[libvirt] [PATCH] log: actually do substring matches with fnmatch

[Daniel P. Berrangé]

Historically we matched log filters with strstr(), and when switching to
fnmatch in cbb0fd3cfdc287f6f4653ef1f04a7cfb2ea51b27, it was stated that
we would continue to match substrings, with "foo" being equivalent to
"*foo*". Unfortuntely I forget to provide the code to actually make that
happen. This fixes it to prepend and append "*" if not already present in
the user's pattern.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/util/virlog.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/util/virlog.c b/src/util/virlog.c
index be9fc0cf78..d548010b10 100644
--- a/src/util/virlog.c
+++ b/src/util/virlog.c
@@ -1409,6 +1409,8 @@ virLogFilterNew(const char *match,
 {
     virLogFilterPtr ret = NULL;
     char *mdup = NULL;
+    size_t mlen = strlen(match);
+    size_t off = 0;
 
     virCheckFlags(VIR_LOG_STACK_TRACE, NULL);
 
@@ -1418,9 +1420,19 @@ virLogFilterNew(const char *match,
         return NULL;
     }
 
-    if (VIR_STRDUP_QUIET(mdup, match) < 0)
+    if (VIR_ALLOC_N_QUIET(mdup, mlen + 3) < 0)
         return NULL;
 
+    if (match[0] != '*') {
+        mdup[off++] = '*';
+    }
+    memcpy(mdup + off, match, mlen + 1);
+    off += mlen;
+    if (match[mlen - 1] != '*') {
+        mdup[off++] = '*';
+        mdup[off++] = '\0';
+    }
+
     if (VIR_ALLOC_QUIET(ret) < 0) {
         VIR_FREE(mdup);
         return NULL;
-- 
2.17.0