From: Vlad Badoiu <vlad_andrei.badoiu@upb.ro>
Date: Tue, 18 Jan 2022 20:16:12 +0000 (+0200)
Subject: lwip: Add dumb socketpair implementation
X-Git-Tag: RELEASE-0.7.0^0
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=40f2c7731e2f00042d6b13b134e6b07ebe769c49;p=unikraft%2Flibs%2Flwip.git

lwip: Add dumb socketpair implementation

We add a dumb implementation of socketpair until
posix-socket is upstreamed. Since we have no SMP
available on Unikraft, this implementation works
well.

Signed-off-by: Vlad-Andrei Badoiu <vlad_andrei.badoiu@upb.ro>
Reviewed-by: Sergiu Moga <sergiu.moga@protonmail.com>
Approved-by: Razvan Deaconescu <razvan.deaconescu@cs.pub.ro>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Pull-Request: #15
---

diff --git a/sockets.c b/sockets.c
index 7db82c7..8f25e3f 100644
--- a/sockets.c
+++ b/sockets.c
@@ -890,8 +890,54 @@ EXIT:
 	return ret;
 }
 
-int socketpair(int domain, int type, int protocol, int sv[2])
+int socketpair(int domain, int type, int protocol, int socks[2])
 {
+	int listener;
+	int reuse = 1;
+	union {
+		struct sockaddr_in inaddr;
+		struct sockaddr addr;
+	} a;
+
+	socklen_t addrlen = sizeof(a.inaddr);
+
+	listener = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+
+	memset(&a, 0, sizeof(a));
+	a.inaddr.sin_family = AF_INET;
+	a.inaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	a.inaddr.sin_port = 0;
+
+	if (setsockopt(listener, SOL_SOCKET, SO_REUSEADDR,
+	       (char*) &reuse, (socklen_t) sizeof(reuse)) == -1)
+		goto error;
+
+	if  (bind(listener, &a.addr, sizeof(a.inaddr)) < 0)
+		goto error;
+
+	if  (getsockname(listener, &a.addr, &addrlen) < 0)
+		goto error;
+
+	if (listen(listener, 1) < 0)
+		goto error;
+
+	socks[0] = socket(AF_INET, SOCK_STREAM, 0);
+
+	if (socks[0] < 0)
+		goto error;
+
+	if (connect(socks[0], &a.addr, sizeof(a.inaddr)) < 0)
+		goto error;
+
+	socks[1] = accept(listener, NULL, NULL);
+
+	if (socks[1] < 0)
+		goto error;
+
+	close(listener);
+	return 0;
+
+error:
 	errno = ENOTSUP;
 	return -1;
 }