utils: Introduce and use nftnl_set_str_attr()

The function consolidates the necessary code when assigning to string
pointer attributes, namely:

* Conditional free of the previous value
* Allocation of new value
* Checking for memory allocation errors
* Setting respective flag bit

A new feature previously missing in all call sites is respecting
data_len in case the buffer up to that point did not contain a NUL-char.

Signed-off-by: Phil Sutter <phil@nwl.cc>

1 files changed, 4 insertions, 14 deletions

diff --git a/src/set.c b/src/set.c
index a732bc0..07e332d 100644
--- a/src/set.c
+++ b/src/set.c
@@ -146,21 +146,11 @@ int nftnl_set_set_data(struct nftnl_set *s, uint16_t attr, const void *data,
 
 	switch(attr) {
 	case NFTNL_SET_TABLE:
-		if (s->flags & (1 << NFTNL_SET_TABLE))
-			xfree(s->table);
-
-		s->table = strdup(data);
-		if (!s->table)
-			return -1;
-		break;
+		return nftnl_set_str_attr(&s->table, &s->flags,
+					  attr, data, data_len);
 	case NFTNL_SET_NAME:
-		if (s->flags & (1 << NFTNL_SET_NAME))
-			xfree(s->name);
-
-		s->name = strdup(data);
-		if (!s->name)
-			return -1;
-		break;
+		return nftnl_set_str_attr(&s->name, &s->flags,
+					  attr, data, data_len);
 	case NFTNL_SET_HANDLE:
 		memcpy(&s->handle, data, sizeof(s->handle));
 		break;