torrentd

commit 691c21ea9dc4912bbe7b8c4450d2d11318464afd
parent b7d2d815cccbbfccb7bd9ad22b5a49cc1c1bcc8c
Author: sin <sin@2f30.org>
Date:   Wed, 23 Dec 2015 19:18:21 +0000

messy but prints peers

Diffstat:
M
storrent.c
 | 
3
+--
M
storrent.h
 | 
9
++++++++-
M
tracker.c
 | 
49
++++++++++++++++++++++++++++++++++++++++++++-----

3 files changed, 53 insertions(+), 8 deletions(-)
diff --git a/storrent.c b/storrent.c
@@ -15,7 +15,6 @@ usage(char *argv0)
 int
 main(int argc, char *argv[])
 {
-	struct ben *peers;
 	struct torrent *t;
 
 	if (argc != 2)
@@ -23,7 +22,7 @@ main(int argc, char *argv[])
 	if (!(t = loadtorrent(argv[1])))
 		exit(1);
 	dumptorrent(t);
-	getpeers(t, &peers);
+	getpeers(t);
 	unloadtorrent(t);
 	exit(0);
 }
diff --git a/storrent.h b/storrent.h
@@ -20,6 +20,11 @@ struct announce {
 	size_t len;
 };
 
+struct peer {
+	char hostname[256];
+	char port[6];
+};
+
 struct torrent {
 	char *buf;
 	size_t buflen;
@@ -36,6 +41,8 @@ struct torrent {
 	long long piecelen;
 	long long npieces;
 	uint32_t *piecebm;
+	struct peer *peers;
+	size_t npeers;
 };
 
 /* ben.c */
@@ -58,7 +65,7 @@ int piecehash(struct torrent *, long long, uint8_t *);
 char *peerid(void);
 
 /* tracker.c */
-int getpeers(struct torrent *, struct ben **);
+int getpeers(struct torrent *);
 
 /* util.c */
 void *emalloc(size_t);
diff --git a/tracker.c b/tracker.c
@@ -1,4 +1,10 @@
 /* See LICENSE file for copyright and license details. */
+#include <sys/socket.h>
+
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include <err.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -7,14 +13,16 @@
 #include "storrent.h"
 
 int
-getpeers(struct torrent *t, struct ben **reply)
+getpeers(struct torrent *t)
 {
+	struct sockaddr_in sa;
+	struct ben *reply, *peers;
+	struct peer *peer;
 	char *url, *proto, *host, *port, *path;
 	char *infohash, *id;
 	char buf[8192], *p;
 	int r, s;
 
-	*reply = NULL;
 	url = parseurl(t->announcers[0].urls[0], &proto, &host, &port, &path);
 	infohash = urlencode((char *)t->infohash, 20);
 	id = urlencode(peerid(), 20);
@@ -25,7 +33,7 @@ getpeers(struct torrent *t, struct ben **reply)
 
 	r = snprintf(buf, sizeof(buf),
 	             "GET /%s?info_hash=%s&peer_id=%s&port=6881&uploaded=0&"
-	             "downloaded=0&left=%zu&event=started HTTP/1.1\r\n\r\n",
+	             "downloaded=0&left=%zu&compact=1&event=started HTTP/1.1\r\n\r\n",
 	             path, infohash, id, t->totallen);
 	if (r < 0 || (size_t)r >= sizeof(buf))
 		goto fail;
@@ -47,9 +55,40 @@ getpeers(struct torrent *t, struct ben **reply)
 		p = buf;
 	}
 
-	if (!bdecode(p, p + r, reply))
+	if (!bdecode(p, p + r, &reply))
+		goto fail;
+	peers = dlookstr(reply, "peers");
+	if (!peers) {
+		warnx("no peers field in tracker reply");
+		bfree(reply);
 		goto fail;
-	bprint(*reply, 0);
+	}
+	if (peers->type != 's') {
+		warnx("expected compact reply");
+		bfree(reply);
+		goto fail;
+	}
+	if (peers->len % 6) {
+		warnx("peers length needs to be a multiple of 6 bytes");
+		bfree(reply);
+		goto fail;
+	}
+
+	for (p = peers->s; p < &peers->s[peers->len]; p += 6) {
+		t->peers = realloc(t->peers, (t->npeers + 1) * sizeof(*t->peers));
+		if (!t->peers)
+			err(1, "realloc");
+		peer = &t->peers[t->npeers];
+		memcpy(&sa.sin_addr, p, 4);
+		inet_ntop(AF_INET, &sa.sin_addr, peer->hostname,
+		          sizeof(peer->hostname));
+		snprintf(peer->port, sizeof(peer->port), "%d",
+		         (int)ntohs(*(short *)&p[4]));
+		printf("%s:%s\n", peer->hostname, peer->port);
+		t->npeers++;
+	}
+
+	bfree(reply);
 	free(id);
 	free(infohash);
 	free(url);