xtables-restore: Introduce rule counter tokenizer function

The same piece of code appears three times, introduce a function to take
care of tokenizing and error reporting.

Pass buffer pointer via reference so it can be updated to point to after
the counters (if found).

While being at it, drop pointless casting when passing pcnt/bcnt to
add_argv().

Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/iptables/xshared.c b/iptables/xshared.c
index 5e6cd4ae..ba723f59 100644
--- a/iptables/xshared.c
+++ b/iptables/xshared.c
@@ -373,6 +373,43 @@ int parse_counters(const char *string, struct xt_counters *ctr)
 	return ret == 2;
 }
 
+/* Tokenize counters argument of typical iptables-restore format rule.
+ *
+ * If *bufferp contains counters, update *pcntp and *bcntp to point at them,
+ * change bytes after counters in *bufferp to nul-bytes, update *bufferp to
+ * point to after the counters and return true.
+ * If *bufferp does not contain counters, return false.
+ * If syntax is wrong in *bufferp, call xtables_error() and hence exit().
+ * */
+bool tokenize_rule_counters(char **bufferp, char **pcntp, char **bcntp, int line)
+{
+	char *ptr, *buffer = *bufferp, *pcnt, *bcnt;
+
+	if (buffer[0] != '[')
+		return false;
+
+	/* we have counters in our input */
+
+	ptr = strchr(buffer, ']');
+	if (!ptr)
+		xtables_error(PARAMETER_PROBLEM, "Bad line %u: need ]\n", line);
+
+	pcnt = strtok(buffer+1, ":");
+	if (!pcnt)
+		xtables_error(PARAMETER_PROBLEM, "Bad line %u: need :\n", line);
+
+	bcnt = strtok(NULL, "]");
+	if (!bcnt)
+		xtables_error(PARAMETER_PROBLEM, "Bad line %u: need ]\n", line);
+
+	*pcntp = pcnt;
+	*bcntp = bcnt;
+	/* start command parsing after counter */
+	*bufferp = ptr + 1;
+
+	return true;
+}
+
 inline bool xs_has_arg(int argc, char *argv[])
 {
 	return optind < argc &&