Add a minimal option and gt_open_sock

glorytun.c

@@ -7,15 +7,67 @@
 #include <sys/ioctl.h>
 #include <sys/fcntl.h>
 #include <sys/socket.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
 
 #include <linux/if.h>
 #include <linux/if_tun.h>
 
-#define GT_NAME        "glorytun"
 #define GT_BUFFER_SIZE (256*1024)
 
 volatile sig_atomic_t running;
 
+static int gt_open_sock (char *host, char *port, int listener)
+{
+    struct addrinfo hints = {
+        .ai_family = AF_UNSPEC,
+        .ai_socktype = SOCK_STREAM,
+        .ai_protocol = IPPROTO_TCP,
+        .ai_flags = AI_PASSIVE,
+    };
+
+    struct addrinfo *ai, *res = NULL;
+
+    if (getaddrinfo(host, port, &hints, &res)) {
+        printf("host not found\n");
+        return -1;
+    }
+
+    int fd = -1;
+
+    for (ai=res; ai; ai=ai->ai_next) {
+        fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+
+        if (fd==-1)
+            continue;
+
+        int ret;
+
+        if (listener) {
+            ret = bind(fd, ai->ai_addr, ai->ai_addrlen);
+            if (!ret)
+                ret = listen(fd, 1);
+        } else {
+            ret = connect(fd, ai->ai_addr, ai->ai_addrlen);
+        }
+
+        if (!ret)
+            break;
+
+        if (errno)
+            printf("socket: %m\n");
+
+        close(fd);
+
+        fd = -1;
+    }
+
+    freeaddrinfo(res);
+
+    return fd;
+}
+
 static int gt_open_tun (char *name)
 {
     int fd = open("/dev/net/tun", O_RDWR);
@@ -115,17 +167,62 @@ static inline int write_from_buffer (int fd, buffer_t *buffer)
     return 1;
 }
 
+enum option_type {
+    option_flag,
+    option_string,
+};
+
+struct option {
+    char *name;
+    void *data;
+    enum option_type type;
+};
+
+static void option (int argc, char **argv, int n, struct option *opt)
+{
+    for (int i=0; i<argc; i++) {
+        for (int k=0; k<n; k++) {
+            if (str_cmp(opt[k].name, argv[i]))
+                continue;
+            switch (opt[k].type) {
+            case option_flag:
+                *(int *)opt[k].data = 1;
+                break;
+            case option_string:
+                *(char **)opt[k].data = argv[++i];
+                break;
+            }
+        }
+    }
+}
+
 int main (int argc, char **argv)
 {
     gt_set_signal();
 
-    int tun_fd = gt_open_tun(GT_NAME);
+    char *host = NULL;
+    char *port = "5000";
+    char *dev  = "glorytun";
+    int listener = 0;
 
-    if (tun_fd==-1)
+    struct option opts[] = {
+        { "dev",      &dev,      option_string },
+        { "host",     &host,     option_string },
+        { "port",     &port,     option_string },
+        { "listener", &listener, option_flag   },
+    };
+
+    option(argc, argv, COUNT(opts), opts);
+
+    int tun_fd  = gt_open_tun(dev);
+    int sock_fd = gt_open_sock(host, port, listener);
+
+    if (tun_fd==-1 || sock_fd==-1)
         return 1;
 
     struct pollfd fds[] = {
-        { .fd = tun_fd, .events = POLLIN },
+        { .fd = tun_fd,  .events = POLLIN },
+        { .fd = sock_fd, .events = POLLIN },
     };
 
     buffer_t input;