From 3cdc25ffbaa572639f99e197172c568e4324bc03 Mon Sep 17 00:00:00 2001
From: Ole Troan <ot@cisco.com>
Date: Thu, 17 Aug 2017 11:07:33 +0200
Subject: [PATCH] API: More gracefully fail when opening shared memory segment
 fails.

API clients would fail with an ASSERT (and core dump) whenever
the API shared memory segment could not be opened.
This returns an error value to the client's connect instead.

Change-Id: Id122a3a090b24b139c382ae09f341bde61fd2540
Signed-off-by: Ole Troan <ot@cisco.com>
---
 src/svm/svm.c                  | 13 ++++++++-----
 src/svm/svm_common.h           |  2 +-
 src/vlibmemory/memory_shared.c |  8 ++++++--
 3 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/svm/svm.c b/src/svm/svm.c
index 0442ecb2950..663324e0a77 100644
--- a/src/svm/svm.c
+++ b/src/svm/svm.c
@@ -733,7 +733,7 @@ svm_mutex_cleanup (void)
     }
 }
 
-static void
+static int
 svm_region_init_internal (svm_map_region_args_t * a)
 {
   svm_region_t *rp;
@@ -742,7 +742,7 @@ svm_region_init_internal (svm_map_region_args_t * a)
 
   /* guard against klutz calls */
   if (root_rp)
-    return;
+    return -1;
 
   root_rp_refcount++;
 
@@ -757,7 +757,8 @@ svm_region_init_internal (svm_map_region_args_t * a)
   a->baseva += randomize_baseva;
 
   rp = svm_map_region (a);
-  ASSERT (rp);
+  if (!rp)
+    return -1;
 
   region_lock (rp, 3);
 
@@ -778,6 +779,8 @@ svm_region_init_internal (svm_map_region_args_t * a)
     }
   region_unlock (rp);
   root_rp = rp;
+
+  return 0;
 }
 
 void
@@ -797,7 +800,7 @@ svm_region_init (void)
   svm_region_init_internal (a);
 }
 
-void
+int
 svm_region_init_chroot (const char *root_path)
 {
   svm_map_region_args_t _a, *a = &_a;
@@ -811,7 +814,7 @@ svm_region_init_chroot (const char *root_path)
   a->uid = 0;
   a->gid = 0;
 
-  svm_region_init_internal (a);
+  return svm_region_init_internal (a);
 }
 
 void
diff --git a/src/svm/svm_common.h b/src/svm/svm_common.h
index 1f184432967..1f6d83c0a37 100644
--- a/src/svm/svm_common.h
+++ b/src/svm/svm_common.h
@@ -110,7 +110,7 @@ typedef struct
 
 void *svm_region_find_or_create (svm_map_region_args_t * a);
 void svm_region_init (void);
-void svm_region_init_chroot (const char *root_path);
+int svm_region_init_chroot (const char *root_path);
 void svm_region_init_chroot_uid_gid (const char *root_path, int uid, int gid);
 void svm_region_init_args (svm_map_region_args_t * a);
 void svm_region_exit (void);
diff --git a/src/vlibmemory/memory_shared.c b/src/vlibmemory/memory_shared.c
index 9bab65730ef..fbdabd06e36 100644
--- a/src/vlibmemory/memory_shared.c
+++ b/src/vlibmemory/memory_shared.c
@@ -337,7 +337,7 @@ vl_map_shmem (const char *region_name, int is_vlib)
   void *oldheap;
   vl_shmem_hdr_t *shmem_hdr = 0;
   api_main_t *am = &api_main;
-  int i;
+  int i, rv;
   struct timespec ts, tsrem;
   u32 vlib_input_queue_length;
 
@@ -352,7 +352,11 @@ vl_map_shmem (const char *region_name, int is_vlib)
     }
 
   if (is_vlib == 0)
-    svm_region_init_chroot (am->root_path);
+    {
+      rv = svm_region_init_chroot (am->root_path);
+      if (rv)
+	return rv;
+    }
 
   if (a->root_path != NULL)
     {
-- 
2.16.6