linux_dsm_epyc7002/net/netlabel/netlabel_mgmt.c

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/*
* NetLabel Management Support
*
* This file defines the management functions for the NetLabel system. The
* NetLabel system manages static and dynamic label mappings for network
* protocols such as CIPSO and RIPSO.
*
* Author: Paul Moore <paul@paul-moore.com>
*
*/
/*
* (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/in6.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 15:04:11 +07:00
#include <linux/slab.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/netlabel.h>
#include <net/cipso_ipv4.h>
#include <linux/atomic.h>
#include "netlabel_domainhash.h"
#include "netlabel_user.h"
#include "netlabel_mgmt.h"
/* NetLabel configured protocol counter */
atomic_t netlabel_mgmt_protocount = ATOMIC_INIT(0);
/* Argument struct for netlbl_domhsh_walk() */
struct netlbl_domhsh_walk_arg {
struct netlink_callback *nl_cb;
struct sk_buff *skb;
u32 seq;
};
/* NetLabel Generic NETLINK CIPSOv4 family */
static struct genl_family netlbl_mgmt_gnl_family = {
.id = GENL_ID_GENERATE,
.hdrsize = 0,
.name = NETLBL_NLTYPE_MGMT_NAME,
.version = NETLBL_PROTO_VERSION,
.maxattr = NLBL_MGMT_A_MAX,
};
/* NetLabel Netlink attribute policy */
static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
[NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
[NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
[NLBL_MGMT_A_FAMILY] = { .type = NLA_U16 },
};
/*
* Helper Functions
*/
/**
* netlbl_mgmt_add - Handle an ADD message
* @info: the Generic NETLINK info block
* @audit_info: NetLabel audit information
*
* Description:
* Helper function for the ADD and ADDDEF messages to add the domain mappings
* from the message to the hash table. See netlabel.h for a description of the
* message format. Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_add_common(struct genl_info *info,
struct netlbl_audit *audit_info)
{
int ret_val = -EINVAL;
struct netlbl_domaddr_map *addrmap = NULL;
struct cipso_v4_doi *cipsov4 = NULL;
u32 tmp_val;
struct netlbl_dom_map *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->def.type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
if (info->attrs[NLBL_MGMT_A_DOMAIN]) {
size_t tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
entry->domain = kmalloc(tmp_size, GFP_KERNEL);
if (entry->domain == NULL) {
ret_val = -ENOMEM;
goto add_free_entry;
}
nla_strlcpy(entry->domain,
info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
}
/* NOTE: internally we allow/use a entry->def.type value of
* NETLBL_NLTYPE_ADDRSELECT but we don't currently allow users
* to pass that as a protocol value because we need to know the
* "real" protocol */
switch (entry->def.type) {
case NETLBL_NLTYPE_UNLABELED:
if (info->attrs[NLBL_MGMT_A_FAMILY])
entry->family =
nla_get_u16(info->attrs[NLBL_MGMT_A_FAMILY]);
else
entry->family = AF_UNSPEC;
break;
case NETLBL_NLTYPE_CIPSOV4:
if (!info->attrs[NLBL_MGMT_A_CV4DOI])
goto add_free_domain;
tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
cipsov4 = cipso_v4_doi_getdef(tmp_val);
if (cipsov4 == NULL)
goto add_free_domain;
entry->family = AF_INET;
entry->def.cipso = cipsov4;
break;
default:
goto add_free_domain;
}
if ((entry->family == AF_INET && info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
(entry->family == AF_INET6 && info->attrs[NLBL_MGMT_A_IPV4ADDR]))
goto add_doi_put_def;
if (info->attrs[NLBL_MGMT_A_IPV4ADDR]) {
struct in_addr *addr;
struct in_addr *mask;
struct netlbl_domaddr4_map *map;
addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
if (addrmap == NULL) {
ret_val = -ENOMEM;
goto add_doi_put_def;
}
INIT_LIST_HEAD(&addrmap->list4);
INIT_LIST_HEAD(&addrmap->list6);
if (nla_len(info->attrs[NLBL_MGMT_A_IPV4ADDR]) !=
sizeof(struct in_addr)) {
ret_val = -EINVAL;
goto add_free_addrmap;
}
if (nla_len(info->attrs[NLBL_MGMT_A_IPV4MASK]) !=
sizeof(struct in_addr)) {
ret_val = -EINVAL;
goto add_free_addrmap;
}
addr = nla_data(info->attrs[NLBL_MGMT_A_IPV4ADDR]);
mask = nla_data(info->attrs[NLBL_MGMT_A_IPV4MASK]);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (map == NULL) {
ret_val = -ENOMEM;
goto add_free_addrmap;
}
map->list.addr = addr->s_addr & mask->s_addr;
map->list.mask = mask->s_addr;
map->list.valid = 1;
map->def.type = entry->def.type;
if (cipsov4)
map->def.cipso = cipsov4;
ret_val = netlbl_af4list_add(&map->list, &addrmap->list4);
if (ret_val != 0) {
kfree(map);
goto add_free_addrmap;
}
entry->family = AF_INET;
entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
entry->def.addrsel = addrmap;
#if IS_ENABLED(CONFIG_IPV6)
} else if (info->attrs[NLBL_MGMT_A_IPV6ADDR]) {
struct in6_addr *addr;
struct in6_addr *mask;
struct netlbl_domaddr6_map *map;
addrmap = kzalloc(sizeof(*addrmap), GFP_KERNEL);
if (addrmap == NULL) {
ret_val = -ENOMEM;
goto add_doi_put_def;
}
INIT_LIST_HEAD(&addrmap->list4);
INIT_LIST_HEAD(&addrmap->list6);
if (nla_len(info->attrs[NLBL_MGMT_A_IPV6ADDR]) !=
sizeof(struct in6_addr)) {
ret_val = -EINVAL;
goto add_free_addrmap;
}
if (nla_len(info->attrs[NLBL_MGMT_A_IPV6MASK]) !=
sizeof(struct in6_addr)) {
ret_val = -EINVAL;
goto add_free_addrmap;
}
addr = nla_data(info->attrs[NLBL_MGMT_A_IPV6ADDR]);
mask = nla_data(info->attrs[NLBL_MGMT_A_IPV6MASK]);
map = kzalloc(sizeof(*map), GFP_KERNEL);
if (map == NULL) {
ret_val = -ENOMEM;
goto add_free_addrmap;
}
map->list.addr = *addr;
map->list.addr.s6_addr32[0] &= mask->s6_addr32[0];
map->list.addr.s6_addr32[1] &= mask->s6_addr32[1];
map->list.addr.s6_addr32[2] &= mask->s6_addr32[2];
map->list.addr.s6_addr32[3] &= mask->s6_addr32[3];
map->list.mask = *mask;
map->list.valid = 1;
map->def.type = entry->def.type;
ret_val = netlbl_af6list_add(&map->list, &addrmap->list6);
if (ret_val != 0) {
kfree(map);
goto add_free_addrmap;
}
entry->family = AF_INET6;
entry->def.type = NETLBL_NLTYPE_ADDRSELECT;
entry->def.addrsel = addrmap;
#endif /* IPv6 */
}
ret_val = netlbl_domhsh_add(entry, audit_info);
if (ret_val != 0)
goto add_free_addrmap;
return 0;
add_free_addrmap:
kfree(addrmap);
add_doi_put_def:
cipso_v4_doi_putdef(cipsov4);
add_free_domain:
kfree(entry->domain);
add_free_entry:
kfree(entry);
return ret_val;
}
/**
* netlbl_mgmt_listentry - List a NetLabel/LSM domain map entry
* @skb: the NETLINK buffer
* @entry: the map entry
*
* Description:
* This function is a helper function used by the LISTALL and LISTDEF command
* handlers. The caller is responsible for ensuring that the RCU read lock
* is held. Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_listentry(struct sk_buff *skb,
struct netlbl_dom_map *entry)
{
int ret_val = 0;
struct nlattr *nla_a;
struct nlattr *nla_b;
struct netlbl_af4list *iter4;
#if IS_ENABLED(CONFIG_IPV6)
struct netlbl_af6list *iter6;
#endif
if (entry->domain != NULL) {
ret_val = nla_put_string(skb,
NLBL_MGMT_A_DOMAIN, entry->domain);
if (ret_val != 0)
return ret_val;
}
ret_val = nla_put_u16(skb, NLBL_MGMT_A_FAMILY, entry->family);
if (ret_val != 0)
return ret_val;
switch (entry->def.type) {
case NETLBL_NLTYPE_ADDRSELECT:
nla_a = nla_nest_start(skb, NLBL_MGMT_A_SELECTORLIST);
if (nla_a == NULL)
return -ENOMEM;
netlbl_af4list_foreach_rcu(iter4, &entry->def.addrsel->list4) {
struct netlbl_domaddr4_map *map4;
struct in_addr addr_struct;
nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
if (nla_b == NULL)
return -ENOMEM;
addr_struct.s_addr = iter4->addr;
ret_val = nla_put_in_addr(skb, NLBL_MGMT_A_IPV4ADDR,
addr_struct.s_addr);
if (ret_val != 0)
return ret_val;
addr_struct.s_addr = iter4->mask;
ret_val = nla_put_in_addr(skb, NLBL_MGMT_A_IPV4MASK,
addr_struct.s_addr);
if (ret_val != 0)
return ret_val;
map4 = netlbl_domhsh_addr4_entry(iter4);
ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
map4->def.type);
if (ret_val != 0)
return ret_val;
switch (map4->def.type) {
case NETLBL_NLTYPE_CIPSOV4:
ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
map4->def.cipso->doi);
if (ret_val != 0)
return ret_val;
break;
}
nla_nest_end(skb, nla_b);
}
#if IS_ENABLED(CONFIG_IPV6)
netlbl_af6list_foreach_rcu(iter6, &entry->def.addrsel->list6) {
struct netlbl_domaddr6_map *map6;
nla_b = nla_nest_start(skb, NLBL_MGMT_A_ADDRSELECTOR);
if (nla_b == NULL)
return -ENOMEM;
ret_val = nla_put_in6_addr(skb, NLBL_MGMT_A_IPV6ADDR,
&iter6->addr);
if (ret_val != 0)
return ret_val;
ret_val = nla_put_in6_addr(skb, NLBL_MGMT_A_IPV6MASK,
&iter6->mask);
if (ret_val != 0)
return ret_val;
map6 = netlbl_domhsh_addr6_entry(iter6);
ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL,
map6->def.type);
if (ret_val != 0)
return ret_val;
nla_nest_end(skb, nla_b);
}
#endif /* IPv6 */
nla_nest_end(skb, nla_a);
break;
case NETLBL_NLTYPE_UNLABELED:
ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
break;
case NETLBL_NLTYPE_CIPSOV4:
ret_val = nla_put_u32(skb,NLBL_MGMT_A_PROTOCOL,entry->def.type);
if (ret_val != 0)
return ret_val;
ret_val = nla_put_u32(skb, NLBL_MGMT_A_CV4DOI,
entry->def.cipso->doi);
break;
}
return ret_val;
}
/*
* NetLabel Command Handlers
*/
/**
* netlbl_mgmt_add - Handle an ADD message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated ADD message and add the domains from the message
* to the hash table. See netlabel.h for a description of the message format.
* Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
{
struct netlbl_audit audit_info;
if ((!info->attrs[NLBL_MGMT_A_DOMAIN]) ||
(!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
(info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
(info->attrs[NLBL_MGMT_A_IPV4MASK] &&
info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
(info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
(info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
return -EINVAL;
netlbl_netlink_auditinfo(skb, &audit_info);
return netlbl_mgmt_add_common(info, &audit_info);
}
/**
* netlbl_mgmt_remove - Handle a REMOVE message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated REMOVE message and remove the specified domain
* mappings. Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
{
char *domain;
struct netlbl_audit audit_info;
if (!info->attrs[NLBL_MGMT_A_DOMAIN])
return -EINVAL;
netlbl_netlink_auditinfo(skb, &audit_info);
domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
return netlbl_domhsh_remove(domain, AF_UNSPEC, &audit_info);
}
/**
* netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
* @entry: the domain mapping hash table entry
* @arg: the netlbl_domhsh_walk_arg structure
*
* Description:
* This function is designed to be used as a callback to the
* netlbl_domhsh_walk() function for use in generating a response for a LISTALL
* message. Returns the size of the message on success, negative values on
* failure.
*
*/
static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
{
int ret_val = -ENOMEM;
struct netlbl_domhsh_walk_arg *cb_arg = arg;
void *data;
data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
cb_arg->seq, &netlbl_mgmt_gnl_family,
NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
if (data == NULL)
goto listall_cb_failure;
ret_val = netlbl_mgmt_listentry(cb_arg->skb, entry);
if (ret_val != 0)
goto listall_cb_failure;
cb_arg->seq++;
netlink: make nlmsg_end() and genlmsg_end() void Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-17 04:09:00 +07:00
genlmsg_end(cb_arg->skb, data);
return 0;
listall_cb_failure:
genlmsg_cancel(cb_arg->skb, data);
return ret_val;
}
/**
* netlbl_mgmt_listall - Handle a LISTALL message
* @skb: the NETLINK buffer
* @cb: the NETLINK callback
*
* Description:
* Process a user generated LISTALL message and dumps the domain hash table in
* a form suitable for use in a kernel generated LISTALL message. Returns zero
* on success, negative values on failure.
*
*/
static int netlbl_mgmt_listall(struct sk_buff *skb,
struct netlink_callback *cb)
{
struct netlbl_domhsh_walk_arg cb_arg;
u32 skip_bkt = cb->args[0];
u32 skip_chain = cb->args[1];
cb_arg.nl_cb = cb;
cb_arg.skb = skb;
cb_arg.seq = cb->nlh->nlmsg_seq;
netlbl_domhsh_walk(&skip_bkt,
&skip_chain,
netlbl_mgmt_listall_cb,
&cb_arg);
cb->args[0] = skip_bkt;
cb->args[1] = skip_chain;
return skb->len;
}
/**
* netlbl_mgmt_adddef - Handle an ADDDEF message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated ADDDEF message and respond accordingly. Returns
* zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
{
struct netlbl_audit audit_info;
if ((!info->attrs[NLBL_MGMT_A_PROTOCOL]) ||
(info->attrs[NLBL_MGMT_A_IPV4ADDR] &&
info->attrs[NLBL_MGMT_A_IPV6ADDR]) ||
(info->attrs[NLBL_MGMT_A_IPV4MASK] &&
info->attrs[NLBL_MGMT_A_IPV6MASK]) ||
((info->attrs[NLBL_MGMT_A_IPV4ADDR] != NULL) ^
(info->attrs[NLBL_MGMT_A_IPV4MASK] != NULL)) ||
((info->attrs[NLBL_MGMT_A_IPV6ADDR] != NULL) ^
(info->attrs[NLBL_MGMT_A_IPV6MASK] != NULL)))
return -EINVAL;
netlbl_netlink_auditinfo(skb, &audit_info);
return netlbl_mgmt_add_common(info, &audit_info);
}
/**
* netlbl_mgmt_removedef - Handle a REMOVEDEF message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated REMOVEDEF message and remove the default domain
* mapping. Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
{
struct netlbl_audit audit_info;
netlbl_netlink_auditinfo(skb, &audit_info);
return netlbl_domhsh_remove_default(AF_UNSPEC, &audit_info);
}
/**
* netlbl_mgmt_listdef - Handle a LISTDEF message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated LISTDEF message and dumps the default domain
* mapping in a form suitable for use in a kernel generated LISTDEF message.
* Returns zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
{
int ret_val = -ENOMEM;
struct sk_buff *ans_skb = NULL;
void *data;
struct netlbl_dom_map *entry;
u16 family;
if (info->attrs[NLBL_MGMT_A_FAMILY])
family = nla_get_u16(info->attrs[NLBL_MGMT_A_FAMILY]);
else
family = AF_INET;
ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (ans_skb == NULL)
return -ENOMEM;
data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
0, NLBL_MGMT_C_LISTDEF);
if (data == NULL)
goto listdef_failure;
rcu_read_lock();
entry = netlbl_domhsh_getentry(NULL, family);
if (entry == NULL) {
ret_val = -ENOENT;
goto listdef_failure_lock;
}
ret_val = netlbl_mgmt_listentry(ans_skb, entry);
rcu_read_unlock();
if (ret_val != 0)
goto listdef_failure;
genlmsg_end(ans_skb, data);
return genlmsg_reply(ans_skb, info);
listdef_failure_lock:
rcu_read_unlock();
listdef_failure:
kfree_skb(ans_skb);
return ret_val;
}
/**
* netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
* @skb: the skb to write to
* @cb: the NETLINK callback
* @protocol: the NetLabel protocol to use in the message
*
* Description:
* This function is to be used in conjunction with netlbl_mgmt_protocols() to
* answer a application's PROTOCOLS message. Returns the size of the message
* on success, negative values on failure.
*
*/
static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
struct netlink_callback *cb,
u32 protocol)
{
int ret_val = -ENOMEM;
void *data;
data = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
&netlbl_mgmt_gnl_family, NLM_F_MULTI,
NLBL_MGMT_C_PROTOCOLS);
if (data == NULL)
goto protocols_cb_failure;
ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
if (ret_val != 0)
goto protocols_cb_failure;
netlink: make nlmsg_end() and genlmsg_end() void Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-17 04:09:00 +07:00
genlmsg_end(skb, data);
return 0;
protocols_cb_failure:
genlmsg_cancel(skb, data);
return ret_val;
}
/**
* netlbl_mgmt_protocols - Handle a PROTOCOLS message
* @skb: the NETLINK buffer
* @cb: the NETLINK callback
*
* Description:
* Process a user generated PROTOCOLS message and respond accordingly.
*
*/
static int netlbl_mgmt_protocols(struct sk_buff *skb,
struct netlink_callback *cb)
{
u32 protos_sent = cb->args[0];
if (protos_sent == 0) {
if (netlbl_mgmt_protocols_cb(skb,
cb,
NETLBL_NLTYPE_UNLABELED) < 0)
goto protocols_return;
protos_sent++;
}
if (protos_sent == 1) {
if (netlbl_mgmt_protocols_cb(skb,
cb,
NETLBL_NLTYPE_CIPSOV4) < 0)
goto protocols_return;
protos_sent++;
}
#if IS_ENABLED(CONFIG_IPV6)
if (protos_sent == 2) {
if (netlbl_mgmt_protocols_cb(skb,
cb,
NETLBL_NLTYPE_CALIPSO) < 0)
goto protocols_return;
protos_sent++;
}
#endif
protocols_return:
cb->args[0] = protos_sent;
return skb->len;
}
/**
* netlbl_mgmt_version - Handle a VERSION message
* @skb: the NETLINK buffer
* @info: the Generic NETLINK info block
*
* Description:
* Process a user generated VERSION message and respond accordingly. Returns
* zero on success, negative values on failure.
*
*/
static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
{
int ret_val = -ENOMEM;
struct sk_buff *ans_skb = NULL;
void *data;
ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (ans_skb == NULL)
return -ENOMEM;
data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
0, NLBL_MGMT_C_VERSION);
if (data == NULL)
goto version_failure;
ret_val = nla_put_u32(ans_skb,
NLBL_MGMT_A_VERSION,
NETLBL_PROTO_VERSION);
if (ret_val != 0)
goto version_failure;
genlmsg_end(ans_skb, data);
return genlmsg_reply(ans_skb, info);
version_failure:
kfree_skb(ans_skb);
return ret_val;
}
/*
* NetLabel Generic NETLINK Command Definitions
*/
static const struct genl_ops netlbl_mgmt_genl_ops[] = {
{
.cmd = NLBL_MGMT_C_ADD,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_add,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_REMOVE,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_remove,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_LISTALL,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = NULL,
.dumpit = netlbl_mgmt_listall,
},
{
.cmd = NLBL_MGMT_C_ADDDEF,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_adddef,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_REMOVEDEF,
.flags = GENL_ADMIN_PERM,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_removedef,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_LISTDEF,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_listdef,
.dumpit = NULL,
},
{
.cmd = NLBL_MGMT_C_PROTOCOLS,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = NULL,
.dumpit = netlbl_mgmt_protocols,
},
{
.cmd = NLBL_MGMT_C_VERSION,
.flags = 0,
.policy = netlbl_mgmt_genl_policy,
.doit = netlbl_mgmt_version,
.dumpit = NULL,
},
};
/*
* NetLabel Generic NETLINK Protocol Functions
*/
/**
* netlbl_mgmt_genl_init - Register the NetLabel management component
*
* Description:
* Register the NetLabel management component with the Generic NETLINK
* mechanism. Returns zero on success, negative values on failure.
*
*/
int __init netlbl_mgmt_genl_init(void)
{
return genl_register_family_with_ops(&netlbl_mgmt_gnl_family,
netlbl_mgmt_genl_ops);
}