From bac15e7edf532c4a87f0f219c8f70d93d4c7e752 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anton=20Luka=20=C5=A0ijanec?= <anton@sijanec.eu>
Date: Tue, 18 Jan 2022 14:05:06 +0100
Subject: dela

---
 main.c | 51 ++++++++++++++++++++++++++++++---------------------
 1 file changed, 30 insertions(+), 21 deletions(-)

(limited to 'main.c')

diff --git a/main.c b/main.c
index 41b18dc..c96bc8e 100644
--- a/main.c
+++ b/main.c
@@ -28,10 +28,11 @@
 #define XSTR(x) #x
 #define STR(x) XSTR(x)
 #define HELP "find recursive DNS resolvers on IPv4 networks\n" \
-	"%s [-a ip] [-b ip] [-d domain] [-h] [-o file] [-p port] [-t μs] [-w μs] net1 [net2 ...]\n" \
+	"%s [-a ip] [-b ip] [-d domain] [-eh] [-o file] [-p port] [-t μs] [-w μs] net1 [net2 ...]\n" \
 	"	-a Specify the IPv4 of the -d domain to be used instead of getaddrinfo(3).\n" \
 	"	-b Bind on a specific interface, defined by IPv4. Default is any interface.\n" \
 	"	-d Specify the domain name to be used in queries that has a single A record.\n" \
+	"	-e Exclude sent packets from -o PCAP output (they're all the same).\n" \
 	"	-h Show this help and exit.\n" \
 	"	-o Output PCAP to filename. Any existing file is truncated. No IP/UDP checksums.\n" \
 	"	-p Set the source port number to use instead of a dynamically asigned one.\n" \
@@ -234,8 +235,6 @@ struct question {
 	uint16_t class			__attribute__((packed));
 } __attribute__((packed));
 int logudp (int o /* fd */, struct sockaddr_in s, struct sockaddr_in d, char * u, size_t l /* d */) {
-	if (o == -1)
-		return -1;
 	struct timespec t;
 	if (clock_gettime(CLOCK_REALTIME, &t) == -1) {
 		perror("clock_gettime(CLOCK_REALTIME, &t)");
@@ -361,11 +360,12 @@ int main (int argc, char ** argv) {
 	int j = -1; /* host in network index */
 	int t = 1000;
 	int w = 1000000;
-	struct in_addr h; /* host to scan */
+	int e = 0; /* whether to exclude sent packets in PCAP - they're all the same */
+	struct in_net h; /* host to scan is .addr, h as struct in_net is returned from host() */
 	signal(SIGINT, handler);
 	signal(SIGTERM, handler);
 	while (1) {
-		switch (getopt(argc, argv, ":a:b:d:ho:p:t:w:")) {
+		switch (getopt(argc, argv, ":a:b:d:eho:p:t:w:")) {
 			case 'a':
 				inet_aton(optarg, &a);
 				break;
@@ -375,6 +375,9 @@ int main (int argc, char ** argv) {
 			case 'd':
 				d = optarg;
 				break;
+			case 'e':
+				e++;
+				break;
 			case 'h':
 				printf(HELP, argv[0]);
 				r = 0;
@@ -459,7 +462,7 @@ o:
 		.tv_sec = 0
 	};
 	while (!finish) {
-		if (!(h = host(n[i], ++j)).s_addr) {
+		if ((h = host(n[i], ++j)).mask.s_addr != INADDR_BROADCAST) {
 			if (++i >= l) {
 				fprintf(stderr, "finished sending, waiting for last replies\n");
 				if (clock_gettime(CLOCK_MONOTONIC, &lp) == -1) {
@@ -472,12 +475,12 @@ o:
 			else
 				h = host(n[i], (j = 0));
 		}
-		struct sockaddr_in e = {
-			.sin_family = AF_INET,
-			.sin_port = htons(53),
-			.sin_addr = h
-		};
-		struct header h = {
+		struct sockaddr_in m = {	/* see, I don't know much about scopes in C and I'm */
+			.sin_family = AF_INET,	/* intentionally excercising them for the cost of */
+			.sin_port = htons(53),	/* code unreadability. in this scope I defined h */
+			.sin_addr = h.addr	/* as struct header, in parent scope it was in_net, */
+		};				/* and I used h as in_net in this scope as well, */
+		struct header h = {		/* but h as header is declared after that use (; */
 			.xid = 0x6969, /* oh no, cache poisoning, whatever'll I do */
 			.flags = htons(QUESTION | QUERY | RD),
 			.qdcount = htons(1),
@@ -504,13 +507,13 @@ o:
 		c = (char *) memcpy(c, &y, 2) + 2;
 		c = (char *) memcpy(c, &k, 2) + 2;
 		int ž;
-		if ((ž = logudp(o, b, e, u, L)) < -1) {
-			fprintf(stderr, "logudp(o, b, e, u, L) == %d\n", ž);
+		if (!e && o != -1 && (ž = logudp(o, b, m, u, L)) < -1) {
+			fprintf(stderr, "logudp(o, b, m, u, L) == %d\n", ž);
 			r = 13;
 			goto r;
 		}
-		if (sendto(s, u, L, 0, (struct sockaddr *) &e, sizeof(struct sockaddr)) == -1) {
-			perror("sendto(s, u, L, 0, (struct sockaddr *) &e, sizeof(struct sockaddr))");
+		if (sendto(s, u, L, 0, (struct sockaddr *) &m, sizeof(struct sockaddr)) == -1) {
+			perror("sendto(s, u, L, 0, (struct sockaddr *) &m, sizeof(struct sockaddr))");
 			r = 14;
 			goto r;
 		}
@@ -562,17 +565,23 @@ i:
 			}
 			if (lp.tv_sec)
 				lp = z; /* this loop ends nearly in an instant */
-			if ((ž = logudp(o, f, b, u, š)) < -1) {
+			if (o != -1 && (ž = logudp(o, f, b, u, š)) < -1) {
 				fprintf(stderr, "logudp(o, f, b, u, š) == %d\n", ž);
 				return 3;
 			}
-			fprintf(stderr, "received response from %s\n", inet_ntoa(f.sin_addr));
+			fprintf(stderr, "RESPONSE\t%s", inet_ntoa(f.sin_addr));
 			ž = 0;
 			struct in_addr i = parse_a(u, 65535, d, strlen(d), ž++);
-			if (i.s_addr == a.s_addr) /* if we go back to multithread, change to write. */
-				printf("WORKING %s\n", inet_ntoa(f.sin_addr));
+			while (parse_a(u, 65535, d, strlen(d), ž++).s_addr);
+			if (i.s_addr == a.s_addr) /* if multithread, change printf to write. */
+				printf("\tWORKING");
 			if (i.s_addr && i.s_addr != a.s_addr)
-				printf("LYING %s WITH %s\n", inet_ntoa(f.sin_addr), inet_ntoa(i));
+				printf("\tLYINGWITH\t%s", inet_ntoa(i));
+			if (--ž > 1)
+				printf("\tMORETHANONE\t%d", ž);
+			if (!i.s_addr)
+				printf("\tNOA");
+			printf("\n");
 
 		}
 		if (z.tv_sec)
-- 
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