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path: root/net/ipv4/cipso_ipv4.c
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Diffstat (limited to 'net/ipv4/cipso_ipv4.c')
-rw-r--r--net/ipv4/cipso_ipv4.c45
1 files changed, 34 insertions, 11 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 2ce5b693a8b..e1f18489db1 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -92,6 +92,33 @@ int cipso_v4_rbm_optfmt = 0;
int cipso_v4_rbm_strictvalid = 1;
/*
+ * Protocol Constants
+ */
+
+/* Maximum size of the CIPSO IP option, derived from the fact that the maximum
+ * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
+#define CIPSO_V4_OPT_LEN_MAX 40
+
+/* Length of the base CIPSO option, this includes the option type (1 byte), the
+ * option length (1 byte), and the DOI (4 bytes). */
+#define CIPSO_V4_HDR_LEN 6
+
+/* Base length of the restrictive category bitmap tag (tag #1). */
+#define CIPSO_V4_TAG_RBM_BLEN 4
+
+/* Base length of the enumerated category tag (tag #2). */
+#define CIPSO_V4_TAG_ENUM_BLEN 4
+
+/* Base length of the ranged categories bitmap tag (tag #5). */
+#define CIPSO_V4_TAG_RNG_BLEN 4
+/* The maximum number of category ranges permitted in the ranged category tag
+ * (tag #5). You may note that the IETF draft states that the maximum number
+ * of category ranges is 7, but if the low end of the last category range is
+ * zero then it is possibile to fit 8 category ranges because the zero should
+ * be omitted. */
+#define CIPSO_V4_TAG_RNG_CAT_MAX 8
+
+/*
* Helper Functions
*/
@@ -1109,16 +1136,15 @@ static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
unsigned char *net_cat,
u32 net_cat_len)
{
- /* The constant '16' is not random, it is the maximum number of
- * high/low category range pairs as permitted by the CIPSO draft based
- * on a maximum IPv4 header length of 60 bytes - the BUG_ON() assertion
- * does a sanity check to make sure we don't overflow the array. */
int iter = -1;
- u16 array[16];
+ u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
u32 array_cnt = 0;
u32 cat_size = 0;
- BUG_ON(net_cat_len > 30);
+ /* make sure we don't overflow the 'array[]' variable */
+ if (net_cat_len >
+ (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
+ return -ENOSPC;
for (;;) {
iter = netlbl_secattr_catmap_walk(secattr->mls_cat, iter + 1);
@@ -1174,7 +1200,7 @@ static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
u16 cat_low;
u16 cat_high;
- for(net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
+ for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
cat_high = ntohs(*((__be16 *)&net_cat[net_iter]));
if ((net_iter + 4) <= net_cat_len)
cat_low = ntohs(*((__be16 *)&net_cat[net_iter + 2]));
@@ -1196,9 +1222,6 @@ static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
* Protocol Handling Functions
*/
-#define CIPSO_V4_OPT_LEN_MAX 40
-#define CIPSO_V4_HDR_LEN 6
-
/**
* cipso_v4_gentag_hdr - Generate a CIPSO option header
* @doi_def: the DOI definition
@@ -1676,7 +1699,7 @@ validate_return:
*/
void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
{
- if (skb->nh.iph->protocol == IPPROTO_ICMP || error != -EACCES)
+ if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
return;
if (gateway)