cipso: Add support for native local labeling and fixup mapping names

This patch accomplishes three minor tasks: add a new tag type for local
labeling, rename the CIPSO_V4_MAP_STD define to CIPSO_V4_MAP_TRANS and
replace some of the CIPSO "magic numbers" with constants from the header
file.  The first change allows CIPSO to support full LSM labels/contexts,
not just MLS attributes.  The second change brings the mapping names inline
with what userspace is using, compatibility is preserved since we don't
actually change the value.  The last change is to aid readability and help
prevent mistakes.
Signed-off-by: Paul Moore <paul.moore@hp.com>

include/net/cipso_ipv4.h

@@ -45,7 +45,7 @@
 /* known doi values */
 #define CIPSO_V4_DOI_UNKNOWN          0x00000000
 
-/* tag types */
+/* standard tag types */
 #define CIPSO_V4_TAG_INVALID          0
 #define CIPSO_V4_TAG_RBITMAP          1
 #define CIPSO_V4_TAG_ENUM             2
@@ -53,10 +53,14 @@
 #define CIPSO_V4_TAG_PBITMAP          6
 #define CIPSO_V4_TAG_FREEFORM         7
 
+/* non-standard tag types (tags > 127) */
+#define CIPSO_V4_TAG_LOCAL            128
+
 /* doi mapping types */
 #define CIPSO_V4_MAP_UNKNOWN          0
-#define CIPSO_V4_MAP_STD              1
+#define CIPSO_V4_MAP_TRANS            1
 #define CIPSO_V4_MAP_PASS             2
+#define CIPSO_V4_MAP_LOCAL            3
 
 /* limits */
 #define CIPSO_V4_MAX_REM_LVLS         255
@@ -215,7 +219,7 @@ int cipso_v4_skbuff_setattr(struct sk_buff *skb,
 int cipso_v4_skbuff_delattr(struct sk_buff *skb);
 int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
 			    struct netlbl_lsm_secattr *secattr);
-int cipso_v4_validate(unsigned char **option);
+int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option);
 #else
 static inline void cipso_v4_error(struct sk_buff *skb,
 				  int error,
@@ -259,7 +263,8 @@ static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
 	return -ENOSYS;
 }
 
-static inline int cipso_v4_validate(unsigned char **option)
+static inline int cipso_v4_validate(const struct sk_buff *skb,
+				    unsigned char **option)
 {
 	return -ENOSYS;
 }

net/ipv4/cipso_ipv4.c

@@ -109,6 +109,19 @@ int cipso_v4_rbm_strictvalid = 1;
  * be omitted. */
 #define CIPSO_V4_TAG_RNG_CAT_MAX      8
 
+/* Base length of the local tag (non-standard tag).
+ *  Tag definition (may change between kernel versions)
+ *
+ * 0          8          16         24         32
+ * +----------+----------+----------+----------+
+ * | 10000000 | 00000110 | 32-bit secid value  |
+ * +----------+----------+----------+----------+
+ * | in (host byte order)|
+ * +----------+----------+
+ *
+ */
+#define CIPSO_V4_TAG_LOC_BLEN         6
+
 /*
  * Helper Functions
  */
@@ -467,6 +480,10 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
 			if (doi_def->type != CIPSO_V4_MAP_PASS)
 				return -EINVAL;
 			break;
+		case CIPSO_V4_TAG_LOCAL:
+			if (doi_def->type != CIPSO_V4_MAP_LOCAL)
+				return -EINVAL;
+			break;
 		default:
 			return -EINVAL;
 		}
@@ -502,7 +519,7 @@ void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
 		return;
 
 	switch (doi_def->type) {
-	case CIPSO_V4_MAP_STD:
+	case CIPSO_V4_MAP_TRANS:
 		kfree(doi_def->map.std->lvl.cipso);
 		kfree(doi_def->map.std->lvl.local);
 		kfree(doi_def->map.std->cat.cipso);
@@ -673,7 +690,7 @@ static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
 	switch (doi_def->type) {
 	case CIPSO_V4_MAP_PASS:
 		return 0;
-	case CIPSO_V4_MAP_STD:
+	case CIPSO_V4_MAP_TRANS:
 		if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
 			return 0;
 		break;
@@ -702,7 +719,7 @@ static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
 	case CIPSO_V4_MAP_PASS:
 		*net_lvl = host_lvl;
 		return 0;
-	case CIPSO_V4_MAP_STD:
+	case CIPSO_V4_MAP_TRANS:
 		if (host_lvl < doi_def->map.std->lvl.local_size &&
 		    doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
 			*net_lvl = doi_def->map.std->lvl.local[host_lvl];
@@ -736,7 +753,7 @@ static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
 	case CIPSO_V4_MAP_PASS:
 		*host_lvl = net_lvl;
 		return 0;
-	case CIPSO_V4_MAP_STD:
+	case CIPSO_V4_MAP_TRANS:
 		map_tbl = doi_def->map.std;
 		if (net_lvl < map_tbl->lvl.cipso_size &&
 		    map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
@@ -773,7 +790,7 @@ static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
 	switch (doi_def->type) {
 	case CIPSO_V4_MAP_PASS:
 		return 0;
-	case CIPSO_V4_MAP_STD:
+	case CIPSO_V4_MAP_TRANS:
 		cipso_cat_size = doi_def->map.std->cat.cipso_size;
 		cipso_array = doi_def->map.std->cat.cipso;
 		for (;;) {
@@ -821,7 +838,7 @@ static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
 	u32 host_cat_size = 0;
 	u32 *host_cat_array = NULL;
 
-	if (doi_def->type == CIPSO_V4_MAP_STD) {
+	if (doi_def->type == CIPSO_V4_MAP_TRANS) {
 		host_cat_size = doi_def->map.std->cat.local_size;
 		host_cat_array = doi_def->map.std->cat.local;
 	}
@@ -836,7 +853,7 @@ static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
 		case CIPSO_V4_MAP_PASS:
 			net_spot = host_spot;
 			break;
-		case CIPSO_V4_MAP_STD:
+		case CIPSO_V4_MAP_TRANS:
 			if (host_spot >= host_cat_size)
 				return -EPERM;
 			net_spot = host_cat_array[host_spot];
@@ -882,7 +899,7 @@ static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
 	u32 net_cat_size = 0;
 	u32 *net_cat_array = NULL;
 
-	if (doi_def->type == CIPSO_V4_MAP_STD) {
+	if (doi_def->type == CIPSO_V4_MAP_TRANS) {
 		net_cat_size = doi_def->map.std->cat.cipso_size;
 		net_cat_array = doi_def->map.std->cat.cipso;
 	}
@@ -902,7 +919,7 @@ static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
 		case CIPSO_V4_MAP_PASS:
 			host_spot = net_spot;
 			break;
-		case CIPSO_V4_MAP_STD:
+		case CIPSO_V4_MAP_TRANS:
 			if (net_spot >= net_cat_size)
 				return -EPERM;
 			host_spot = net_cat_array[net_spot];
@@ -1238,7 +1255,7 @@ static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
 	} else
 		tag_len = 4;
 
-	buffer[0] = 0x01;
+	buffer[0] = CIPSO_V4_TAG_RBITMAP;
 	buffer[1] = tag_len;
 	buffer[3] = level;
 
@@ -1334,7 +1351,7 @@ static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
 	} else
 		tag_len = 4;
 
-	buffer[0] = 0x02;
+	buffer[0] = CIPSO_V4_TAG_ENUM;
 	buffer[1] = tag_len;
 	buffer[3] = level;
 
@@ -1430,7 +1447,7 @@ static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
 	} else
 		tag_len = 4;
 
-	buffer[0] = 0x05;
+	buffer[0] = CIPSO_V4_TAG_RANGE;
 	buffer[1] = tag_len;
 	buffer[3] = level;
 
@@ -1483,6 +1500,54 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
 	return 0;
 }
 
+/**
+ * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
+ * @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 local tag.  Returns the size of the tag
+ * on success, negative values on failure.
+ *
+ */
+static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
+			       const struct netlbl_lsm_secattr *secattr,
+			       unsigned char *buffer,
+			       u32 buffer_len)
+{
+	if (!(secattr->flags & NETLBL_SECATTR_SECID))
+		return -EPERM;
+
+	buffer[0] = CIPSO_V4_TAG_LOCAL;
+	buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
+	*(u32 *)&buffer[2] = secattr->attr.secid;
+
+	return CIPSO_V4_TAG_LOC_BLEN;
+}
+
+/**
+ * cipso_v4_parsetag_loc - Parse a CIPSO local tag
+ * @doi_def: the DOI definition
+ * @tag: the CIPSO tag
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Parse a CIPSO local tag and return the security attributes in @secattr.
+ * Return zero on success, negatives values on failure.
+ *
+ */
+static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
+				 const unsigned char *tag,
+				 struct netlbl_lsm_secattr *secattr)
+{
+	secattr->attr.secid = *(u32 *)&tag[2];
+	secattr->flags |= NETLBL_SECATTR_SECID;
+
+	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
@@ -1502,7 +1567,7 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
  *   that is unrecognized."
  *
  */
-int cipso_v4_validate(unsigned char **option)
+int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
 {
 	unsigned char *opt = *option;
 	unsigned char *tag;
@@ -1527,7 +1592,7 @@ int cipso_v4_validate(unsigned char **option)
 		goto validate_return_locked;
 	}
 
-	opt_iter = 6;
+	opt_iter = CIPSO_V4_HDR_LEN;
 	tag = opt + opt_iter;
 	while (opt_iter < opt_len) {
 		for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
@@ -1545,7 +1610,7 @@ int cipso_v4_validate(unsigned char **option)
 
 		switch (tag[0]) {
 		case CIPSO_V4_TAG_RBITMAP:
-			if (tag_len < 4) {
+			if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
 				err_offset = opt_iter + 1;
 				goto validate_return_locked;
 			}
@@ -1563,7 +1628,7 @@ int cipso_v4_validate(unsigned char **option)
 					err_offset = opt_iter + 3;
 					goto validate_return_locked;
 				}
-				if (tag_len > 4 &&
+				if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
 				    cipso_v4_map_cat_rbm_valid(doi_def,
 							    &tag[4],
 							    tag_len - 4) < 0) {
@@ -1573,7 +1638,7 @@ int cipso_v4_validate(unsigned char **option)
 			}
 			break;
 		case CIPSO_V4_TAG_ENUM:
-			if (tag_len < 4) {
+			if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
 				err_offset = opt_iter + 1;
 				goto validate_return_locked;
 			}
@@ -1583,7 +1648,7 @@ int cipso_v4_validate(unsigned char **option)
 				err_offset = opt_iter + 3;
 				goto validate_return_locked;
 			}
-			if (tag_len > 4 &&
+			if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
 			    cipso_v4_map_cat_enum_valid(doi_def,
 							&tag[4],
 							tag_len - 4) < 0) {
@@ -1592,7 +1657,7 @@ int cipso_v4_validate(unsigned char **option)
 			}
 			break;
 		case CIPSO_V4_TAG_RANGE:
-			if (tag_len < 4) {
+			if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
 				err_offset = opt_iter + 1;
 				goto validate_return_locked;
 			}
@@ -1602,7 +1667,7 @@ int cipso_v4_validate(unsigned char **option)
 				err_offset = opt_iter + 3;
 				goto validate_return_locked;
 			}
-			if (tag_len > 4 &&
+			if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
 			    cipso_v4_map_cat_rng_valid(doi_def,
 						       &tag[4],
 						       tag_len - 4) < 0) {
@@ -1610,6 +1675,19 @@ int cipso_v4_validate(unsigned char **option)
 				goto validate_return_locked;
 			}
 			break;
+		case CIPSO_V4_TAG_LOCAL:
+			/* This is a non-standard tag that we only allow for
+			 * local connections, so if the incoming interface is
+			 * not the loopback device drop the packet. */
+			if (!(skb->dev->flags & IFF_LOOPBACK)) {
+				err_offset = opt_iter;
+				goto validate_return_locked;
+			}
+			if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
+				err_offset = opt_iter + 1;
+				goto validate_return_locked;
+			}
+			break;
 		default:
 			err_offset = opt_iter;
 			goto validate_return_locked;
@@ -1712,6 +1790,12 @@ static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
 						   &buf[CIPSO_V4_HDR_LEN],
 						   buf_len - CIPSO_V4_HDR_LEN);
 			break;
+		case CIPSO_V4_TAG_LOCAL:
+			ret_val = cipso_v4_gentag_loc(doi_def,
+						   secattr,
+						   &buf[CIPSO_V4_HDR_LEN],
+						   buf_len - CIPSO_V4_HDR_LEN);
+			break;
 		default:
 			return -EPERM;
 		}
@@ -1921,6 +2005,9 @@ static int cipso_v4_getattr(const unsigned char *cipso,
 	case CIPSO_V4_TAG_RANGE:
 		ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
 		break;
+	case CIPSO_V4_TAG_LOCAL:
+		ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
+		break;
 	}
 	if (ret_val == 0)
 		secattr->type = NETLBL_NLTYPE_CIPSOV4;

net/ipv4/ip_options.c

@@ -438,7 +438,7 @@ int ip_options_compile(struct net *net,
 				goto error;
 			}
 			opt->cipso = optptr - iph;
-			if (cipso_v4_validate(&optptr)) {
+			if (cipso_v4_validate(skb, &optptr)) {
 				pp_ptr = optptr;
 				goto error;
 			}

net/netlabel/netlabel_cipso_v4.c

@@ -132,9 +132,9 @@ static int netlbl_cipsov4_add_common(struct genl_info *info,
  * @info: the Generic NETLINK info block
  *
  * Description:
- * Create a new CIPSO_V4_MAP_STD DOI definition based on the given ADD message
- * and add it to the CIPSO V4 engine.  Return zero on success and non-zero on
- * error.
+ * Create a new CIPSO_V4_MAP_TRANS DOI definition based on the given ADD
+ * message and add it to the CIPSO V4 engine.  Return zero on success and
+ * non-zero on error.
  *
  */
 static int netlbl_cipsov4_add_std(struct genl_info *info)
@@ -164,7 +164,7 @@ static int netlbl_cipsov4_add_std(struct genl_info *info)
 		ret_val = -ENOMEM;
 		goto add_std_failure;
 	}
-	doi_def->type = CIPSO_V4_MAP_STD;
+	doi_def->type = CIPSO_V4_MAP_TRANS;
 
 	ret_val = netlbl_cipsov4_add_common(info, doi_def);
 	if (ret_val != 0)
@@ -393,8 +393,8 @@ static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)
 
 	type = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE]);
 	switch (type) {
-	case CIPSO_V4_MAP_STD:
-		type_str = "std";
+	case CIPSO_V4_MAP_TRANS:
+		type_str = "trans";
 		ret_val = netlbl_cipsov4_add_std(info);
 		break;
 	case CIPSO_V4_MAP_PASS:
@@ -497,7 +497,7 @@ static int netlbl_cipsov4_list(struct sk_buff *skb, struct genl_info *info)
 	nla_nest_end(ans_skb, nla_a);
 
 	switch (doi_def->type) {
-	case CIPSO_V4_MAP_STD:
+	case CIPSO_V4_MAP_TRANS:
 		nla_a = nla_nest_start(ans_skb, NLBL_CIPSOV4_A_MLSLVLLST);
 		if (nla_a == NULL) {
 			ret_val = -ENOMEM;

net/netlabel/netlabel_cipso_v4.h

@@ -45,7 +45,7 @@
  *     NLBL_CIPSOV4_A_MTYPE
  *     NLBL_CIPSOV4_A_TAGLST
  *
- *   If using CIPSO_V4_MAP_STD the following attributes are required:
+ *   If using CIPSO_V4_MAP_TRANS the following attributes are required:
  *
  *     NLBL_CIPSOV4_A_MLSLVLLST
  *     NLBL_CIPSOV4_A_MLSCATLST
@@ -76,7 +76,7 @@
  *     NLBL_CIPSOV4_A_MTYPE
  *     NLBL_CIPSOV4_A_TAGLST
  *
- *   If using CIPSO_V4_MAP_STD the following attributes are required:
+ *   If using CIPSO_V4_MAP_TRANS the following attributes are required:
  *
  *     NLBL_CIPSOV4_A_MLSLVLLST
  *     NLBL_CIPSOV4_A_MLSCATLST

net/netlabel/netlabel_kapi.c

@@ -157,8 +157,8 @@ int netlbl_cfg_cipsov4_add_map(struct cipso_v4_doi *doi_def,
 					      audit_info);
 	if (audit_buf != NULL) {
 		switch (doi_type) {
-		case CIPSO_V4_MAP_STD:
-			type_str = "std";
+		case CIPSO_V4_MAP_TRANS:
+			type_str = "trans";
 			break;
 		case CIPSO_V4_MAP_PASS:
 			type_str = "pass";