ipsec: ipcomp - Merge IPComp implementations

This patch merges the IPv4/IPv6 IPComp implementations since most
of the code is identical.  As a result future enhancements will no
longer need to be duplicated.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 8 insertions, 311 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 4670683b4688..591ea23639ca 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -356,10 +356,8 @@ config INET_ESP
 
 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.
diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index a75807b971b3..a42b64d040c4 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -14,153 +14,14 @@
  *   - 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)
 {
@@ -241,156 +102,12 @@ out:
         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:
@@ -402,40 +119,22 @@ static int ipcomp_init_state(struct xfrm_state *x)
                 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;
 }
 
@@ -443,7 +142,7 @@ static const struct xfrm_type ipcomp_type = {
         .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
@@ -481,7 +180,7 @@ module_init(ipcomp4_init);
 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);