From f1a232fd863e0e081a8edf8b1859a9417debb7c7 Mon Sep 17 00:00:00 2001
From: Florin Coras <fcoras@cisco.com>
Date: Thu, 2 Feb 2023 22:56:03 -0800
Subject: [PATCH] vcl: add ldp implementation for recvmmsg

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I7322abc3d3b0aa81399667bf02b03786fc62c958
---
 src/vcl/ldp.c | 70 +++++++++++++++++++++++++++++++++--------------------------
 1 file changed, 39 insertions(+), 31 deletions(-)

diff --git a/src/vcl/ldp.c b/src/vcl/ldp.c
index 482af3f1f82..ade19a73a94 100644
--- a/src/vcl/ldp.c
+++ b/src/vcl/ldp.c
@@ -1843,47 +1843,55 @@ int
 recvmmsg (int fd, struct mmsghdr *vmessages,
 	  unsigned int vlen, int flags, struct timespec *tmo)
 {
-  ssize_t size;
-  const char *func_str;
-  u32 sh = ldp_fd_to_vlsh (fd);
+  ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
+  u32 sh;
 
   ldp_init_check ();
 
+  sh = ldp_fd_to_vlsh (fd);
+
   if (sh != VLS_INVALID_HANDLE)
     {
-      clib_warning ("LDP<%d>: LDP-TBD", getpid ());
-      errno = ENOSYS;
-      size = -1;
-    }
-  else
-    {
-      func_str = "libc_recvmmsg";
+      struct mmsghdr *mh;
+      ssize_t rv = 0;
+      u32 nvecs = 0;
+      f64 time_out;
 
-      if (LDP_DEBUG > 2)
-	clib_warning ("LDP<%d>: fd %d (0x%x): calling %s(): "
-		      "vmessages %p, vlen %u, flags 0x%x, tmo %p",
-		      getpid (), fd, fd, func_str, vmessages, vlen,
-		      flags, tmo);
-
-      size = libc_recvmmsg (fd, vmessages, vlen, flags, tmo);
-    }
-
-  if (LDP_DEBUG > 2)
-    {
-      if (size < 0)
+      if (PREDICT_FALSE (ldpw->clib_time.init_cpu_time == 0))
+	clib_time_init (&ldpw->clib_time);
+      if (tmo)
 	{
-	  int errno_val = errno;
-	  perror (func_str);
-	  clib_warning ("LDP<%d>: ERROR: fd %d (0x%x): %s() failed! "
-			"rv %d, errno = %d", getpid (), fd, fd,
-			func_str, size, errno_val);
-	  errno = errno_val;
+	  time_out = (f64) tmo->tv_sec + (f64) tmo->tv_nsec / (f64) 1e9;
+	  time_out += clib_time_now (&ldpw->clib_time);
 	}
       else
-	clib_warning ("LDP<%d>: fd %d (0x%x): returning %d (0x%x)",
-		      getpid (), fd, fd, size, size);
+	{
+	  time_out = (f64) ~0;
+	}
+
+      while (nvecs < vlen)
+	{
+	  mh = &vmessages[nvecs];
+	  rv = recvmsg (fd, &mh->msg_hdr, flags);
+	  if (rv > 0)
+	    {
+	      mh->msg_len = rv;
+	      nvecs += 1;
+	      continue;
+	    }
+
+	  if (!time_out || clib_time_now (&ldpw->clib_time) >= time_out)
+	    break;
+
+	  usleep (1);
+	}
+
+      return nvecs > 0 ? nvecs : rv;
+    }
+  else
+    {
+      return libc_recvmmsg (fd, vmessages, vlen, flags, tmo);
     }
-  return size;
 }
 #endif
 
-- 
2.16.6