struct ip_comp_hdr;
struct sk_buff;
+struct xfrm_state;
+
+int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb);
+int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb);
+void ipcomp_destroy(struct xfrm_state *x);
+int ipcomp_init_state(struct xfrm_state *x);
static inline struct ip_comp_hdr *ip_comp_hdr(const struct sk_buff *skb)
{
config INET_IPCOMP
tristate "IP: IPComp transformation"
- select XFRM
select INET_XFRM_TUNNEL
- select CRYPTO
- select CRYPTO_DEFLATE
+ select XFRM_IPCOMP
---help---
Support for IP Payload Compression Protocol (IPComp) (RFC3173),
typically needed for IPsec.
* - Adaptive compression.
*/
#include <linux/module.h>
-#include <linux/crypto.h>
#include <linux/err.h>
-#include <linux/pfkeyv2.h>
-#include <linux/percpu.h>
-#include <linux/smp.h>
-#include <linux/list.h>
-#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
-#include <linux/mutex.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/icmp.h>
#include <net/ipcomp.h>
#include <net/protocol.h>
-
-struct ipcomp_tfms {
- struct list_head list;
- struct crypto_comp **tfms;
- int users;
-};
-
-static DEFINE_MUTEX(ipcomp_resource_mutex);
-static void **ipcomp_scratches;
-static int ipcomp_scratch_users;
-static LIST_HEAD(ipcomp_tfms_list);
-
-static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
-{
- struct ipcomp_data *ipcd = x->data;
- const int plen = skb->len;
- int dlen = IPCOMP_SCRATCH_SIZE;
- const u8 *start = skb->data;
- const int cpu = get_cpu();
- u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
- struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
- int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
-
- if (err)
- goto out;
-
- if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
- err = -EINVAL;
- goto out;
- }
-
- err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
- if (err)
- goto out;
-
- skb->truesize += dlen - plen;
- __skb_put(skb, dlen - plen);
- skb_copy_to_linear_data(skb, scratch, dlen);
-out:
- put_cpu();
- return err;
-}
-
-static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
-{
- int nexthdr;
- int err = -ENOMEM;
- struct ip_comp_hdr *ipch;
-
- if (skb_linearize_cow(skb))
- goto out;
-
- skb->ip_summed = CHECKSUM_NONE;
-
- /* Remove ipcomp header and decompress original payload */
- ipch = (void *)skb->data;
- nexthdr = ipch->nexthdr;
-
- skb->transport_header = skb->network_header + sizeof(*ipch);
- __skb_pull(skb, sizeof(*ipch));
- err = ipcomp_decompress(x, skb);
- if (err)
- goto out;
-
- err = nexthdr;
-
-out:
- return err;
-}
-
-static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
-{
- struct ipcomp_data *ipcd = x->data;
- const int plen = skb->len;
- int dlen = IPCOMP_SCRATCH_SIZE;
- u8 *start = skb->data;
- const int cpu = get_cpu();
- u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
- struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
- int err;
-
- local_bh_disable();
- err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
- local_bh_enable();
- if (err)
- goto out;
-
- if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
- err = -EMSGSIZE;
- goto out;
- }
-
- memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
- put_cpu();
-
- pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
- return 0;
-
-out:
- put_cpu();
- return err;
-}
-
-static int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
-{
- int err;
- struct ip_comp_hdr *ipch;
- struct ipcomp_data *ipcd = x->data;
-
- if (skb->len < ipcd->threshold) {
- /* Don't bother compressing */
- goto out_ok;
- }
-
- if (skb_linearize_cow(skb))
- goto out_ok;
-
- err = ipcomp_compress(x, skb);
-
- if (err) {
- goto out_ok;
- }
-
- /* Install ipcomp header, convert into ipcomp datagram. */
- ipch = ip_comp_hdr(skb);
- ipch->nexthdr = *skb_mac_header(skb);
- ipch->flags = 0;
- ipch->cpi = htons((u16 )ntohl(x->id.spi));
- *skb_mac_header(skb) = IPPROTO_COMP;
-out_ok:
- skb_push(skb, -skb_network_offset(skb));
- return 0;
-}
+#include <net/sock.h>
static void ipcomp4_err(struct sk_buff *skb, u32 info)
{
return err;
}
-static void ipcomp_free_scratches(void)
-{
- int i;
- void **scratches;
-
- if (--ipcomp_scratch_users)
- return;
-
- scratches = ipcomp_scratches;
- if (!scratches)
- return;
-
- for_each_possible_cpu(i)
- vfree(*per_cpu_ptr(scratches, i));
-
- free_percpu(scratches);
-}
-
-static void **ipcomp_alloc_scratches(void)
-{
- int i;
- void **scratches;
-
- if (ipcomp_scratch_users++)
- return ipcomp_scratches;
-
- scratches = alloc_percpu(void *);
- if (!scratches)
- return NULL;
-
- ipcomp_scratches = scratches;
-
- for_each_possible_cpu(i) {
- void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
- if (!scratch)
- return NULL;
- *per_cpu_ptr(scratches, i) = scratch;
- }
-
- return scratches;
-}
-
-static void ipcomp_free_tfms(struct crypto_comp **tfms)
-{
- struct ipcomp_tfms *pos;
- int cpu;
-
- list_for_each_entry(pos, &ipcomp_tfms_list, list) {
- if (pos->tfms == tfms)
- break;
- }
-
- BUG_TRAP(pos);
-
- if (--pos->users)
- return;
-
- list_del(&pos->list);
- kfree(pos);
-
- if (!tfms)
- return;
-
- for_each_possible_cpu(cpu) {
- struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
- crypto_free_comp(tfm);
- }
- free_percpu(tfms);
-}
-
-static struct crypto_comp **ipcomp_alloc_tfms(const char *alg_name)
-{
- struct ipcomp_tfms *pos;
- struct crypto_comp **tfms;
- int cpu;
-
- /* This can be any valid CPU ID so we don't need locking. */
- cpu = raw_smp_processor_id();
-
- list_for_each_entry(pos, &ipcomp_tfms_list, list) {
- struct crypto_comp *tfm;
-
- tfms = pos->tfms;
- tfm = *per_cpu_ptr(tfms, cpu);
-
- if (!strcmp(crypto_comp_name(tfm), alg_name)) {
- pos->users++;
- return tfms;
- }
- }
-
- pos = kmalloc(sizeof(*pos), GFP_KERNEL);
- if (!pos)
- return NULL;
-
- pos->users = 1;
- INIT_LIST_HEAD(&pos->list);
- list_add(&pos->list, &ipcomp_tfms_list);
-
- pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
- if (!tfms)
- goto error;
-
- for_each_possible_cpu(cpu) {
- struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
- CRYPTO_ALG_ASYNC);
- if (IS_ERR(tfm))
- goto error;
- *per_cpu_ptr(tfms, cpu) = tfm;
- }
-
- return tfms;
-
-error:
- ipcomp_free_tfms(tfms);
- return NULL;
-}
-
-static void ipcomp_free_data(struct ipcomp_data *ipcd)
-{
- if (ipcd->tfms)
- ipcomp_free_tfms(ipcd->tfms);
- ipcomp_free_scratches();
-}
-
-static void ipcomp_destroy(struct xfrm_state *x)
-{
- struct ipcomp_data *ipcd = x->data;
- if (!ipcd)
- return;
- xfrm_state_delete_tunnel(x);
- mutex_lock(&ipcomp_resource_mutex);
- ipcomp_free_data(ipcd);
- mutex_unlock(&ipcomp_resource_mutex);
- kfree(ipcd);
-}
-
-static int ipcomp_init_state(struct xfrm_state *x)
+static int ipcomp4_init_state(struct xfrm_state *x)
{
int err;
struct ipcomp_data *ipcd;
struct xfrm_algo_desc *calg_desc;
- err = -EINVAL;
- if (!x->calg)
- goto out;
-
- if (x->encap)
- goto out;
-
x->props.header_len = 0;
switch (x->props.mode) {
case XFRM_MODE_TRANSPORT:
goto out;
}
- err = -ENOMEM;
- ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
- if (!ipcd)
+ err = ipcomp_init_state(x);
+ if (err)
goto out;
- mutex_lock(&ipcomp_resource_mutex);
- if (!ipcomp_alloc_scratches())
- goto error;
-
- ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
- if (!ipcd->tfms)
- goto error;
- mutex_unlock(&ipcomp_resource_mutex);
-
if (x->props.mode == XFRM_MODE_TUNNEL) {
err = ipcomp_tunnel_attach(x);
if (err)
goto error_tunnel;
}
- calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
- BUG_ON(!calg_desc);
- ipcd->threshold = calg_desc->uinfo.comp.threshold;
- x->data = ipcd;
err = 0;
out:
return err;
error_tunnel:
- mutex_lock(&ipcomp_resource_mutex);
-error:
- ipcomp_free_data(ipcd);
- mutex_unlock(&ipcomp_resource_mutex);
- kfree(ipcd);
+ ipcomp_destroy(x);
goto out;
}
.description = "IPCOMP4",
.owner = THIS_MODULE,
.proto = IPPROTO_COMP,
- .init_state = ipcomp_init_state,
+ .init_state = ipcomp4_init_state,
.destructor = ipcomp_destroy,
.input = ipcomp_input,
.output = ipcomp_output
module_exit(ipcomp4_fini);
MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
+MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);
config INET6_IPCOMP
tristate "IPv6: IPComp transformation"
- select XFRM
select INET6_XFRM_TUNNEL
- select CRYPTO
- select CRYPTO_DEFLATE
+ select XFRM_IPCOMP
---help---
Support for IP Payload Compression Protocol (IPComp) (RFC3173),
typically needed for IPsec.
#include <linux/icmpv6.h>
#include <linux/mutex.h>
-struct ipcomp6_tfms {
- struct list_head list;
- struct crypto_comp **tfms;
- int users;
-};
-
-static DEFINE_MUTEX(ipcomp6_resource_mutex);
-static void **ipcomp6_scratches;
-static int ipcomp6_scratch_users;
-static LIST_HEAD(ipcomp6_tfms_list);
-
-static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb)
-{
- int nexthdr;
- int err = -ENOMEM;
- struct ip_comp_hdr *ipch;
- int plen, dlen;
- struct ipcomp_data *ipcd = x->data;
- u8 *start, *scratch;
- struct crypto_comp *tfm;
- int cpu;
-
- if (skb_linearize_cow(skb))
- goto out;
-
- skb->ip_summed = CHECKSUM_NONE;
-
- /* Remove ipcomp header and decompress original payload */
- ipch = (void *)skb->data;
- nexthdr = ipch->nexthdr;
-
- skb->transport_header = skb->network_header + sizeof(*ipch);
- __skb_pull(skb, sizeof(*ipch));
-
- /* decompression */
- plen = skb->len;
- dlen = IPCOMP_SCRATCH_SIZE;
- start = skb->data;
-
- cpu = get_cpu();
- scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
- tfm = *per_cpu_ptr(ipcd->tfms, cpu);
-
- err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
- if (err)
- goto out_put_cpu;
-
- if (dlen < (plen + sizeof(*ipch))) {
- err = -EINVAL;
- goto out_put_cpu;
- }
-
- err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
- if (err) {
- goto out_put_cpu;
- }
-
- skb->truesize += dlen - plen;
- __skb_put(skb, dlen - plen);
- skb_copy_to_linear_data(skb, scratch, dlen);
- err = nexthdr;
-
-out_put_cpu:
- put_cpu();
-out:
- return err;
-}
-
-static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb)
-{
- int err;
- struct ip_comp_hdr *ipch;
- struct ipcomp_data *ipcd = x->data;
- int plen, dlen;
- u8 *start, *scratch;
- struct crypto_comp *tfm;
- int cpu;
-
- /* check whether datagram len is larger than threshold */
- if (skb->len < ipcd->threshold) {
- goto out_ok;
- }
-
- if (skb_linearize_cow(skb))
- goto out_ok;
-
- /* compression */
- plen = skb->len;
- dlen = IPCOMP_SCRATCH_SIZE;
- start = skb->data;
-
- cpu = get_cpu();
- scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
- tfm = *per_cpu_ptr(ipcd->tfms, cpu);
-
- local_bh_disable();
- err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
- local_bh_enable();
- if (err || (dlen + sizeof(*ipch)) >= plen) {
- put_cpu();
- goto out_ok;
- }
- memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
- put_cpu();
- pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
-
- /* insert ipcomp header and replace datagram */
- ipch = ip_comp_hdr(skb);
- ipch->nexthdr = *skb_mac_header(skb);
- ipch->flags = 0;
- ipch->cpi = htons((u16 )ntohl(x->id.spi));
- *skb_mac_header(skb) = IPPROTO_COMP;
-
-out_ok:
- skb_push(skb, -skb_network_offset(skb));
-
- return 0;
-}
-
static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __be32 info)
{
return err;
}
-static void ipcomp6_free_scratches(void)
-{
- int i;
- void **scratches;
-
- if (--ipcomp6_scratch_users)
- return;
-
- scratches = ipcomp6_scratches;
- if (!scratches)
- return;
-
- for_each_possible_cpu(i) {
- void *scratch = *per_cpu_ptr(scratches, i);
-
- vfree(scratch);
- }
-
- free_percpu(scratches);
-}
-
-static void **ipcomp6_alloc_scratches(void)
-{
- int i;
- void **scratches;
-
- if (ipcomp6_scratch_users++)
- return ipcomp6_scratches;
-
- scratches = alloc_percpu(void *);
- if (!scratches)
- return NULL;
-
- ipcomp6_scratches = scratches;
-
- for_each_possible_cpu(i) {
- void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
- if (!scratch)
- return NULL;
- *per_cpu_ptr(scratches, i) = scratch;
- }
-
- return scratches;
-}
-
-static void ipcomp6_free_tfms(struct crypto_comp **tfms)
-{
- struct ipcomp6_tfms *pos;
- int cpu;
-
- list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
- if (pos->tfms == tfms)
- break;
- }
-
- BUG_TRAP(pos);
-
- if (--pos->users)
- return;
-
- list_del(&pos->list);
- kfree(pos);
-
- if (!tfms)
- return;
-
- for_each_possible_cpu(cpu) {
- struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
- crypto_free_comp(tfm);
- }
- free_percpu(tfms);
-}
-
-static struct crypto_comp **ipcomp6_alloc_tfms(const char *alg_name)
-{
- struct ipcomp6_tfms *pos;
- struct crypto_comp **tfms;
- int cpu;
-
- /* This can be any valid CPU ID so we don't need locking. */
- cpu = raw_smp_processor_id();
-
- list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
- struct crypto_comp *tfm;
-
- tfms = pos->tfms;
- tfm = *per_cpu_ptr(tfms, cpu);
-
- if (!strcmp(crypto_comp_name(tfm), alg_name)) {
- pos->users++;
- return tfms;
- }
- }
-
- pos = kmalloc(sizeof(*pos), GFP_KERNEL);
- if (!pos)
- return NULL;
-
- pos->users = 1;
- INIT_LIST_HEAD(&pos->list);
- list_add(&pos->list, &ipcomp6_tfms_list);
-
- pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
- if (!tfms)
- goto error;
-
- for_each_possible_cpu(cpu) {
- struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
- CRYPTO_ALG_ASYNC);
- if (IS_ERR(tfm))
- goto error;
- *per_cpu_ptr(tfms, cpu) = tfm;
- }
-
- return tfms;
-
-error:
- ipcomp6_free_tfms(tfms);
- return NULL;
-}
-
-static void ipcomp6_free_data(struct ipcomp_data *ipcd)
-{
- if (ipcd->tfms)
- ipcomp6_free_tfms(ipcd->tfms);
- ipcomp6_free_scratches();
-}
-
-static void ipcomp6_destroy(struct xfrm_state *x)
-{
- struct ipcomp_data *ipcd = x->data;
- if (!ipcd)
- return;
- xfrm_state_delete_tunnel(x);
- mutex_lock(&ipcomp6_resource_mutex);
- ipcomp6_free_data(ipcd);
- mutex_unlock(&ipcomp6_resource_mutex);
- kfree(ipcd);
-
- xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
-}
-
static int ipcomp6_init_state(struct xfrm_state *x)
{
int err;
struct ipcomp_data *ipcd;
struct xfrm_algo_desc *calg_desc;
- err = -EINVAL;
- if (!x->calg)
- goto out;
-
- if (x->encap)
- goto out;
-
x->props.header_len = 0;
switch (x->props.mode) {
case XFRM_MODE_TRANSPORT:
goto out;
}
- err = -ENOMEM;
- ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
- if (!ipcd)
+ err = ipcomp_init_state(x);
+ if (err)
goto out;
- mutex_lock(&ipcomp6_resource_mutex);
- if (!ipcomp6_alloc_scratches())
- goto error;
-
- ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
- if (!ipcd->tfms)
- goto error;
- mutex_unlock(&ipcomp6_resource_mutex);
-
if (x->props.mode == XFRM_MODE_TUNNEL) {
err = ipcomp6_tunnel_attach(x);
if (err)
goto error_tunnel;
}
- calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
- BUG_ON(!calg_desc);
- ipcd->threshold = calg_desc->uinfo.comp.threshold;
- x->data = ipcd;
err = 0;
out:
return err;
error_tunnel:
- mutex_lock(&ipcomp6_resource_mutex);
-error:
- ipcomp6_free_data(ipcd);
- mutex_unlock(&ipcomp6_resource_mutex);
- kfree(ipcd);
+ ipcomp_destroy(x);
goto out;
}
.owner = THIS_MODULE,
.proto = IPPROTO_COMP,
.init_state = ipcomp6_init_state,
- .destructor = ipcomp6_destroy,
- .input = ipcomp6_input,
- .output = ipcomp6_output,
+ .destructor = ipcomp_destroy,
+ .input = ipcomp_input,
+ .output = ipcomp_output,
.hdr_offset = xfrm6_find_1stfragopt,
};
If unsure, say N.
+config XFRM_IPCOMP
+ tristate
+ select XFRM
+ select CRYPTO
+ select CRYPTO_DEFLATE
+
config NET_KEY
tristate "PF_KEY sockets"
select XFRM
xfrm_input.o xfrm_output.o xfrm_algo.o
obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o
obj-$(CONFIG_XFRM_USER) += xfrm_user.o
+obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
--- /dev/null
+/*
+ * IP Payload Compression Protocol (IPComp) - RFC3173.
+ *
+ * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
+ * Copyright (c) 2003-2008 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * 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.
+ *
+ * Todo:
+ * - Tunable compression parameters.
+ * - Compression stats.
+ * - Adaptive compression.
+ */
+
+#include <linux/crypto.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/percpu.h>
+#include <linux/rtnetlink.h>
+#include <linux/smp.h>
+#include <linux/vmalloc.h>
+#include <net/ip.h>
+#include <net/ipcomp.h>
+#include <net/xfrm.h>
+
+struct ipcomp_tfms {
+ struct list_head list;
+ struct crypto_comp **tfms;
+ int users;
+};
+
+static DEFINE_MUTEX(ipcomp_resource_mutex);
+static void **ipcomp_scratches;
+static int ipcomp_scratch_users;
+static LIST_HEAD(ipcomp_tfms_list);
+
+static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ipcomp_data *ipcd = x->data;
+ const int plen = skb->len;
+ int dlen = IPCOMP_SCRATCH_SIZE;
+ const u8 *start = skb->data;
+ const int cpu = get_cpu();
+ u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
+ struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
+ int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
+
+ if (err)
+ goto out;
+
+ if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
+ if (err)
+ goto out;
+
+ skb->truesize += dlen - plen;
+ __skb_put(skb, dlen - plen);
+ skb_copy_to_linear_data(skb, scratch, dlen);
+out:
+ put_cpu();
+ return err;
+}
+
+int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int nexthdr;
+ int err = -ENOMEM;
+ struct ip_comp_hdr *ipch;
+
+ if (skb_linearize_cow(skb))
+ goto out;
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ /* Remove ipcomp header and decompress original payload */
+ ipch = (void *)skb->data;
+ nexthdr = ipch->nexthdr;
+
+ skb->transport_header = skb->network_header + sizeof(*ipch);
+ __skb_pull(skb, sizeof(*ipch));
+ err = ipcomp_decompress(x, skb);
+ if (err)
+ goto out;
+
+ err = nexthdr;
+
+out:
+ return err;
+}
+EXPORT_SYMBOL_GPL(ipcomp_input);
+
+static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ipcomp_data *ipcd = x->data;
+ const int plen = skb->len;
+ int dlen = IPCOMP_SCRATCH_SIZE;
+ u8 *start = skb->data;
+ const int cpu = get_cpu();
+ u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
+ struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
+ int err;
+
+ local_bh_disable();
+ err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
+ local_bh_enable();
+ if (err)
+ goto out;
+
+ if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
+ err = -EMSGSIZE;
+ goto out;
+ }
+
+ memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
+ put_cpu();
+
+ pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
+ return 0;
+
+out:
+ put_cpu();
+ return err;
+}
+
+int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ int err;
+ struct ip_comp_hdr *ipch;
+ struct ipcomp_data *ipcd = x->data;
+
+ if (skb->len < ipcd->threshold) {
+ /* Don't bother compressing */
+ goto out_ok;
+ }
+
+ if (skb_linearize_cow(skb))
+ goto out_ok;
+
+ err = ipcomp_compress(x, skb);
+
+ if (err) {
+ goto out_ok;
+ }
+
+ /* Install ipcomp header, convert into ipcomp datagram. */
+ ipch = ip_comp_hdr(skb);
+ ipch->nexthdr = *skb_mac_header(skb);
+ ipch->flags = 0;
+ ipch->cpi = htons((u16 )ntohl(x->id.spi));
+ *skb_mac_header(skb) = IPPROTO_COMP;
+out_ok:
+ skb_push(skb, -skb_network_offset(skb));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ipcomp_output);
+
+static void ipcomp_free_scratches(void)
+{
+ int i;
+ void **scratches;
+
+ if (--ipcomp_scratch_users)
+ return;
+
+ scratches = ipcomp_scratches;
+ if (!scratches)
+ return;
+
+ for_each_possible_cpu(i)
+ vfree(*per_cpu_ptr(scratches, i));
+
+ free_percpu(scratches);
+}
+
+static void **ipcomp_alloc_scratches(void)
+{
+ int i;
+ void **scratches;
+
+ if (ipcomp_scratch_users++)
+ return ipcomp_scratches;
+
+ scratches = alloc_percpu(void *);
+ if (!scratches)
+ return NULL;
+
+ ipcomp_scratches = scratches;
+
+ for_each_possible_cpu(i) {
+ void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
+ if (!scratch)
+ return NULL;
+ *per_cpu_ptr(scratches, i) = scratch;
+ }
+
+ return scratches;
+}
+
+static void ipcomp_free_tfms(struct crypto_comp **tfms)
+{
+ struct ipcomp_tfms *pos;
+ int cpu;
+
+ list_for_each_entry(pos, &ipcomp_tfms_list, list) {
+ if (pos->tfms == tfms)
+ break;
+ }
+
+ BUG_TRAP(pos);
+
+ if (--pos->users)
+ return;
+
+ list_del(&pos->list);
+ kfree(pos);
+
+ if (!tfms)
+ return;
+
+ for_each_possible_cpu(cpu) {
+ struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
+ crypto_free_comp(tfm);
+ }
+ free_percpu(tfms);
+}
+
+static struct crypto_comp **ipcomp_alloc_tfms(const char *alg_name)
+{
+ struct ipcomp_tfms *pos;
+ struct crypto_comp **tfms;
+ int cpu;
+
+ /* This can be any valid CPU ID so we don't need locking. */
+ cpu = raw_smp_processor_id();
+
+ list_for_each_entry(pos, &ipcomp_tfms_list, list) {
+ struct crypto_comp *tfm;
+
+ tfms = pos->tfms;
+ tfm = *per_cpu_ptr(tfms, cpu);
+
+ if (!strcmp(crypto_comp_name(tfm), alg_name)) {
+ pos->users++;
+ return tfms;
+ }
+ }
+
+ pos = kmalloc(sizeof(*pos), GFP_KERNEL);
+ if (!pos)
+ return NULL;
+
+ pos->users = 1;
+ INIT_LIST_HEAD(&pos->list);
+ list_add(&pos->list, &ipcomp_tfms_list);
+
+ pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
+ if (!tfms)
+ goto error;
+
+ for_each_possible_cpu(cpu) {
+ struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
+ CRYPTO_ALG_ASYNC);
+ if (IS_ERR(tfm))
+ goto error;
+ *per_cpu_ptr(tfms, cpu) = tfm;
+ }
+
+ return tfms;
+
+error:
+ ipcomp_free_tfms(tfms);
+ return NULL;
+}
+
+static void ipcomp_free_data(struct ipcomp_data *ipcd)
+{
+ if (ipcd->tfms)
+ ipcomp_free_tfms(ipcd->tfms);
+ ipcomp_free_scratches();
+}
+
+void ipcomp_destroy(struct xfrm_state *x)
+{
+ struct ipcomp_data *ipcd = x->data;
+ if (!ipcd)
+ return;
+ xfrm_state_delete_tunnel(x);
+ mutex_lock(&ipcomp_resource_mutex);
+ ipcomp_free_data(ipcd);
+ mutex_unlock(&ipcomp_resource_mutex);
+ kfree(ipcd);
+}
+EXPORT_SYMBOL_GPL(ipcomp_destroy);
+
+int ipcomp_init_state(struct xfrm_state *x)
+{
+ int err;
+ struct ipcomp_data *ipcd;
+ struct xfrm_algo_desc *calg_desc;
+
+ err = -EINVAL;
+ if (!x->calg)
+ goto out;
+
+ if (x->encap)
+ goto out;
+
+ err = -ENOMEM;
+ ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
+ if (!ipcd)
+ goto out;
+
+ mutex_lock(&ipcomp_resource_mutex);
+ if (!ipcomp_alloc_scratches())
+ goto error;
+
+ ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
+ if (!ipcd->tfms)
+ goto error;
+ mutex_unlock(&ipcomp_resource_mutex);
+
+ calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
+ BUG_ON(!calg_desc);
+ ipcd->threshold = calg_desc->uinfo.comp.threshold;
+ x->data = ipcd;
+ err = 0;
+out:
+ return err;
+
+error:
+ ipcomp_free_data(ipcd);
+ mutex_unlock(&ipcomp_resource_mutex);
+ kfree(ipcd);
+ goto out;
+}
+EXPORT_SYMBOL_GPL(ipcomp_init_state);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
+MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
projects / kernel / kernel-generic.git / commitdiff