From 654bbc2a2b87185630d05b79cc0db0e9364bb7e0 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Wed, 29 Nov 2006 13:18:19 -0500 Subject: [PATCH] NetLabel: add the enumerated tag to the CIPSOv4 protocol Add support for the enumerated tag (tag type #2) to the CIPSOv4 protocol. The enumerated tag allows for 15 categories to be specified in a CIPSO option, where each category is an unsigned 16 bit field with a maximum value of 65534. See Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt for more details. Signed-off-by: Paul Moore Signed-off-by: James Morris --- net/ipv4/cipso_ipv4.c | 233 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 233 insertions(+) diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c index 08144f8fc91..70858dccaca 100644 --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -459,6 +459,10 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) if (iter == 0) return -EINVAL; break; + case CIPSO_V4_TAG_ENUM: + if (doi_def->type != CIPSO_V4_MAP_PASS) + return -EINVAL; + break; default: return -EINVAL; } @@ -940,6 +944,107 @@ static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def, return -EINVAL; } +/** + * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid + * @doi_def: the DOI definition + * @enumcat: category list + * @enumcat_len: length of the category list in bytes + * + * Description: + * Checks the given categories against the given DOI definition and returns a + * negative value if any of the categories do not have a valid mapping and a + * zero value if all of the categories are valid. + * + */ +static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def, + const unsigned char *enumcat, + u32 enumcat_len) +{ + u16 cat; + int cat_prev = -1; + u32 iter; + + if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01) + return -EFAULT; + + for (iter = 0; iter < enumcat_len; iter += 2) { + cat = ntohs(*((__be16 *)&enumcat[iter])); + if (cat <= cat_prev) + return -EFAULT; + cat_prev = cat; + } + + return 0; +} + +/** + * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network + * @doi_def: the DOI definition + * @secattr: the security attributes + * @net_cat: the zero'd out category list in network/CIPSO format + * @net_cat_len: the length of the CIPSO category list in bytes + * + * Description: + * Perform a label mapping to translate a local MLS category bitmap to the + * correct CIPSO category list using the given DOI definition. Returns the + * size in bytes of the network category bitmap on success, negative values + * otherwise. + * + */ +static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *net_cat, + u32 net_cat_len) +{ + int cat = -1; + u32 cat_iter = 0; + + for (;;) { + cat = netlbl_secattr_catmap_walk(secattr->mls_cat, cat + 1); + if (cat < 0) + break; + if ((cat_iter + 2) > net_cat_len) + return -ENOSPC; + + *((__be16 *)&net_cat[cat_iter]) = htons(cat); + cat_iter += 2; + } + + return cat_iter; +} + +/** + * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host + * @doi_def: the DOI definition + * @net_cat: the category list in network/CIPSO format + * @net_cat_len: the length of the CIPSO bitmap in bytes + * @secattr: the security attributes + * + * Description: + * Perform a label mapping to translate a CIPSO category list to the correct + * local MLS category bitmap using the given DOI definition. Returns zero on + * success, negative values on failure. + * + */ +static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def, + const unsigned char *net_cat, + u32 net_cat_len, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u32 iter; + + for (iter = 0; iter < net_cat_len; iter += 2) { + ret_val = netlbl_secattr_catmap_setbit(secattr->mls_cat, + ntohs(*((__be16 *)&net_cat[iter])), + GFP_ATOMIC); + if (ret_val != 0) + return ret_val; + } + + return 0; +} + /* * Protocol Handling Functions */ @@ -1067,6 +1172,99 @@ static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def, return 0; } +/** + * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2) + * @doi_def: the DOI definition + * @secattr: the security attributes + * @buffer: the option buffer + * @buffer_len: length of buffer in bytes + * + * Description: + * Generate a CIPSO option using the enumerated tag, tag type #2. Returns the + * size of the tag on success, negative values on failure. + * + */ +static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def, + const struct netlbl_lsm_secattr *secattr, + unsigned char *buffer, + u32 buffer_len) +{ + int ret_val; + u32 tag_len; + u32 level; + + if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL)) + return -EPERM; + + ret_val = cipso_v4_map_lvl_hton(doi_def, secattr->mls_lvl, &level); + if (ret_val != 0) + return ret_val; + + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + ret_val = cipso_v4_map_cat_enum_hton(doi_def, + secattr, + &buffer[4], + buffer_len - 4); + if (ret_val < 0) + return ret_val; + + tag_len = 4 + ret_val; + } else + tag_len = 4; + + buffer[0] = 0x02; + buffer[1] = tag_len; + buffer[3] = level; + + return tag_len; +} + +/** + * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag + * @doi_def: the DOI definition + * @tag: the CIPSO tag + * @secattr: the security attributes + * + * Description: + * Parse a CIPSO enumerated tag (tag type #2) and return the security + * attributes in @secattr. Return zero on success, negatives values on + * failure. + * + */ +static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def, + const unsigned char *tag, + struct netlbl_lsm_secattr *secattr) +{ + int ret_val; + u8 tag_len = tag[1]; + u32 level; + + ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level); + if (ret_val != 0) + return ret_val; + secattr->mls_lvl = level; + secattr->flags |= NETLBL_SECATTR_MLS_LVL; + + if (tag_len > 4) { + secattr->mls_cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); + if (secattr->mls_cat == NULL) + return -ENOMEM; + + ret_val = cipso_v4_map_cat_enum_ntoh(doi_def, + &tag[4], + tag_len - 4, + secattr); + if (ret_val != 0) { + netlbl_secattr_catmap_free(secattr->mls_cat); + return ret_val; + } + + secattr->flags |= NETLBL_SECATTR_MLS_CAT; + } + + return 0; +} + /** * cipso_v4_validate - Validate a CIPSO option * @option: the start of the option, on error it is set to point to the error @@ -1156,6 +1354,25 @@ int cipso_v4_validate(unsigned char **option) } } break; + case CIPSO_V4_TAG_ENUM: + if (tag_len < 4) { + err_offset = opt_iter + 1; + goto validate_return_locked; + } + + if (cipso_v4_map_lvl_valid(doi_def, + tag[3]) < 0) { + err_offset = opt_iter + 3; + goto validate_return_locked; + } + if (tag_len > 4 && + cipso_v4_map_cat_enum_valid(doi_def, + &tag[4], + tag_len - 4) < 0) { + err_offset = opt_iter + 4; + goto validate_return_locked; + } + break; default: err_offset = opt_iter; goto validate_return_locked; @@ -1269,6 +1486,12 @@ int cipso_v4_socket_setattr(const struct socket *sock, &buf[CIPSO_V4_HDR_LEN], buf_len - CIPSO_V4_HDR_LEN); break; + case CIPSO_V4_TAG_ENUM: + ret_val = cipso_v4_gentag_enum(doi_def, + secattr, + &buf[CIPSO_V4_HDR_LEN], + buf_len - CIPSO_V4_HDR_LEN); + break; default: ret_val = -EPERM; goto socket_setattr_failure; @@ -1365,6 +1588,11 @@ int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr) &cipso_ptr[6], secattr); break; + case CIPSO_V4_TAG_ENUM: + ret_val = cipso_v4_parsetag_enum(doi_def, + &cipso_ptr[6], + secattr); + break; } rcu_read_unlock(); @@ -1431,6 +1659,11 @@ int cipso_v4_skbuff_getattr(const struct sk_buff *skb, &cipso_ptr[6], secattr); break; + case CIPSO_V4_TAG_ENUM: + ret_val = cipso_v4_parsetag_enum(doi_def, + &cipso_ptr[6], + secattr); + break; } skbuff_getattr_return: -- 2.41.1