[tor-commits] [tor-browser/tor-browser-52.3.0esr-7.5-2] Bug 1355274 - Polyfill SOCK_DGRAM socketpairs with SOCK_SEQPACKET, for libasyncns. r=gcp

[gk at torproject.org]

commit d63e9b803e99682fc561e60c81cbe7b793b7b70f
Author: Jed Davis <jld at mozilla.com>
Date:   Tue Apr 11 20:55:34 2017 -0600

    Bug 1355274 - Polyfill SOCK_DGRAM socketpairs with SOCK_SEQPACKET, for libasyncns. r=gcp
    
    MozReview-Commit-ID: 2DeklSGsjUV
    
    --HG--
    extra : rebase_source : 8a202c23dc9a3ddede49b08ce1e0792dfb40bdbf
---
 security/sandbox/linux/SandboxFilter.cpp | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/security/sandbox/linux/SandboxFilter.cpp b/security/sandbox/linux/SandboxFilter.cpp
index 7e1771a62665..5ddd58029e85 100644
--- a/security/sandbox/linux/SandboxFilter.cpp
+++ b/security/sandbox/linux/SandboxFilter.cpp
@@ -496,6 +496,16 @@ class ContentSandboxPolicy : public SandboxPolicyCommon {
     return 0;
   }
 
+  static intptr_t SocketpairDatagramTrap(ArgsRef aArgs, void* aux) {
+    auto fds = reinterpret_cast<int*>(aArgs.args[3]);
+    // Return sequential packet sockets instead of the expected
+    // datagram sockets; see bug 1355274 for details.
+    if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds) != 0) {
+      return -errno;
+    }
+    return 0;
+  }
+
 public:
   explicit ContentSandboxPolicy(SandboxBrokerClient* aBroker):mBroker(aBroker) { }
   virtual ~ContentSandboxPolicy() { }
@@ -508,6 +518,7 @@ public:
     switch(aCall) {
     case SYS_RECVFROM:
     case SYS_SENDTO:
+    case SYS_SENDMMSG: // libresolv via libasyncns; see bug 1355274
       return Some(Allow());
 
     case SYS_SOCKETPAIR: {
@@ -517,9 +528,12 @@ public:
         return Some(Allow());
       }
       Arg<int> domain(0), type(1);
-      return Some(If(AllOf(domain == AF_UNIX,
-                           AnyOf(type == SOCK_STREAM, type == SOCK_SEQPACKET)),
-                     Allow())
+      return Some(If(domain == AF_UNIX,
+                     Switch(type)
+                     .Case(SOCK_STREAM, Allow())
+                     .Case(SOCK_SEQPACKET, Allow())
+                     .Case(SOCK_DGRAM, Trap(SocketpairDatagramTrap, nullptr))
+                     .Default(InvalidSyscall()))
                   .Else(InvalidSyscall()));
     }