diff options
Diffstat (limited to 'net/ipv4/cipso_ipv4.c')
| -rw-r--r-- | net/ipv4/cipso_ipv4.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 11a3404d65a..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); @@ -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 |