From: Mark Huang <mlhuang@cs.princeton.edu>
Date: Wed, 20 Oct 2004 02:33:15 +0000 (+0000)
Subject: - PL2525 fix: implement SO_SETXID (reset the context ID of an existing
X-Git-Tag: before-enable-kexec-patch~35
X-Git-Url: http://git.onelab.eu/?a=commitdiff_plain;h=272fe31225f788b95c91d35481c58ead8afa351d;p=linux-2.6.git

- PL2525 fix: implement SO_SETXID (reset the context ID of an existing
  socket). Callable by root context only. To avoid having to register a
  new sockopt number, #define SO_SETXID to be SO_PASSCRED (which is not
  usually callable by setsockopt()):

#if !defined(SO_SETXID)
#define SO_SETXID SO_PASSCRED
#endif

int xid;
setsockopt(fd, SOL_SOCKET, SO_SETXID, &xid, sizeof(xid));
---

diff --git a/net/core/sock.c b/net/core/sock.c
index d5b2d9105..266397922 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -331,6 +331,18 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 				clear_bit(SOCK_PASS_CRED, &sock->flags);
 			break;
 
+		case SO_SETXID:
+			if (current->xid) {
+				ret = -EPERM;
+				break;
+			}
+			if (val < 0 || val > MAX_S_CONTEXT) {
+				ret = -EINVAL;
+				break;
+			}
+			sk->sk_xid = val;
+			break;
+
 		case SO_TIMESTAMP:
 			sk->sk_rcvtstamp = valbool;
 			if (valbool)