Support LOCAL_PEEREID (NetBSD) and getpeereid() (FreeBSD)

* configure.ac: check for LOCAL_PEEREID and getpeereid().
* src/assuan-socket-server.c (accept_connection_bottom): make use of
LOCAL_PEEREID and getpeereid().
--

For use with assuan_get_peercred(). Note that getpeereid() does not
set the PID member. LOCAL_PEEREID is checked before getpeereid()
since NetBSD has both of these. SO_PEERCRED is still checked first.

[Second revision]
This revision adds support for LOCAL_PEEREID which NetBSD uses. Its
tested against NetBSD 6.0 and may work without problems with earlier
versions. FreeBSD uses getpeereid() which does not have PID support.
Recent OpenBSD versions do support SO_PEERCRED and old versions have
getpeereid() but also may have LOCAL_PEEREID (not sure).

2 files changed, 47 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index b420f48..5a2a8d6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -367,9 +367,35 @@ AC_CACHE_VAL(assuan_cv_sys_so_peercred,
           assuan_cv_sys_so_peercred=no)
        ])
 AC_MSG_RESULT($assuan_cv_sys_so_peercred)
+
 if test $assuan_cv_sys_so_peercred = yes; then
   AC_DEFINE(HAVE_SO_PEERCRED, 1,
             [Defined if SO_PEERCRED is supported (Linux specific)])
+else
+  #
+  # Check for the getsockopt LOCAL_PEEREID (NetBSD)
+  #
+  AC_MSG_CHECKING(for LOCAL_PEEREID)
+  AC_CACHE_VAL(assuan_cv_sys_so_local_peereid,
+      [AC_TRY_COMPILE([#include <sys/socket.>
+         #include <sys/un.h>],
+         [struct unpcbid unp;
+          int unpl = sizeof unp;
+          getsockopt (1, SOL_SOCKET, LOCAL_PEEREID, &unp, &unpl);],
+          assuan_cv_sys_so_local_peereid=yes,
+          assuan_cv_sys_so_local_peereid=no)
+       ])
+  AC_MSG_RESULT($assuan_cv_sys_so_local_peereid)
+
+  if test $assuan_cv_sys_so_local_peereid = yes; then
+    AC_DEFINE(HAVE_LOCAL_PEEREID, 1,
+              [Defined if LOCAL_PEEREID is supported (NetBSD specific)])
+  else
+    #
+    # FreeBSD
+    #
+    AC_CHECK_FUNCS([getpeereid])
+  fi
 fi
 
 
diff --git a/src/assuan-socket-server.c b/src/assuan-socket-server.c
index 27994a2..1e8e541 100644
--- a/src/assuan-socket-server.c
+++ b/src/assuan-socket-server.c
@@ -74,6 +74,27 @@ accept_connection_bottom (assuan_context_t ctx)
            ctx->pid = cr.pid;
       }
   }
+#elif defined(HAVE_LOCAL_PEEREID)
+  {
+    struct unpcbid unp;
+    socklen_t unpl = sizeof unp;
+
+    if (getsockopt(fd, 0, LOCAL_PEEREID, &unp, &unpl) != -1)
+      {
+	ctx->peercred.pid = unp.unp_pid;
+	ctx->peercred.uid = unp.unp_euid;
+	ctx->peercred.gid = unp.unp_egid;
+	ctx->peercred_valid = 1;
+      }
+  }
+#elif defined(HAVE_GETPEEREID)
+  {
+    if (getpeereid(fd, &ctx->peercred.uid, &ctx->peercred.gid) != -1)
+      {
+	ctx->peercred.pid = ASSUAN_INVALID_PID;
+	ctx->peercred_valid = 1;
+      }
+  }
 #endif
 
   ctx->inbound.fd = fd;