netfilter: Add helper array register/unregister functions

Add nf_ct_helper_init(), nf_conntrack_helpers_register() and
nf_conntrack_helpers_unregister() functions to avoid repetitive
opencoded initialization in helpers.

This patch keeps an id parameter for nf_ct_helper_init() not to break
helper matching by name that has been inconsistently exposed to
userspace through ports, eg. ftp-2121, and through an incremental id,
eg. tftp-1.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Gao Feng 2016-07-18 11:39:23 +08:00 committed by Pablo Neira Ayuso
parent 590025a27f
commit 82de0be686
7 changed files with 162 additions and 178 deletions

View File

@ -58,10 +58,25 @@ struct nf_conntrack_helper *__nf_conntrack_helper_find(const char *name,
struct nf_conntrack_helper *nf_conntrack_helper_try_module_get(const char *name, struct nf_conntrack_helper *nf_conntrack_helper_try_module_get(const char *name,
u16 l3num, u16 l3num,
u8 protonum); u8 protonum);
void nf_ct_helper_init(struct nf_conntrack_helper *helper,
u16 l3num, u16 protonum, const char *name,
u16 default_port, u16 spec_port, u32 id,
const struct nf_conntrack_expect_policy *exp_pol,
u32 expect_class_max, u32 data_len,
int (*help)(struct sk_buff *skb, unsigned int protoff,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo),
int (*from_nlattr)(struct nlattr *attr,
struct nf_conn *ct),
struct module *module);
int nf_conntrack_helper_register(struct nf_conntrack_helper *); int nf_conntrack_helper_register(struct nf_conntrack_helper *);
void nf_conntrack_helper_unregister(struct nf_conntrack_helper *); void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
int nf_conntrack_helpers_register(struct nf_conntrack_helper *, unsigned int);
void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *,
unsigned int);
struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct,
struct nf_conntrack_helper *helper, struct nf_conntrack_helper *helper,
gfp_t gfp); gfp_t gfp);

View File

@ -572,7 +572,7 @@ static int nf_ct_ftp_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
return 0; return 0;
} }
static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly; static struct nf_conntrack_helper ftp[MAX_PORTS * 2] __read_mostly;
static const struct nf_conntrack_expect_policy ftp_exp_policy = { static const struct nf_conntrack_expect_policy ftp_exp_policy = {
.max_expected = 1, .max_expected = 1,
@ -582,24 +582,13 @@ static const struct nf_conntrack_expect_policy ftp_exp_policy = {
/* don't make this __exit, since it's called from __init ! */ /* don't make this __exit, since it's called from __init ! */
static void nf_conntrack_ftp_fini(void) static void nf_conntrack_ftp_fini(void)
{ {
int i, j; nf_conntrack_helpers_unregister(ftp, ports_c * 2);
for (i = 0; i < ports_c; i++) {
for (j = 0; j < 2; j++) {
if (ftp[i][j].me == NULL)
continue;
pr_debug("unregistering helper for pf: %d port: %d\n",
ftp[i][j].tuple.src.l3num, ports[i]);
nf_conntrack_helper_unregister(&ftp[i][j]);
}
}
kfree(ftp_buffer); kfree(ftp_buffer);
} }
static int __init nf_conntrack_ftp_init(void) static int __init nf_conntrack_ftp_init(void)
{ {
int i, j = -1, ret = 0; int i, ret = 0;
ftp_buffer = kmalloc(65536, GFP_KERNEL); ftp_buffer = kmalloc(65536, GFP_KERNEL);
if (!ftp_buffer) if (!ftp_buffer)
@ -611,32 +600,21 @@ static int __init nf_conntrack_ftp_init(void)
/* FIXME should be configurable whether IPv4 and IPv6 FTP connections /* FIXME should be configurable whether IPv4 and IPv6 FTP connections
are tracked or not - YK */ are tracked or not - YK */
for (i = 0; i < ports_c; i++) { for (i = 0; i < ports_c; i++) {
ftp[i][0].tuple.src.l3num = PF_INET; nf_ct_helper_init(&ftp[2 * i], AF_INET, IPPROTO_TCP, "ftp",
ftp[i][1].tuple.src.l3num = PF_INET6; FTP_PORT, ports[i], ports[i], &ftp_exp_policy,
for (j = 0; j < 2; j++) { 0, sizeof(struct nf_ct_ftp_master), help,
ftp[i][j].data_len = sizeof(struct nf_ct_ftp_master); nf_ct_ftp_from_nlattr, THIS_MODULE);
ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]); nf_ct_helper_init(&ftp[2 * i + 1], AF_INET6, IPPROTO_TCP, "ftp",
ftp[i][j].tuple.dst.protonum = IPPROTO_TCP; FTP_PORT, ports[i], ports[i], &ftp_exp_policy,
ftp[i][j].expect_policy = &ftp_exp_policy; 0, sizeof(struct nf_ct_ftp_master), help,
ftp[i][j].me = THIS_MODULE; nf_ct_ftp_from_nlattr, THIS_MODULE);
ftp[i][j].help = help; }
ftp[i][j].from_nlattr = nf_ct_ftp_from_nlattr;
if (ports[i] == FTP_PORT)
sprintf(ftp[i][j].name, "ftp");
else
sprintf(ftp[i][j].name, "ftp-%d", ports[i]);
pr_debug("registering helper for pf: %d port: %d\n", ret = nf_conntrack_helpers_register(ftp, ports_c * 2);
ftp[i][j].tuple.src.l3num, ports[i]); if (ret < 0) {
ret = nf_conntrack_helper_register(&ftp[i][j]); pr_err("failed to register helpers\n");
if (ret) { kfree(ftp_buffer);
pr_err("failed to register helper for pf: %d port: %d\n", return ret;
ftp[i][j].tuple.src.l3num, ports[i]);
ports_c = i;
nf_conntrack_ftp_fini();
return ret;
}
}
} }
return 0; return 0;

View File

@ -465,6 +465,63 @@ restart:
} }
EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister); EXPORT_SYMBOL_GPL(nf_conntrack_helper_unregister);
void nf_ct_helper_init(struct nf_conntrack_helper *helper,
u16 l3num, u16 protonum, const char *name,
u16 default_port, u16 spec_port, u32 id,
const struct nf_conntrack_expect_policy *exp_pol,
u32 expect_class_max, u32 data_len,
int (*help)(struct sk_buff *skb, unsigned int protoff,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo),
int (*from_nlattr)(struct nlattr *attr,
struct nf_conn *ct),
struct module *module)
{
helper->tuple.src.l3num = l3num;
helper->tuple.dst.protonum = protonum;
helper->tuple.src.u.all = htons(spec_port);
helper->expect_policy = exp_pol;
helper->expect_class_max = expect_class_max;
helper->data_len = data_len;
helper->help = help;
helper->from_nlattr = from_nlattr;
helper->me = module;
if (spec_port == default_port)
snprintf(helper->name, sizeof(helper->name), "%s", name);
else
snprintf(helper->name, sizeof(helper->name), "%s-%u", name, id);
}
EXPORT_SYMBOL_GPL(nf_ct_helper_init);
int nf_conntrack_helpers_register(struct nf_conntrack_helper *helper,
unsigned int n)
{
unsigned int i;
int err = 0;
for (i = 0; i < n; i++) {
err = nf_conntrack_helper_register(&helper[i]);
if (err < 0)
goto err;
}
return err;
err:
if (i > 0)
nf_conntrack_helpers_unregister(helper, i);
return err;
}
EXPORT_SYMBOL_GPL(nf_conntrack_helpers_register);
void nf_conntrack_helpers_unregister(struct nf_conntrack_helper *helper,
unsigned int n)
{
while (n-- > 0)
nf_conntrack_helper_unregister(&helper[n]);
}
EXPORT_SYMBOL_GPL(nf_conntrack_helpers_unregister);
static struct nf_ct_ext_type helper_extend __read_mostly = { static struct nf_ct_ext_type helper_extend __read_mostly = {
.len = sizeof(struct nf_conn_help), .len = sizeof(struct nf_conn_help),
.align = __alignof__(struct nf_conn_help), .align = __alignof__(struct nf_conn_help),

View File

@ -255,27 +255,18 @@ static int __init nf_conntrack_irc_init(void)
ports[ports_c++] = IRC_PORT; ports[ports_c++] = IRC_PORT;
for (i = 0; i < ports_c; i++) { for (i = 0; i < ports_c; i++) {
irc[i].tuple.src.l3num = AF_INET; nf_ct_helper_init(&irc[i], AF_INET, IPPROTO_TCP, "irc",
irc[i].tuple.src.u.tcp.port = htons(ports[i]); IRC_PORT, ports[i], i, &irc_exp_policy,
irc[i].tuple.dst.protonum = IPPROTO_TCP; 0, 0, help, NULL, THIS_MODULE);
irc[i].expect_policy = &irc_exp_policy;
irc[i].me = THIS_MODULE;
irc[i].help = help;
if (ports[i] == IRC_PORT)
sprintf(irc[i].name, "irc");
else
sprintf(irc[i].name, "irc-%u", i);
ret = nf_conntrack_helper_register(&irc[i]);
if (ret) {
pr_err("failed to register helper for pf: %u port: %u\n",
irc[i].tuple.src.l3num, ports[i]);
ports_c = i;
nf_conntrack_irc_fini();
return ret;
}
} }
ret = nf_conntrack_helpers_register(&irc[0], ports_c);
if (ret) {
pr_err("failed to register helpers\n");
kfree(irc_buffer);
return ret;
}
return 0; return 0;
} }
@ -283,10 +274,7 @@ static int __init nf_conntrack_irc_init(void)
* it is needed by the init function */ * it is needed by the init function */
static void nf_conntrack_irc_fini(void) static void nf_conntrack_irc_fini(void)
{ {
int i; nf_conntrack_helpers_unregister(irc, ports_c);
for (i = 0; i < ports_c; i++)
nf_conntrack_helper_unregister(&irc[i]);
kfree(irc_buffer); kfree(irc_buffer);
} }

View File

@ -166,7 +166,7 @@ out:
return ret; return ret;
} }
static struct nf_conntrack_helper sane[MAX_PORTS][2] __read_mostly; static struct nf_conntrack_helper sane[MAX_PORTS * 2] __read_mostly;
static const struct nf_conntrack_expect_policy sane_exp_policy = { static const struct nf_conntrack_expect_policy sane_exp_policy = {
.max_expected = 1, .max_expected = 1,
@ -176,22 +176,13 @@ static const struct nf_conntrack_expect_policy sane_exp_policy = {
/* don't make this __exit, since it's called from __init ! */ /* don't make this __exit, since it's called from __init ! */
static void nf_conntrack_sane_fini(void) static void nf_conntrack_sane_fini(void)
{ {
int i, j; nf_conntrack_helpers_unregister(sane, ports_c * 2);
for (i = 0; i < ports_c; i++) {
for (j = 0; j < 2; j++) {
pr_debug("unregistering helper for pf: %d port: %d\n",
sane[i][j].tuple.src.l3num, ports[i]);
nf_conntrack_helper_unregister(&sane[i][j]);
}
}
kfree(sane_buffer); kfree(sane_buffer);
} }
static int __init nf_conntrack_sane_init(void) static int __init nf_conntrack_sane_init(void)
{ {
int i, j = -1, ret = 0; int i, ret = 0;
sane_buffer = kmalloc(65536, GFP_KERNEL); sane_buffer = kmalloc(65536, GFP_KERNEL);
if (!sane_buffer) if (!sane_buffer)
@ -203,31 +194,23 @@ static int __init nf_conntrack_sane_init(void)
/* FIXME should be configurable whether IPv4 and IPv6 connections /* FIXME should be configurable whether IPv4 and IPv6 connections
are tracked or not - YK */ are tracked or not - YK */
for (i = 0; i < ports_c; i++) { for (i = 0; i < ports_c; i++) {
sane[i][0].tuple.src.l3num = PF_INET; nf_ct_helper_init(&sane[2 * i], AF_INET, IPPROTO_TCP, "sane",
sane[i][1].tuple.src.l3num = PF_INET6; SANE_PORT, ports[i], ports[i],
for (j = 0; j < 2; j++) { &sane_exp_policy, 0,
sane[i][j].data_len = sizeof(struct nf_ct_sane_master); sizeof(struct nf_ct_sane_master), help, NULL,
sane[i][j].tuple.src.u.tcp.port = htons(ports[i]); THIS_MODULE);
sane[i][j].tuple.dst.protonum = IPPROTO_TCP; nf_ct_helper_init(&sane[2 * i + 1], AF_INET6, IPPROTO_TCP, "sane",
sane[i][j].expect_policy = &sane_exp_policy; SANE_PORT, ports[i], ports[i],
sane[i][j].me = THIS_MODULE; &sane_exp_policy, 0,
sane[i][j].help = help; sizeof(struct nf_ct_sane_master), help, NULL,
if (ports[i] == SANE_PORT) THIS_MODULE);
sprintf(sane[i][j].name, "sane"); }
else
sprintf(sane[i][j].name, "sane-%d", ports[i]);
pr_debug("registering helper for pf: %d port: %d\n", ret = nf_conntrack_helpers_register(sane, ports_c * 2);
sane[i][j].tuple.src.l3num, ports[i]); if (ret < 0) {
ret = nf_conntrack_helper_register(&sane[i][j]); pr_err("failed to register helpers\n");
if (ret) { kfree(sane_buffer);
pr_err("failed to register helper for pf: %d port: %d\n", return ret;
sane[i][j].tuple.src.l3num, ports[i]);
ports_c = i;
nf_conntrack_sane_fini();
return ret;
}
}
} }
return 0; return 0;

View File

@ -1589,7 +1589,7 @@ static int sip_help_udp(struct sk_buff *skb, unsigned int protoff,
return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen); return process_sip_msg(skb, ct, protoff, dataoff, &dptr, &datalen);
} }
static struct nf_conntrack_helper sip[MAX_PORTS][4] __read_mostly; static struct nf_conntrack_helper sip[MAX_PORTS * 4] __read_mostly;
static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = { static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1] = {
[SIP_EXPECT_SIGNALLING] = { [SIP_EXPECT_SIGNALLING] = {
@ -1616,20 +1616,12 @@ static const struct nf_conntrack_expect_policy sip_exp_policy[SIP_EXPECT_MAX + 1
static void nf_conntrack_sip_fini(void) static void nf_conntrack_sip_fini(void)
{ {
int i, j; nf_conntrack_helpers_unregister(sip, ports_c * 4);
for (i = 0; i < ports_c; i++) {
for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
if (sip[i][j].me == NULL)
continue;
nf_conntrack_helper_unregister(&sip[i][j]);
}
}
} }
static int __init nf_conntrack_sip_init(void) static int __init nf_conntrack_sip_init(void)
{ {
int i, j, ret; int i, ret;
if (ports_c == 0) if (ports_c == 0)
ports[ports_c++] = SIP_PORT; ports[ports_c++] = SIP_PORT;
@ -1637,43 +1629,32 @@ static int __init nf_conntrack_sip_init(void)
for (i = 0; i < ports_c; i++) { for (i = 0; i < ports_c; i++) {
memset(&sip[i], 0, sizeof(sip[i])); memset(&sip[i], 0, sizeof(sip[i]));
sip[i][0].tuple.src.l3num = AF_INET; nf_ct_helper_init(&sip[4 * i], AF_INET, IPPROTO_UDP, "sip",
sip[i][0].tuple.dst.protonum = IPPROTO_UDP; SIP_PORT, ports[i], i, sip_exp_policy,
sip[i][0].help = sip_help_udp; SIP_EXPECT_MAX,
sip[i][1].tuple.src.l3num = AF_INET; sizeof(struct nf_ct_sip_master), sip_help_udp,
sip[i][1].tuple.dst.protonum = IPPROTO_TCP; NULL, THIS_MODULE);
sip[i][1].help = sip_help_tcp; nf_ct_helper_init(&sip[4 * i + 1], AF_INET, IPPROTO_TCP, "sip",
SIP_PORT, ports[i], i, sip_exp_policy,
SIP_EXPECT_MAX,
sizeof(struct nf_ct_sip_master), sip_help_tcp,
NULL, THIS_MODULE);
nf_ct_helper_init(&sip[4 * i + 2], AF_INET6, IPPROTO_UDP, "sip",
SIP_PORT, ports[i], i, sip_exp_policy,
SIP_EXPECT_MAX,
sizeof(struct nf_ct_sip_master), sip_help_udp,
NULL, THIS_MODULE);
nf_ct_helper_init(&sip[4 * i + 3], AF_INET6, IPPROTO_TCP, "sip",
SIP_PORT, ports[i], i, sip_exp_policy,
SIP_EXPECT_MAX,
sizeof(struct nf_ct_sip_master), sip_help_tcp,
NULL, THIS_MODULE);
}
sip[i][2].tuple.src.l3num = AF_INET6; ret = nf_conntrack_helpers_register(sip, ports_c * 4);
sip[i][2].tuple.dst.protonum = IPPROTO_UDP; if (ret < 0) {
sip[i][2].help = sip_help_udp; pr_err("failed to register helpers\n");
sip[i][3].tuple.src.l3num = AF_INET6; return ret;
sip[i][3].tuple.dst.protonum = IPPROTO_TCP;
sip[i][3].help = sip_help_tcp;
for (j = 0; j < ARRAY_SIZE(sip[i]); j++) {
sip[i][j].data_len = sizeof(struct nf_ct_sip_master);
sip[i][j].tuple.src.u.udp.port = htons(ports[i]);
sip[i][j].expect_policy = sip_exp_policy;
sip[i][j].expect_class_max = SIP_EXPECT_MAX;
sip[i][j].me = THIS_MODULE;
if (ports[i] == SIP_PORT)
sprintf(sip[i][j].name, "sip");
else
sprintf(sip[i][j].name, "sip-%u", i);
pr_debug("port #%u: %u\n", i, ports[i]);
ret = nf_conntrack_helper_register(&sip[i][j]);
if (ret) {
pr_err("failed to register helper for pf: %u port: %u\n",
sip[i][j].tuple.src.l3num, ports[i]);
ports_c = i;
nf_conntrack_sip_fini();
return ret;
}
}
} }
return 0; return 0;
} }

View File

@ -97,7 +97,7 @@ static int tftp_help(struct sk_buff *skb,
return ret; return ret;
} }
static struct nf_conntrack_helper tftp[MAX_PORTS][2] __read_mostly; static struct nf_conntrack_helper tftp[MAX_PORTS * 2] __read_mostly;
static const struct nf_conntrack_expect_policy tftp_exp_policy = { static const struct nf_conntrack_expect_policy tftp_exp_policy = {
.max_expected = 1, .max_expected = 1,
@ -106,47 +106,29 @@ static const struct nf_conntrack_expect_policy tftp_exp_policy = {
static void nf_conntrack_tftp_fini(void) static void nf_conntrack_tftp_fini(void)
{ {
int i, j; nf_conntrack_helpers_unregister(tftp, ports_c * 2);
for (i = 0; i < ports_c; i++) {
for (j = 0; j < 2; j++)
nf_conntrack_helper_unregister(&tftp[i][j]);
}
} }
static int __init nf_conntrack_tftp_init(void) static int __init nf_conntrack_tftp_init(void)
{ {
int i, j, ret; int i, ret;
if (ports_c == 0) if (ports_c == 0)
ports[ports_c++] = TFTP_PORT; ports[ports_c++] = TFTP_PORT;
for (i = 0; i < ports_c; i++) { for (i = 0; i < ports_c; i++) {
memset(&tftp[i], 0, sizeof(tftp[i])); nf_ct_helper_init(&tftp[2 * i], AF_INET, IPPROTO_UDP, "tftp",
TFTP_PORT, ports[i], i, &tftp_exp_policy,
0, 0, tftp_help, NULL, THIS_MODULE);
nf_ct_helper_init(&tftp[2 * i + 1], AF_INET6, IPPROTO_UDP, "tftp",
TFTP_PORT, ports[i], i, &tftp_exp_policy,
0, 0, tftp_help, NULL, THIS_MODULE);
}
tftp[i][0].tuple.src.l3num = AF_INET; ret = nf_conntrack_helpers_register(tftp, ports_c * 2);
tftp[i][1].tuple.src.l3num = AF_INET6; if (ret < 0) {
for (j = 0; j < 2; j++) { pr_err("failed to register helpers\n");
tftp[i][j].tuple.dst.protonum = IPPROTO_UDP; return ret;
tftp[i][j].tuple.src.u.udp.port = htons(ports[i]);
tftp[i][j].expect_policy = &tftp_exp_policy;
tftp[i][j].me = THIS_MODULE;
tftp[i][j].help = tftp_help;
if (ports[i] == TFTP_PORT)
sprintf(tftp[i][j].name, "tftp");
else
sprintf(tftp[i][j].name, "tftp-%u", i);
ret = nf_conntrack_helper_register(&tftp[i][j]);
if (ret) {
pr_err("failed to register helper for pf: %u port: %u\n",
tftp[i][j].tuple.src.l3num, ports[i]);
ports_c = i;
nf_conntrack_tftp_fini();
return ret;
}
}
} }
return 0; return 0;
} }