[lttng-dev] [PATCH lttng-tools 01/24] Implement lttng_strncpy safe string copy

[Mathieu Desnoyers]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
---
 src/common/macros.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/common/macros.h b/src/common/macros.h
index 308d3d5..6147eff 100644
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -20,6 +20,7 @@
 #define _MACROS_H
 
 #include <stdlib.h>
+#include <string.h>
 
 /*
  * Takes a pointer x and transform it so we can use it to access members
@@ -76,4 +77,25 @@ void *zmalloc(size_t len)
 #define LTTNG_HIDDEN __attribute__((visibility("hidden")))
 #endif
 
+/*
+ * lttng_strncpy returns 0 on success, or nonzero on failure.
+ * It checks that the @src string fits into @dest_len before performing
+ * the copy. On failure, no copy has been performed.
+ */
+static inline
+int lttng_strncpy(char *dest, const char *src, size_t dest_len)
+{
+	if (strlen(src) >= dest_len) {
+		return -1;
+	}
+	strncpy(dest, src, dest_len);
+	/*
+	 * Be extra careful and put final \0 at the end after strncpy(),
+	 * even though we checked the length before. This makes Coverity
+	 * happy.
+	 */
+	dest[dest_len - 1] = '\0';
+	return 0;
+}
+
 #endif /* _MACROS_H */
-- 
2.1.4