wdvi

network DVI viewer
Log | Files | Refs
commit 7866ab6cf117b51f328d4426d209ee79c4e2f2e9
parent 0959598e5774d02628fa74a12f7bc93d3d29960d
Author: Kyle Milz <krwmilz@gmail.com>
Date:   Thu, 19 Aug 2021 17:10:40 +0000

fetch dvi files from network

Add basic dvi fetching over HTTPS. Use openssl to make TLS connections to a
remote machine to fetch documents.

Add an address bar widget that the user can edit, and fetch documents from.

Render the fetched document in the main viewport window.

Diffstat:

MMakefile.in | 25+++++++++++++------------


Mdvi-draw.c | 40++++++++++++++++++++--------------------


Mdvi-init.c | 2++


Ahttp.c | 443+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


Ahttp.h | 5+++++


Mxdvi.c | 103++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------


Mxdvi.h | 2+-


7 files changed, 547 insertions(+), 73 deletions(-)

diff --git a/Makefile.in b/Makefile.in
@@ -33,13 +33,13 @@ EXTRA_CPPFLAGS=@EXTRA_CPPFLAGS@
 LDFLAGS=@LDFLAGS@
 X_LDFLAGS=@LDFLAGS@ @x_linker_options@ @X_LIBS@
 X_LIBS=@X_PRE_LIBS@ -lX11 @X_EXTRA_LIBS@
-EXTRA_LIBS=@EXTRA_LIBS@
+EXTRA_LIBS=@EXTRA_LIBS@ -lcrypto -lssl
 LIBS=@LIBS@ @MATH_LIB@
 
 SRCS=xdvi.c events.c dvi-init.c dvi-draw.c special.c font-open.c filefind.c \
-  pk.c vf.c util.c@OPT_SRCS@
+  pk.c vf.c util.c http.c@OPT_SRCS@
 OBJS=xdvi.o events.o dvi-init.o dvi-draw.o special.o font-open.o filefind.o \
-  pk.o vf.o util.o@OPT_OBJS@
+  pk.o vf.o util.o http.o@OPT_OBJS@
 
 INSTALL=@INSTALL@
 INSTALL_PROGRAM=@INSTALL_PROGRAM@
@@ -48,8 +48,8 @@ INSTALL_DATA=@INSTALL_DATA@
 all: xdvi$(EXEEXT) xdvi.man
 
 xdvi$(EXEEXT):	$(OBJS)
-	$(CC) $(X_LDFLAGS) -o xdvi $(OBJS) $(X_LIBS) $(EXTRA_LIBS) $(LIBS)
-	$(CHMOD) go+rx xdvi$(EXEEXT)
+	$(CC) $(X_LDFLAGS) -o wdvi $(OBJS) $(X_LIBS) $(EXTRA_LIBS) $(LIBS)
+	$(CHMOD) go+rx wdvi$(EXEEXT)
 
 .c.o:
 	$(CC) -c $(CFLAGS) $(X_CFLAGS) $(EXTRA_CPPFLAGS) $<
@@ -70,6 +70,7 @@ psgs.o:		config.h xdvi.h
 font-open.o:	config.h xdvi.h filf-app.h filefind.h
 special.o:	config.h xdvi.h filf-app.h filefind.h
 filefind.o:	config.h xdvi.h filf-app.h filefind.h
+http.o:		config.h xdvi.h
 
 krheader.h:	xdvi.c config.h xdvi.h Makefile
 	$(CPP) -DMAKING_HEADER $(srcdir)/xdvi.c \
@@ -92,9 +93,9 @@ xdvi.man: xdvi-man.sed mksedscript Makefile config.h
 
 check:
 
-install-bin: xdvi$(EXEEXT)
-	strip xdvi$(EXEEXT)
-	$(INSTALL_PROGRAM) xdvi$(EXEEXT) ${bindir}/xdvi$(EXEEXT)
+install-bin: wdvi$(EXEEXT)
+	strip wdvi$(EXEEXT)
+	$(INSTALL_PROGRAM) wdvi$(EXEEXT) ${bindir}/wdvi$(EXEEXT)
 	$(INSTALL_PROGRAM) $(srcdir)/xdvizilla ${bindir}/xdvizilla
 
 install-man: xdvi.man
@@ -111,7 +112,7 @@ install-data: config.xdvi
 install: install-bin install-man install-data
 
 uninstall:
-	-$(RM) ${bindir}/xdvi$(EXEEXT) ${mandir}/man$(MANEXT)/xdvi.$(MANEXT)
+	-$(RM) ${bindir}/wdvi$(EXEEXT) ${mandir}/man$(MANEXT)/xdvi.$(MANEXT)
 	-$(RM) ${bindir}/xdvizilla ${mandir}/man$(MANEXT)/xdvizilla.$(MANEXT)
 	@if grep "original config.xdvi --" "$(datadir)$(dvipsconfdir)/config.xdvi" >/dev/null 2>&1 \
 	    || test ! -r "$(datadir)$(dvipsconfdir)/config.xdvi"; then \
@@ -123,14 +124,14 @@ TAGS:	$(srcs)
 	etags $(srcs)
 
 mostlyclean:
-	-$(RM) *.o xdvi$(EXEEXT) xdvi.man core sedscript *~
+	-$(RM) *.o wdvi$(EXEEXT) xdvi.man core sedscript *~
 
 archclean:
-	-$(RM) *.o xdvi$(EXEEXT) Makefile
+	-$(RM) *.o wdvi$(EXEEXT) Makefile
 	-$(RM) config.h config.cache config.status config.log
 
 clean:
-	-$(RM) *.o xdvi$(EXEEXT) xdvi.man core sedscript krheader.h *~
+	-$(RM) *.o wdvi$(EXEEXT) xdvi.man core sedscript krheader.h *~
 	-$(RM) psheader.c squeeze$(EXEEXT)
 
 distclean: clean
diff --git a/dvi-draw.c b/dvi-draw.c
@@ -223,7 +223,7 @@ put_image(g, x, y)
  *	Byte reading routines for dvi file.
  */
 
-#define	xtell(pos)	(lseek(fileno(dvi_file), 0L, SEEK_CUR) - \
+#define	xtell(pos)	(fseek(dvi_file, 0L, SEEK_CUR) - \
 			    (currinf.end - (pos)))
 
 static	ubyte
@@ -234,8 +234,8 @@ xxone()
 	    return EOP;
 	}
 	currinf.end = dvi_buffer +
-	    read(fileno(dvi_file), (char *) (currinf.pos = dvi_buffer),
-		DVI_BUFFER_LEN);
+		fread((char *) (currinf.pos = dvi_buffer), 1, DVI_BUFFER_LEN,
+			dvi_file);
 	return currinf.end > dvi_buffer ? *(currinf.pos)++ : EOF;
 }
 
@@ -275,7 +275,7 @@ xskip(offset)
 {
 	currinf.pos += offset;
 	if (!currinf.virtual && currinf.pos > currinf.end)
-	    (void) lseek(fileno(dvi_file), (long) (currinf.pos - currinf.end),
+	    (void) fseek(dvi_file, (long) (currinf.pos - currinf.end),
 		SEEK_CUR);
 }
 
@@ -293,7 +293,7 @@ tell_oops(const char *message, ...)
 	if (currinf.virtual)
 	    Fprintf(stderr, " in virtual font %s\n", currinf.virtual->fontname);
 	else
-	    Fprintf(stderr, ", offset %jd\n", xtell(currinf.pos - 1));
+	    Fprintf(stderr, ", offset %ld\n", xtell(currinf.pos - 1));
 	xdvi_exit(1);
 }
 
@@ -824,7 +824,7 @@ prescan()
 	dvi_file_ready = False;
 
 	nextreportpage = scanned_page;
-	(void) lseek(fileno(dvi_file), page_info[scanned_page + 1].offset,
+	(void) fseek(dvi_file, page_info[scanned_page + 1].offset,
 	  SEEK_SET);
 	currinf.pos = currinf.end = dvi_buffer;
 
@@ -1368,7 +1368,7 @@ draw_part(minframe, current_dimconv)
 					oldinfo.end = currinf.end;
 				    }
 				    else {
-					(void) lseek(fileno(dvi_file), file_pos,
+					(void) fseek(dvi_file, file_pos,
 					    SEEK_SET);
 					oldinfo.pos = oldinfo.end;
 				    }
@@ -1513,7 +1513,7 @@ draw_page()
 	  ROUNDUP(page_info[current_page].pw, shrink_factor) + 1,
 	  ROUNDUP(page_info[current_page].ph, shrink_factor) + 1);
 
-	(void) lseek(fileno(dvi_file), page_info[current_page].offset,
+	(void) fseek(dvi_file, page_info[current_page].offset,
 	  SEEK_SET);
 
 	bzero((char *) &currinf.data, sizeof currinf.data);
@@ -1884,7 +1884,7 @@ geom_scan_part(g_info, minframe, current_dimconv)
 					oldinfo.end = currinf.end;
 				    }
 				    else {
-					(void) lseek(fileno(dvi_file), file_pos,
+					(void) fseek(dvi_file, file_pos,
 					    SEEK_SET);
 					oldinfo.pos = oldinfo.end;
 				    }
@@ -2027,9 +2027,9 @@ geom_scan(g_info)
 #endif
 
 	if (dvi_pointer_frame != NULL)
-	    pos_save = lseek(fileno(dvi_file), 0L, SEEK_CUR)
+	    pos_save = fseek(dvi_file, 0L, SEEK_CUR)
 	      - (dvi_pointer_frame->end - dvi_pointer_frame->pos);
-	(void) lseek(fileno(dvi_file), page_info[current_page].offset,
+	(void) fseek(dvi_file, page_info[current_page].offset,
 	  SEEK_SET);
 
 	currinf_save = currinf;
@@ -2049,7 +2049,7 @@ geom_scan(g_info)
 	currinf = currinf_save;
 
 	if (dvi_pointer_frame != NULL) {
-	    (void) lseek(fileno(dvi_file), pos_save, SEEK_SET);
+	    (void) fseek(dvi_file, pos_save, SEEK_SET);
 	    dvi_pointer_frame->pos = dvi_pointer_frame->end = dvi_buffer;
 	}
 }
@@ -2527,7 +2527,7 @@ source_reverse_search(x, y)
 	    /* Save file position */
 
 	    if (dvi_pointer_frame != NULL)
-		pos_save = lseek(fileno(dvi_file), 0L, SEEK_CUR)
+		pos_save = fseek(dvi_file, 0L, SEEK_CUR)
 		  - (dvi_pointer_frame->end - dvi_pointer_frame->pos);
 
 	    currinf_save = currinf;
@@ -2538,7 +2538,7 @@ source_reverse_search(x, y)
 	    for (;;) {
 
 		if (++upper < total_pages) {
-		    (void) lseek(fileno(dvi_file), page_info[upper].offset,
+		    (void) fseek(dvi_file, page_info[upper].offset,
 		      SEEK_SET);
 		    bzero((char *) &currinf.data, sizeof currinf.data);
 		    currinf.tn_table_len = TNTABLELEN;
@@ -2560,7 +2560,7 @@ source_reverse_search(x, y)
 		    break;
 
 		if (--lower >= 0) {
-		    (void) lseek(fileno(dvi_file), page_info[lower].offset,
+		    (void) fseek(dvi_file, page_info[lower].offset,
 		      SEEK_SET);
 		    bzero((char *) &currinf.data, sizeof currinf.data);
 		    currinf.tn_table_len = TNTABLELEN;
@@ -2591,7 +2591,7 @@ source_reverse_search(x, y)
 	    currinf = currinf_save;
 
 	    if (dvi_pointer_frame != NULL) {
-		(void) lseek(fileno(dvi_file), pos_save, SEEK_SET);
+		(void) fseek(dvi_file, pos_save, SEEK_SET);
 		dvi_pointer_frame->pos = dvi_pointer_frame->end = dvi_buffer;
 	    }
 
@@ -2886,9 +2886,9 @@ source_forward_search(str)
 	   drawing).  */
 
 	if (dvi_pointer_frame != NULL)
-	    pos_save = lseek(fileno(dvi_file), 0L, SEEK_CUR)
+	    pos_save = fseek(dvi_file, 0L, SEEK_CUR)
 	      - (dvi_pointer_frame->end - dvi_pointer_frame->pos);
-	(void) lseek(fileno(dvi_file), page_info[0].offset, SEEK_SET);
+	(void) fseek(dvi_file, page_info[0].offset, SEEK_SET);
 
 	currinf_save = currinf;
 	maxchar_save = maxchar;
@@ -2925,7 +2925,7 @@ source_forward_search(str)
 		currinf = currinf_save;
 
 		if (dvi_pointer_frame != NULL) {
-		    (void) lseek(fileno(dvi_file), pos_save, SEEK_SET);
+		    (void) fseek(dvi_file, pos_save, SEEK_SET);
 		    dvi_pointer_frame->pos = dvi_pointer_frame->end
 		      = dvi_buffer;
 		}
@@ -2967,7 +2967,7 @@ source_forward_search(str)
 	  -0x7fffffff;
 	source_fwd_box_page = -1;	/* in case of error, suppress box */
 
-	(void) lseek(fileno(dvi_file), page_info[best_page].offset, SEEK_SET);
+	(void) fseek(dvi_file, page_info[best_page].offset, SEEK_SET);
 	currinf.tn_table_len = TNTABLELEN;
 	currinf.tn_table = tn_table;
 	currinf.tn_head = tn_head;
diff --git a/dvi-init.c b/dvi-init.c
@@ -922,6 +922,8 @@ check_dvi_file()
 	if (!dvi_is_valid)
 	    return False;
 
+	return True;
+
 	if (dvi_file == NULL) {
 	    /* check if file exists and has changed */
 	    if (!(ev_flags & EV_NEWDOC) && stat(dvi_name, &buf) == 0
diff --git a/http.c b/http.c
@@ -0,0 +1,443 @@
+/*
+ * Copyright (c) 2020 Kyle Milz <krwmilz@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/socket.h>		/* connect(), socket() */
+
+#include <arpa/inet.h>		/* inet_ntoa() */
+#include <netdb.h>		/* gethostbyname() */
+#include <netinet/in.h>		/* struct sockaddr_in */
+
+#include <assert.h>
+#include <err.h>		/* err() */
+#include <stdio.h>		/* sscanf, fmemopen */
+#include <stdlib.h>		/* strtonum() */
+#include <unistd.h>		/* close() */
+
+#include <openssl/err.h>	/* ERR_load_crypto_strings() */
+#include <openssl/evp.h>	/* OpenSSL_add_all_algorithms() */
+#include <openssl/ssl.h>
+
+#include "xdvi.h"		/* warning_popup_long() */
+#include "util.h"		/* xmalloc() */
+
+
+#define SSL_BUF_SIZE		16 * 1024
+
+
+struct url {
+	const char	*orig_url;
+	char 	 	 hostname[128];
+	int	 	 port;
+	char 	 	 document[128];
+};
+
+struct http_headers {
+	char		proto[9];		/* HTTP/1.1 or whatever */
+	int		status;			/* 200, 404, etc */
+	char		status_text[32];	/* 416 may be the longest? */
+	int		content_len;		/* Content-Length: */
+};
+
+
+/*
+ * Try and parse dest_url[] as a url:
+ * - ignore protocol if found
+ * - hostname is either what's remaining or up to a colon or slash character
+ * - if colon is found, port number is either what is remaining or up to slash
+ *   character
+ * - if slash is found the rest of the string is a document path
+ *
+ * On successful parse a filled in struct url is returned that the caller must
+ * free, otherwise a NULL pointer is returned.
+ */
+static struct url *
+parse_url(const char dest_url[])
+{
+	struct url	*url;
+	const char	*hostname_end;
+	const char	*proto_loc;
+	const char	*colon_loc;
+	const char	*slash_loc;
+	char	 	 portnum[6];
+	const char	*errstr;
+
+	url = xmalloc(sizeof(struct url));
+	url->port = 443;
+	url->orig_url = dest_url;
+
+	hostname_end = dest_url + strlen(dest_url);
+
+	/* Skip protocol if found. */
+	if ((proto_loc = strstr(dest_url, "://")))
+		dest_url = proto_loc + strlen("://");
+
+	colon_loc = strchr(dest_url, ':');
+	slash_loc = strchr(dest_url, '/');
+
+	/* Try and parse port number if found. */
+	if (colon_loc) {
+		hostname_end = colon_loc;
+
+		if (slash_loc)
+			strlcpy(portnum, colon_loc + 1, slash_loc - colon_loc);
+		else
+			strlcpy(portnum, colon_loc + 1, sizeof(portnum));
+
+		/* Port numbers cannot be larger than 65535. */
+		url->port = strtonum(portnum, 1, 64 * 1024 - 1, &errstr);
+		if (errstr != NULL) {
+			warning_popup_long("%s: port number '%s': %s",
+			                   "OK", NULL,
+			                   dest_url, portnum, errstr);
+			return NULL;
+		}
+	}
+
+	/* Set document path if found. */
+	if (slash_loc) {
+		strlcpy(url->document, slash_loc, sizeof(url->document));
+
+		if (colon_loc == NULL)
+			hostname_end = slash_loc;
+	} else
+		strcpy(url->document, "/");
+
+	strlcpy(url->hostname, dest_url, hostname_end - dest_url + 1);
+
+	return url;
+}
+
+
+/*
+ * Takes a struct url and resolves the url hostname. Then tries connecting to
+ * the url hostname using the url port.
+ *
+ * On success return an open socket represented by a non negative integer or
+ * -1 on failure.
+ */
+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);
+
+	memset(&(dest_addr.sin_zero), '\0', 8);
+
+	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;
+	}
+
+	return sockfd;
+}
+
+
+/*
+ * Map some SSL error codes to real messages. This should exist somewhere
+ * already?
+ *
+ * Returns a message and never fails.
+ */
+static const char *
+SSL_strerror(const SSL *tls, int ret)
+{
+	switch (SSL_get_error(tls, ret)) {
+	case SSL_ERROR_NONE:
+		return "No error";
+	case SSL_ERROR_ZERO_RETURN:
+		return "TLS connection has been closed";
+	case SSL_ERROR_WANT_READ:
+	case SSL_ERROR_WANT_WRITE:
+	case SSL_ERROR_WANT_CONNECT:
+	case SSL_ERROR_WANT_ACCEPT:
+	case SSL_ERROR_WANT_X509_LOOKUP:
+		return "TLS operation did not complete";
+	case SSL_ERROR_SYSCALL:
+		return "I/O error occurred";
+	case SSL_ERROR_SSL:
+		return "Failure in SSL library";
+	}
+
+	return "Unknown TLS error";
+}
+
+
+/*
+ * Connect to the host using TLS.
+ *
+ * Returns an SSL pointer on success or NULL on failure.
+ */
+static SSL *
+tls_connect(int server, struct url *url)
+{
+	const SSL_METHOD	*method;
+	SSL_CTX			*ctx;
+	SSL			*tls;
+	X509			*cert = NULL;
+	X509_NAME		*certname = NULL;
+	BIO			*outbio;
+	int			 ret, j, fprint_size;
+	const EVP_MD		*fprint_type;
+	unsigned char		 fprint[EVP_MAX_MD_SIZE];
+	EVP_PKEY		*pkey = NULL;
+
+
+	/* According to LibreSSL manual pages none of these are necessary. */
+	OpenSSL_add_all_algorithms();
+	ERR_load_BIO_strings();
+	ERR_load_crypto_strings();
+	SSL_load_error_strings();
+
+	/* Not needed for newer (> 1.1.0) library versions? */
+	assert(SSL_library_init() == 1);
+
+	method = TLS_client_method();
+
+	if ((ctx = SSL_CTX_new(method)) == NULL)
+		errx(1, "Unable to create new SSL context structure.\n");
+
+	if ((tls = SSL_new(ctx)) == NULL)
+		errx(1, "Unable to create new SSL structure.\n");
+
+	SSL_set_fd(tls, server);
+
+	if ((ret = SSL_connect(tls)) != 1) {
+		warning_popup_long("%s:%i: Cannot make TLS connection",
+		                   "OK", NULL, url->hostname, url->port);
+
+		/* Print SSL_strerror(tls, ret)); too? */
+		return NULL;
+	}
+
+	if ((cert = SSL_get_peer_certificate(tls)) == NULL) {
+		warning_popup_long("%s:%i: No TLS certificate was presented by peer",
+		                   "OK", NULL, url->hostname, url->port);
+		return NULL;
+	}
+
+	certname = X509_NAME_new();
+	certname = X509_get_subject_name(cert);
+
+	outbio = BIO_new_fp(stdout, BIO_NOCLOSE);
+	BIO_printf(outbio, "Certificate subject data: ");
+	X509_NAME_print_ex(outbio, certname, 0, 0);
+	BIO_printf(outbio, "\n");
+
+	/* Calculate certificate fingerprint. */
+	fprint_type = EVP_sha256();
+
+	if (!X509_digest(cert, fprint_type, fprint, &fprint_size)) {
+		warning_popup_long("%s:%i: Cannot create TLS certificate fingerprint",
+		              "OK", NULL, url->hostname, url->port);
+		return NULL;
+	}
+
+	BIO_printf(outbio, "Fingerprint (method = %s, size = %d): ",
+		OBJ_nid2sn(EVP_MD_type(fprint_type)), fprint_size);
+
+	for (j = 0; j < fprint_size; j++) {
+		BIO_printf(outbio, "%02X%c", fprint[j],
+			(j + 1 == fprint_size) ? '\n' : ':');
+	}
+	BIO_printf(outbio, "\n");
+
+	/* Get certificate public key. */
+	if ((pkey = X509_get_pubkey(cert)) == NULL) {
+		warning_popup_long("%s:%i: No public key in certificate.",
+		              "OK", NULL, url->hostname, url->port);
+		return NULL;
+	}
+	PEM_write_bio_PUBKEY(outbio, pkey);
+
+	X509_free(cert);
+	BIO_free_all(outbio);
+
+	return tls;
+}
+
+
+static int
+send_request(SSL *tls, struct url *url)
+{
+	const char	*req_fmt;
+	char		*req;
+	int	 	 ret;
+
+	req_fmt = "GET %s HTTP/1.1\r\n"
+	          "Host: %s\r\n"
+	          "\r\n";
+
+	if (asprintf(&req, req_fmt, url->document, url->hostname) == -1)
+		err(1, "asprintf");
+
+	if ((ret = SSL_write(tls, req, strlen(req))) < 1) {
+		warning_popup_long("%s: %s", "OK", NULL, url->hostname,
+		                   SSL_strerror(tls, ret));
+		free(req);
+		return 1;
+	}
+
+	free(req);
+	return 0;
+}
+
+
+/*
+ * Parse a buffer that supposedly contains HTTP headers.
+ *
+ * Return a pointer to an allocated struct http_headers that the caller must
+ * free.
+ */
+static struct http_headers *
+parse_headers(char *buf, int bytes_read)
+{
+	char			 header[32], value[32]; /* unbounded len? */
+	struct http_headers	*res;
+	int			 pos;
+
+	if ((res = calloc(1, sizeof(struct http_headers))) == NULL)
+		err(1, NULL);
+
+	/* First line of response is 'HTTP/1.1 200 OK' for example. */
+	sscanf(buf, "%8s %i %31[^\r\n]%n", res->proto, &res->status,
+		res->status_text, &pos);
+	buf += pos;
+
+	while (sscanf(buf, "%31s %31[^\r\n]%n", header, value, &pos) != EOF) {
+		if (strcmp(header, "Content-Length:") == 0)
+			res->content_len = atoi(value);
+		
+		buf += pos;
+	}
+
+	return res;
+}
+
+
+static FILE *
+read_response(SSL *tls, struct url *url)
+{
+	char			*buf;
+	struct http_headers	*response;
+	int			 nbytes;
+	FILE			*dvi_file = NULL;
+
+	/* This buffer must be null terminated. */
+	buf = calloc(1, SSL_BUF_SIZE);
+
+	/* First read yields the HTTP header response in its entirety. */
+	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_buf;
+	}
+
+	/* We must free returned response. */
+	response = parse_headers(buf, nbytes);
+
+	if (response->status != 200) {
+		warning_popup_long("%s: %i %s", "OK", NULL, url->orig_url,
+		                   response->status, response->status_text);
+		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)
+		err(1, "fmemopen");
+
+	if (fwrite(buf, 1, nbytes, dvi_file) < nbytes)
+		err(1, "fwrite");
+
+	if (fseek(dvi_file, 0L, SEEK_SET) < 0)
+		err(1, "fseek");
+
+	printf("Number of HTTP body bytes: %i\n", nbytes);
+
+	if (nbytes != response->content_len)
+		warning_popup_long("HTTP body len: expected %i but read %i\n",
+		                   "OK", NULL, response->content_len, nbytes);
+
+free_response:
+	free(response);
+free_buf:
+	free(buf);
+
+	return dvi_file;
+}
+
+/*
+ * Gets the dest_url[] using a tls connection to the host, then writes the
+ * returned dvi document into a temporary file, which it returns.
+ *
+ * Returns a FILE * pointer on success or NULL pointer on failure.
+ */
+FILE *
+http_get(const char dest_url[])
+{
+	struct url	*url;
+	int		 server;
+	SSL		*tls;
+	FILE		*dvi_file = NULL;
+
+	if ((url = parse_url(dest_url)) == NULL)
+		return NULL;
+
+	if ((server = xconnect(url)) < 0)
+		goto free_url;
+
+	if ((tls = tls_connect(server, url)) == NULL)
+		goto free_server;
+
+	if (send_request(tls, url))
+		goto free_tls;
+
+	if ((dvi_file = read_response(tls, url)) == NULL)
+		goto free_tls;
+
+free_tls:
+	SSL_CTX_free(SSL_get_SSL_CTX(tls));
+	SSL_free(tls);
+free_server:
+	close(server);
+free_url:
+	free(url);
+
+	return dvi_file;
+}
diff --git a/http.h b/http.h
@@ -0,0 +1,5 @@
+#include <stdio.h>		/* FILE, fseek(), fwrite(), tmpfile() */
+
+static const char addr_default[] = "www.0x30.net/resume.dvi";
+
+FILE *http_get(const char[]);
diff --git a/xdvi.c b/xdvi.c
@@ -73,6 +73,7 @@ NOTE:
  */
 
 #include "xdvi.h"
+#include "http.h"
 
 #if !lint
 static	char	copyright[] UNUSED =
@@ -127,17 +128,9 @@ static	char	copyright[] UNUSED =
 
 #include <X11/Shell.h>	/* needed for def. of XtNiconX */
 
-
-#  include <X11/Xaw/Viewport.h>
-#define	VPORT_WIDGET_CLASS	viewportWidgetClass
-#define	DRAW_WIDGET_CLASS	drawWidgetClass
-
-#ifdef	BUTTONS
-#  include <X11/Xaw/Command.h>
-#define	FORM_WIDGET_CLASS	formWidgetClass
-#endif /* BUTTONS */
-
-
+#include <X11/Xaw/Viewport.h>
+#include <X11/Xaw/AsciiText.h>
+#include <X11/Xaw/Command.h>
 
 # if HAVE_X11_INTRINSICI_H
 #  include <X11/IntrinsicI.h>
@@ -778,13 +771,11 @@ static	WidgetClassRec	drawingWidgetClass = {
 #endif /* NOQUERY */
 
 static	Arg	vport_args[] = {
-#ifdef	BUTTONS
 	{XtNborderWidth,	(XtArgVal) 0},
 	{XtNtop,		(XtArgVal) XtChainTop},
 	{XtNbottom,		(XtArgVal) XtChainBottom},
 	{XtNleft,		(XtArgVal) XtChainLeft},
 	{XtNright,		(XtArgVal) XtChainRight},
-#endif
 	{XtNallowHoriz,		(XtArgVal) True},
 	{XtNallowVert,		(XtArgVal) True},
 };
@@ -797,12 +788,17 @@ static	Arg	draw_args[] = {
 	{XtNlabel,		(XtArgVal) ""},
 };
 
-#if BUTTONS
+static	Arg	addr_args[] = {
+	{XtNwidth,		(XtArgVal) 0},
+	{XtNfromVert,		(XtArgVal) NULL},
+	{XtNdataCompression,	(XtArgVal) False},
+	{XtNeditType,		(XtArgVal) XawtextEdit},
+	{XtNstring,		(XtArgVal) addr_default},
+};
+
 static	Arg	form_args[] = {
 	{XtNdefaultDistance,	(XtArgVal) 0},
 };
-#endif
-
 
 static	void	usage(const char *, ...) NORETURN;
 
@@ -1611,6 +1607,35 @@ compile_wheel_actions()
 	*wactpp = NULL;
 }
 
+static void
+cb_addr_go(Widget w, XtPointer client_data, XtPointer call_data)
+{
+	const char *s;
+
+	if (w == NULL)
+		s = addr_default;
+	else
+		XtVaGetValues(addr_widget, XtNstring, &s, NULL);
+
+	printf(">>> cb_addr_go: '%s'\n", s);
+
+	dvi_file = http_get(s);
+	if (dvi_file == NULL)
+		return;
+
+	ev_flags |= EV_NEWDOC;
+}
+
+static void
+act_addr_go P4C(Widget, w, XEvent *, event, String *, params,
+	Cardinal *, num_params)
+{
+	cb_addr_go(w, NULL, NULL);
+}
+
+static XtActionsRec	addr_actions[] = {
+	{"addr-go",	act_addr_go}
+};
 
 
 /*
@@ -1844,7 +1869,9 @@ or invalid argument:\n\t\"%s\", \"%s\".",
 
 	if (dvi_name == NULL) {
 	    postpone_popups = False;
-	    Act_open_dvi_file(NULL, NULL, NULL, 0);
+		act_addr_go(NULL, NULL, NULL, 0);
+		dvi_name = "resume.dvi";
+	    // Act_open_dvi_file(NULL, NULL, NULL, 0);
 	    (void) read_events(EV_GE_NEWDOC);
 	    ev_flags &= ~EV_NEWDOC;
 	    postpone_popups = True;
@@ -2097,21 +2124,11 @@ argument is to override any papersize specials in the dvi file.\n\n", stderr);
 
 	    db = XtScreenDatabase(SCRN);
 
-	    XrmPutStringResource(&db,
-#  if BUTTONS
-	      "XDvi.form.baseTranslations",
-#  else
-	      "XDvi.vport.baseTranslations",
-#  endif
+	    XrmPutStringResource(&db, "XDvi.form.baseTranslations",
 	      base_translations);
 
 	    if (resource.main_translations != NULL)
-		XrmPutStringResource(&db,
-#  if BUTTONS
-		  "XDvi.form.translations",
-#  else
-		  "XDvi.vport.translations",
-#  endif
+		XrmPutStringResource(&db, "XDvi.form.translations",
 		  resource.main_translations);
 
 
@@ -2119,21 +2136,13 @@ argument is to override any papersize specials in the dvi file.\n\n", stderr);
 	     * not change db (X11R6.4 source).  */
 	}
 
-#if BUTTONS
 
-	form_widget = XtCreateManagedWidget("form", FORM_WIDGET_CLASS,
+	form_widget = XtCreateManagedWidget("form", formWidgetClass,
 	  top_level, form_args, XtNumber(form_args));
 #define	form_or_top	form_widget	/* for calls later on */
 #define	form_or_vport	form_widget
 
-#else /* not BUTTONS */
-
-#define	form_or_top	top_level	/* for calls later on */
-#define	form_or_vport	vport_widget
-
-#endif /* not BUTTONS */
-
-	vport_widget = XtCreateManagedWidget("vport", VPORT_WIDGET_CLASS,
+	vport_widget = XtCreateManagedWidget("vport", viewportWidgetClass,
 	  form_or_top, vport_args, XtNumber(vport_args));
 
 
@@ -2142,10 +2151,24 @@ argument is to override any papersize specials in the dvi file.\n\n", stderr);
 
 	draw_args[0].value = (XtArgVal) page_w;
 	draw_args[1].value = (XtArgVal) page_h;
-	draw_widget = XtCreateManagedWidget("drawing", DRAW_WIDGET_CLASS,
+	draw_widget = XtCreateManagedWidget("drawing", drawWidgetClass,
 	  vport_widget, draw_args, XtNumber(draw_args));
 
 
+	XtAddActions(addr_actions, XtNumber(addr_actions));
+
+	addr_args[0].value = (XtArgVal) page_w;
+	addr_args[1].value = (XtArgVal) vport_widget;
+	addr_widget = XtCreateManagedWidget("address", asciiTextWidgetClass,
+		form_or_top, addr_args, XtNumber(addr_args));
+
+	XawTextSetInsertionPoint(addr_widget, strlen(addr_default));
+	XtTranslations xlats =
+		XtParseTranslationTable("<Key>Return:addr-go()");
+	XtOverrideTranslations(addr_widget, xlats);
+
+
+
 
 	XtOverrideTranslations(
 				form_or_vport,
diff --git a/xdvi.h b/xdvi.h
@@ -766,8 +766,8 @@ Boolean		drawing_mag	= False;
 
 Widget		top_level	= 0;
 Widget		vport_widget, draw_widget, clip_widget;
+Widget		addr_widget, form_widget;
 # if BUTTONS
-Widget		form_widget;
 int		xtra_wid	= 0;
 extern	const char	default_button_config[]; /* defined in events.c */
 Widget		panel_widget;