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>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 23768b9..490e035c 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -109,6 +109,19 @@
* 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
} else
tag_len = 4;
- buffer[0] = 0x01;
+ buffer[0] = CIPSO_V4_TAG_RBITMAP;
buffer[1] = tag_len;
buffer[3] = level;
@@ -1334,7 +1351,7 @@
} else
tag_len = 4;
- buffer[0] = 0x02;
+ buffer[0] = CIPSO_V4_TAG_ENUM;
buffer[1] = tag_len;
buffer[3] = level;
@@ -1430,7 +1447,7 @@
} else
tag_len = 4;
- buffer[0] = 0x05;
+ buffer[0] = CIPSO_V4_TAG_RANGE;
buffer[1] = tag_len;
buffer[3] = level;
@@ -1484,6 +1501,54 @@
}
/**
+ * 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 @@
* 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 @@
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 @@
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 @@
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 @@
}
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 @@
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 @@
}
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 @@
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 @@
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 @@
&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 @@
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;