Comments and cleanup

examples/socks5proxy.c

@@ -42,90 +42,73 @@ int auth_fn(const char *user, const char* pass) {
     return 1;
 }
 
-// forwards input to output. return on error (connection closed)
+// forwards input to output. signal and return on error (connection closed)
 coroutine void forward(int in_s, int out_s, int ch) {
     while (1) {
         uint8_t d[1];
-        int err = brecv(in_s, d, 1, -1);
-        if (err) break ;
-        err = bsend(out_s, d, 1, -1);
-        if(err) break;
+        if(brecv(in_s, d, 1, -1)) break;
+        if(bsend(out_s, d, 1, -1)) break;
     }
     chdone(ch);
     return;
 }
 
 coroutine void do_proxy(int s) {
-    int err;
     if((!auth_user) || (!auth_pass)){
-        err = socks5_proxy_auth(s, NULL, -1);
+        if(socks5_proxy_auth(s, NULL, -1)) goto in_close;
     } else {
-        err = socks5_proxy_auth(s, auth_fn, -1);
+        if(socks5_proxy_auth(s, auth_fn, -1)) goto in_close;
     }
-    if(err) goto in_close;
 
     struct ipaddr addr;
     int cmd = socks5_proxy_recvcommand(s, &addr, -1);
-    if(cmd != SOCKS5_CONNECT) goto in_close;
+    if(cmd != SOCKS5_CONNECT) {
+        socks5_proxy_sendreply(s, SOCKS5_COMMAND_NOT_SUPPORTED, &addr, -1);
+        goto in_close;
+    }
 
     int s_rem = tcp_connect(&addr, -1);
     if(s_rem < 0) goto in_close;
 
-    err = ipaddr_remote(&addr, "0.0.0.0", 0, IPADDR_IPV4, -1);
-    if(err) goto both_close;
+    if(ipaddr_remote(&addr, "0.0.0.0", 0, IPADDR_IPV4, -1)) goto both_close;
 
-    err = socks5_proxy_sendreply(s, SOCKS5_SUCCESS, &addr, -1);
-    if(err) goto both_close;
+    if(socks5_proxy_sendreply(s, SOCKS5_SUCCESS, &addr, -1)) goto both_close;
 
     // channels for outboud, inbound to signal done (to close connection)
     int och[2], ich[2];
-    err = chmake(och);
-    if(err) goto both_close;
-    err = chmake(ich);
-    if(err) goto both_close;
+    if(chmake(och)) goto both_close;
+    if(chmake(ich)) goto both_close;
 
+    // start coroutines to handle inbound and outbound forwarding
     int ob = go(forward(s, s_rem, och[1]));
     if(ob < 0) goto both_close;
     int ib = go(forward(s_rem, s, ich[1]));
     if(ib < 0) goto both_close;
 
-    struct chclause cc[] = {{CHRECV, och[0], &err, 1},
-                            {CHRECV, ich[0], &err, 1}};
-    // wait for message in channel - one side closed
-    int c = choose(cc, 2, -1);
-    switch(c) {
-        // one side closed, close the other
+    // wait for message in channel - one side closed, tcp_done the other
+    struct chclause cc[] = {{CHRECV, och[0], &cmd, 1},
+                            {CHRECV, ich[0], &cmd, 1}};
+    switch(choose(cc, 2, -1)) {
         case 0:
-            err = bundle_wait(ob, -1);
-            if(err) break;
-            tcp_done(s, -1);
+            if(bundle_wait(ob, -1)) break;
             tcp_done(s_rem, -1);
-            err = bundle_wait(ib, -1);
-            if(err) break;
-            //tcp_close(s_rem, -1);
+            bundle_wait(ib, -1);
             break;
         case 1:
-            err = bundle_wait(ib, -1);
-            if(err) break;
-            tcp_done(s_rem, -1);
+            if(bundle_wait(ib, -1)) break;
             tcp_done(s, -1);
-            err = bundle_wait(ob, -1);
-            if(err) break;
-            //tcp_close(s, -1);
+            bundle_wait(ob, -1);
             break;
         case -1:
-            // error
             break;
         default:
             // unexpected answer
             assert(0);
     }
-
 both_close:
     tcp_close(s_rem, -1);
 in_close:
     tcp_close(s, -1);
-
     return;
 }
 
@@ -135,7 +118,6 @@ int main(int argc, char** argv) {
         auth_user = argv[1];
         auth_pass = argv[2];
     }
-
     int workers = bundle();
     struct ipaddr addr;
     int rc = ipaddr_local(&addr, NULL, 1080, 0);
@@ -146,8 +128,6 @@ int main(int argc, char** argv) {
     while(1) {
         struct ipaddr caddr;
         int s = tcp_accept(ls, &caddr, -1);
-        char caddr_str[IPADDR_MAXSTRLEN];
-        ipaddr_str(&caddr, caddr_str);
         assert(s >= 0);
         rc = bundle_go(workers, do_proxy(s));
         assert(rc == 0);