * the url hostname using "https" service port. This should be modified to
+ * use url->port.
  *
  * On success return an open socket represented by a non negative integer or
  * -1 on failure.
@@ -131,34 +130,45 @@ parse_url(const char dest_url[])
 static int
 xconnect(struct url *url)
 {
-	struct hostent		*host;
-	int 			 sockfd;
-	struct sockaddr_in	 dest_addr;
-
-	if ((host = gethostbyname(url->hostname)) == NULL) {
-		warning_popup_long("%s: %s", "OK", NULL, url->hostname,
-		                   hstrerror(h_errno));
-		return -1;
-	}
-
-	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
-		err(1, "socket");
-
-	dest_addr.sin_family = AF_INET;
-	dest_addr.sin_port = htons(url->port);
-	dest_addr.sin_addr.s_addr = *(long *)(host->h_addr);
+	struct addrinfo hints, *res, *res0;
+	int error;
+	int save_errno;
+	int s;
+	const char *cause = NULL;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = AF_UNSPEC;
+	hints.ai_socktype = SOCK_STREAM;
+
+	error = getaddrinfo(url->hostname, "https", &hints, &res0);
+	if (error)
+		errx(1, "%s", gai_strerror(error));
+
+	s = -1;
+	for (res = res0; res; res = res->ai_next) {
+		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+		if (s == -1) {
+			cause = "socket";
+			continue;
+		}
 
-	memset(&(dest_addr.sin_zero), '\0', 8);
+		if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
+			cause = "connect";
+			save_errno = errno;
+			close(s);
+			errno = save_errno;
+			s = -1;
+			continue;
+		}
 
-	if (connect(sockfd, (struct sockaddr *) &dest_addr,
-	    sizeof(struct sockaddr)) == -1) {
-		warning_popup_long("%s:%i: %s", "OK", NULL,
-		                   url->hostname, url->port, strerror(errno));
-		close(sockfd);
-		return -1;
+		/* connect() succeeded */
+		break;
 	}
+	if (s == -1)
+		err(1, "%s", cause);
+	freeaddrinfo(res0);
 
-	return sockfd;
+	return s;
 }
 
 
@@ -349,7 +359,8 @@ read_response(SSL *tls, struct url *url)
 {
 	char			*buf;
 	struct http_headers	*response;
-	int			 nbytes;
+	int			 nbytes = 0;
+	int			 total_bytes = 0;
 	FILE			*dvi_file = NULL;
 
 	/* This buffer must be null terminated. */
@@ -371,26 +382,34 @@ read_response(SSL *tls, struct url *url)
 		goto free_response;
 	}
 
-	/* Second (or more) reads are the HTTP body response. */
-	if ((nbytes = SSL_read(tls, buf, SSL_BUF_SIZE)) < 1) {
-		warning_popup_long("SSL_read: %s: %s", "OK", NULL,
-		                   url->hostname, SSL_strerror(tls, nbytes));
-		goto free_response;
-	}
-
 	/* XDvi does all it's processing with FILE streams. */
-	if ((dvi_file = fmemopen(NULL, nbytes, "r+")) == NULL)
+	if ((dvi_file = fmemopen(NULL, response->content_len, "r+")) == NULL)
 		err(1, "fmemopen");
 
-	if (fwrite(buf, 1, nbytes, dvi_file) < nbytes)
-		err(1, "fwrite");
+	/* Second (or more) reads are the HTTP body response. */
+	while (total_bytes < response->content_len) {
+		nbytes = SSL_read(tls, buf, SSL_BUF_SIZE);
+
+		if (nbytes < 1) {
+			warning_popup_long("SSL_read: %s: %s", "OK", NULL,
+				url->hostname, SSL_strerror(tls, nbytes));
+			fclose(dvi_file);
+			dvi_file = NULL;
+			goto free_response;
+		}
+
+		if (fwrite(buf, 1, nbytes, dvi_file) < nbytes)
+			err(1, "fwrite");
+
+		total_bytes += nbytes;
+	}
 
 	if (fseek(dvi_file, 0L, SEEK_SET) < 0)
 		err(1, "fseek");
 
-	printf("Number of HTTP body bytes: %i\n", nbytes);
+	printf("Number of HTTP body bytes: %i\n", total_bytes);
 
-	if (nbytes != response->content_len)
+	if (total_bytes != response->content_len)
 		warning_popup_long("HTTP body len: expected %i but read %i\n",
 		                   "OK", NULL, response->content_len, nbytes);
 
diff --git a/http.h b/http.h
@@ -1,4 +1,4 @@
-#include <stdio.h>		/* FILE, fseek(), fwrite(), tmpfile() */
+#include <stdio.h>		/* FILE, fseek(), fwrite() */
 
 static const char addr_default[] = "www.0x30.net/resume.dvi";