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[NetLabel]: rework the Netlink attribute handling (part 1)
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At the suggestion of Thomas Graf, rewrite NetLabel's use of Netlink attributes
to better follow the common Netlink attribute usage.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@pcmoore @davem330
pcmoore authored and davem330 committed Sep 25, 2006
1 parent 4fe5d5c commit fcd4828
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Showing 7 changed files with 76 additions and 604 deletions.
16 changes: 7 additions & 9 deletions include/net/cipso_ipv4.h
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Original file line number Diff line number Diff line change
Expand Up @@ -130,8 +130,9 @@ extern int cipso_v4_rbm_strictvalid;
int cipso_v4_doi_add(struct cipso_v4_doi *doi_def);
int cipso_v4_doi_remove(u32 doi, void (*callback) (struct rcu_head * head));
struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi);
struct sk_buff *cipso_v4_doi_dump_all(size_t headroom);
struct sk_buff *cipso_v4_doi_dump(u32 doi, size_t headroom);
int cipso_v4_doi_walk(u32 *skip_cnt,
int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
void *cb_arg);
int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def, const char *domain);
int cipso_v4_doi_domhsh_remove(struct cipso_v4_doi *doi_def,
const char *domain);
Expand All @@ -152,14 +153,11 @@ static inline struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
return NULL;
}

static inline struct sk_buff *cipso_v4_doi_dump_all(size_t headroom)
static inline int cipso_v4_doi_walk(u32 *skip_cnt,
int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
void *cb_arg)
{
return NULL;
}

static inline struct sk_buff *cipso_v4_doi_dump(u32 doi, size_t headroom)
{
return NULL;
return 0;
}

static inline int cipso_v4_doi_domhsh_add(struct cipso_v4_doi *doi_def,
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49 changes: 2 additions & 47 deletions include/net/netlabel.h
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Original file line number Diff line number Diff line change
Expand Up @@ -57,9 +57,8 @@
* The payload is dependent on the subsystem specified in the
* 'nlmsghdr->nlmsg_type' and should be defined below, supporting functions
* should be defined in the corresponding net/netlabel/netlabel_<subsys>.h|c
* file. All of the fields in the NetLabel payload are NETLINK attributes, the
* length of each field is the length of the NETLINK attribute payload, see
* include/net/netlink.h for more information on NETLINK attributes.
* file. All of the fields in the NetLabel payload are NETLINK attributes, see
* the include/net/netlink.h file for more information on NETLINK attributes.
*
*/

Expand All @@ -82,50 +81,6 @@
#define NETLBL_NLTYPE_UNLABELED 5
#define NETLBL_NLTYPE_UNLABELED_NAME "NLBL_UNLBL"

/* NetLabel return codes */
#define NETLBL_E_OK 0

/*
* Helper functions
*/

#define NETLBL_LEN_U8 nla_total_size(sizeof(u8))
#define NETLBL_LEN_U16 nla_total_size(sizeof(u16))
#define NETLBL_LEN_U32 nla_total_size(sizeof(u32))

/**
* netlbl_netlink_alloc_skb - Allocate a NETLINK message buffer
* @head: the amount of headroom in bytes
* @body: the desired size (minus headroom) in bytes
* @gfp_flags: the alloc flags to pass to alloc_skb()
*
* Description:
* Allocate a NETLINK message buffer based on the sizes given in @head and
* @body. If @head is greater than zero skb_reserve() is called to reserve
* @head bytes at the start of the buffer. Returns a valid sk_buff pointer on
* success, NULL on failure.
*
*/
static inline struct sk_buff *netlbl_netlink_alloc_skb(size_t head,
size_t body,
gfp_t gfp_flags)
{
struct sk_buff *skb;

skb = alloc_skb(NLMSG_ALIGN(head + body), gfp_flags);
if (skb == NULL)
return NULL;
if (head > 0) {
skb_reserve(skb, head);
if (skb_tailroom(skb) < body) {
kfree_skb(skb);
return NULL;
}
}

return skb;
}

/*
* NetLabel - Kernel API for accessing the network packet label mappings.
*
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203 changes: 24 additions & 179 deletions net/ipv4/cipso_ipv4.c
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Original file line number Diff line number Diff line change
Expand Up @@ -530,197 +530,42 @@ struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
}

/**
* cipso_v4_doi_dump_all - Dump all the CIPSO DOI definitions into a sk_buff
* @headroom: the amount of headroom to allocate for the sk_buff
* cipso_v4_doi_walk - Iterate through the DOI definitions
* @skip_cnt: skip past this number of DOI definitions, updated
* @callback: callback for each DOI definition
* @cb_arg: argument for the callback function
*
* Description:
* Dump a list of all the configured DOI values into a sk_buff. The returned
* sk_buff has room at the front of the sk_buff for @headroom bytes. See
* net/netlabel/netlabel_cipso_v4.h for the LISTALL message format. This
* function may fail if another process is changing the DOI list at the same
* time. Returns a pointer to a sk_buff on success, NULL on error.
* Iterate over the DOI definition list, skipping the first @skip_cnt entries.
* For each entry call @callback, if @callback returns a negative value stop
* 'walking' through the list and return. Updates the value in @skip_cnt upon
* return. Returns zero on success, negative values on failure.
*
*/
struct sk_buff *cipso_v4_doi_dump_all(size_t headroom)
int cipso_v4_doi_walk(u32 *skip_cnt,
int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
void *cb_arg)
{
struct sk_buff *skb = NULL;
struct cipso_v4_doi *iter;
int ret_val = -ENOENT;
u32 doi_cnt = 0;
ssize_t buf_len;

buf_len = NETLBL_LEN_U32;
rcu_read_lock();
list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
if (iter->valid) {
doi_cnt += 1;
buf_len += 2 * NETLBL_LEN_U32;
}

skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
if (skb == NULL)
goto doi_dump_all_failure;

if (nla_put_u32(skb, NLA_U32, doi_cnt) != 0)
goto doi_dump_all_failure;
buf_len -= NETLBL_LEN_U32;
list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
if (iter->valid) {
if (buf_len < 2 * NETLBL_LEN_U32)
goto doi_dump_all_failure;
if (nla_put_u32(skb, NLA_U32, iter->doi) != 0)
goto doi_dump_all_failure;
if (nla_put_u32(skb, NLA_U32, iter->type) != 0)
goto doi_dump_all_failure;
buf_len -= 2 * NETLBL_LEN_U32;
}
rcu_read_unlock();

return skb;

doi_dump_all_failure:
rcu_read_unlock();
kfree(skb);
return NULL;
}

/**
* cipso_v4_doi_dump - Dump a CIPSO DOI definition into a sk_buff
* @doi: the DOI value
* @headroom: the amount of headroom to allocate for the sk_buff
*
* Description:
* Lookup the DOI definition matching @doi and dump it's contents into a
* sk_buff. The returned sk_buff has room at the front of the sk_buff for
* @headroom bytes. See net/netlabel/netlabel_cipso_v4.h for the LIST message
* format. This function may fail if another process is changing the DOI list
* at the same time. Returns a pointer to a sk_buff on success, NULL on error.
*
*/
struct sk_buff *cipso_v4_doi_dump(u32 doi, size_t headroom)
{
struct sk_buff *skb = NULL;
struct cipso_v4_doi *iter;
u32 tag_cnt = 0;
u32 lvl_cnt = 0;
u32 cat_cnt = 0;
ssize_t buf_len;
ssize_t tmp;
struct cipso_v4_doi *iter_doi;

rcu_read_lock();
iter = cipso_v4_doi_getdef(doi);
if (iter == NULL)
goto doi_dump_failure;
buf_len = NETLBL_LEN_U32;
switch (iter->type) {
case CIPSO_V4_MAP_PASS:
buf_len += NETLBL_LEN_U32;
while(tag_cnt < CIPSO_V4_TAG_MAXCNT &&
iter->tags[tag_cnt] != CIPSO_V4_TAG_INVALID) {
tag_cnt += 1;
buf_len += NETLBL_LEN_U8;
}
break;
case CIPSO_V4_MAP_STD:
buf_len += 3 * NETLBL_LEN_U32;
while (tag_cnt < CIPSO_V4_TAG_MAXCNT &&
iter->tags[tag_cnt] != CIPSO_V4_TAG_INVALID) {
tag_cnt += 1;
buf_len += NETLBL_LEN_U8;
}
for (tmp = 0; tmp < iter->map.std->lvl.local_size; tmp++)
if (iter->map.std->lvl.local[tmp] !=
CIPSO_V4_INV_LVL) {
lvl_cnt += 1;
buf_len += NETLBL_LEN_U32 + NETLBL_LEN_U8;
list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
if (iter_doi->valid) {
if (doi_cnt++ < *skip_cnt)
continue;
ret_val = callback(iter_doi, cb_arg);
if (ret_val < 0) {
doi_cnt--;
goto doi_walk_return;
}
for (tmp = 0; tmp < iter->map.std->cat.local_size; tmp++)
if (iter->map.std->cat.local[tmp] !=
CIPSO_V4_INV_CAT) {
cat_cnt += 1;
buf_len += NETLBL_LEN_U32 + NETLBL_LEN_U16;
}
break;
}

skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
if (skb == NULL)
goto doi_dump_failure;

if (nla_put_u32(skb, NLA_U32, iter->type) != 0)
goto doi_dump_failure;
buf_len -= NETLBL_LEN_U32;
if (iter != cipso_v4_doi_getdef(doi))
goto doi_dump_failure;
switch (iter->type) {
case CIPSO_V4_MAP_PASS:
if (nla_put_u32(skb, NLA_U32, tag_cnt) != 0)
goto doi_dump_failure;
buf_len -= NETLBL_LEN_U32;
for (tmp = 0;
tmp < CIPSO_V4_TAG_MAXCNT &&
iter->tags[tmp] != CIPSO_V4_TAG_INVALID;
tmp++) {
if (buf_len < NETLBL_LEN_U8)
goto doi_dump_failure;
if (nla_put_u8(skb, NLA_U8, iter->tags[tmp]) != 0)
goto doi_dump_failure;
buf_len -= NETLBL_LEN_U8;
}
break;
case CIPSO_V4_MAP_STD:
if (nla_put_u32(skb, NLA_U32, tag_cnt) != 0)
goto doi_dump_failure;
if (nla_put_u32(skb, NLA_U32, lvl_cnt) != 0)
goto doi_dump_failure;
if (nla_put_u32(skb, NLA_U32, cat_cnt) != 0)
goto doi_dump_failure;
buf_len -= 3 * NETLBL_LEN_U32;
for (tmp = 0;
tmp < CIPSO_V4_TAG_MAXCNT &&
iter->tags[tmp] != CIPSO_V4_TAG_INVALID;
tmp++) {
if (buf_len < NETLBL_LEN_U8)
goto doi_dump_failure;
if (nla_put_u8(skb, NLA_U8, iter->tags[tmp]) != 0)
goto doi_dump_failure;
buf_len -= NETLBL_LEN_U8;
}
for (tmp = 0; tmp < iter->map.std->lvl.local_size; tmp++)
if (iter->map.std->lvl.local[tmp] !=
CIPSO_V4_INV_LVL) {
if (buf_len < NETLBL_LEN_U32 + NETLBL_LEN_U8)
goto doi_dump_failure;
if (nla_put_u32(skb, NLA_U32, tmp) != 0)
goto doi_dump_failure;
if (nla_put_u8(skb,
NLA_U8,
iter->map.std->lvl.local[tmp]) != 0)
goto doi_dump_failure;
buf_len -= NETLBL_LEN_U32 + NETLBL_LEN_U8;
}
for (tmp = 0; tmp < iter->map.std->cat.local_size; tmp++)
if (iter->map.std->cat.local[tmp] !=
CIPSO_V4_INV_CAT) {
if (buf_len < NETLBL_LEN_U32 + NETLBL_LEN_U16)
goto doi_dump_failure;
if (nla_put_u32(skb, NLA_U32, tmp) != 0)
goto doi_dump_failure;
if (nla_put_u16(skb,
NLA_U16,
iter->map.std->cat.local[tmp]) != 0)
goto doi_dump_failure;
buf_len -= NETLBL_LEN_U32 + NETLBL_LEN_U16;
}
break;
}
rcu_read_unlock();

return skb;

doi_dump_failure:
doi_walk_return:
rcu_read_unlock();
kfree(skb);
return NULL;
*skip_cnt = doi_cnt;
return ret_val;
}

/**
Expand Down
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