Working bot answering PING, and its C wrapper.

1 files changed, 65 insertions, 0 deletions

diff --git a/src/tcp.c b/src/tcp.c
new file mode 100644
index 0000000..659a39e
--- /dev/null
+++ b/src/tcp.c
@@ -0,0 +1,65 @@
+#include <arpa/inet.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "tcp.h"
+
+int tcp_connect(const char* const host, const int port)
+{
+    char ip[INET6_ADDRSTRLEN];
+    hostname_to_ip(host , ip);
+    printf("%s resolved to %s\n" , host, ip);
+
+    struct sockaddr_in sa;
+    int sd = socket(AF_INET, SOCK_STREAM, 0);
+    memset(&sa, '\0', sizeof(sa));
+    sa.sin_family = AF_INET;
+    sa.sin_port = htons(port);
+    inet_pton(AF_INET, ip, &sa.sin_addr);
+
+    int err = connect(sd, (struct sockaddr *) &sa, sizeof(sa));
+    if (err < 0) {
+        fprintf(stderr, "Couldn't connect %s:%d : %s\n", host, port, strerror(errno));
+        return -1;
+    }
+
+    return sd;
+}
+
+void tcp_close(const int sd)
+{
+    shutdown(sd, SHUT_RDWR);
+    close(sd);
+}
+
+int hostname_to_ip(const char* const hostname, char *ip)
+{
+    struct addrinfo hints, *servinfo; //, *p;
+    struct sockaddr_in *h;
+    int rv, ret = 0;
+
+    memset(&hints, 0, sizeof hints);
+    hints.ai_family = AF_UNSPEC; // use AF_INET6 to force IPv6
+    hints.ai_socktype = SOCK_STREAM;
+
+    if ( (rv = getaddrinfo( hostname , "http" , &hints , &servinfo)) != 0) 
+    {
+        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
+        ret = 1;
+    } else {
+        //// loop through all the results and connect to the first we can
+        //for(p = servinfo; p != NULL; p = p->ai_next)
+        //{
+        //    h = (struct sockaddr_in *) p->ai_addr;
+        //    strcpy(ip , inet_ntoa( h->sin_addr ) );
+        //}
+        h = (struct sockaddr_in *) servinfo->ai_addr;
+        strcpy(ip, inet_ntoa(h->sin_addr));
+    }
+
+    freeaddrinfo(servinfo); // all done with this structure
+    return ret;
+}