tcp raw socket, mkdir simple_examples

Author: Your Name

getaddrinfo.c simple_examples/getaddrinfo.cgetaddrinfo.c renamed to simple_examples/getaddrinfo.c

@@ -12,9 +12,9 @@ int main(int argc, char **argv)
 	struct addrinfo hints, *result, *tmp;
 	struct sockaddr_in *sock_addr;
 	int res;
-	hints.ai_flags = AI_PASSIVE;
+	hints.ai_flags = 0;
 	hints.ai_family = AF_INET;
-	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_socktype = SOCK_RAW;
 	hints.ai_protocol = 0;
 	hints.ai_addrlen = 0;
 	hints.ai_canonname = NULL;

simple_examples/tcp.c

@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <netdb.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+
+int main(int argc, char *argv[])
+{
+	struct addrinfo *hints, *answ, *tmp;
+	struct tcphdr *send_frame;
+	int sock, ret;
+	ssize_t send_cnt;
+	if (argc < 2) {
+		fprintf(stderr, "need host name\n");
+		exit(1);
+	}
+	if ( (hints = calloc(1, sizeof(struct addrinfo))) == NULL) {
+		perror("calloc");
+		exit(1);
+	}
+	if ( (send_frame = calloc(1, sizeof(struct tcphdr))) == NULL) {
+		perror("malloc");
+		exit(1);
+	}
+	hints->ai_family = AF_INET;
+	hints->ai_socktype = SOCK_RAW;
+	hints->ai_protocol = IPPROTO_TCP;
+	if ( (ret = getaddrinfo(argv[1], NULL, hints, &answ)) != 0) {
+		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ret));
+		exit(1);
+	}
+	for (tmp = answ; tmp != NULL; tmp = tmp->ai_next) {
+		if ( (sock = socket(tmp->ai_family, tmp->ai_socktype,
+						tmp->ai_protocol)) == -1) {
+			perror("socket");
+			if (tmp == NULL) { /*walk around the whole list*/
+				fprintf(stderr, "failed open socket\n");
+				exit(1);
+			} else {
+				continue;
+			}
+		} else {
+			printf("was openned sock with addr: %s\n",
+					inet_ntoa(((struct sockaddr_in *)tmp->
+						ai_addr)->sin_addr) );
+			break;
+		}
+	}
+	/*old method:
+	if ( (sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1) {
+		perror("socket");
+		exit(1);
+	}
+	*/
+	send_cnt = sendto(sock, send_frame, sizeof(struct tcphdr), 0,
+			tmp->ai_addr, tmp->ai_addrlen);
+	if (send_cnt == -1) {
+		perror("sendto");
+		exit(1);
+	}
+	return 0;
+}