diff options
author | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-27 12:25:57 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-07-27 12:25:57 -0300 |
commit | 50cb993ea6cd187bfed085cb3e0747066edeb02f (patch) | |
tree | 61edac62c6c5bc07c59e4369c50c6821ad77f2c0 /net/xfrm/xfrm_ipcomp.c | |
parent | 445c2714cf72817ab1ad3ca894c6d9b2047b3a3e (diff) | |
parent | 8be1a6d6c77ab4532e4476fdb8177030ef48b52c (diff) |
Merge ../linux-2.6
Diffstat (limited to 'net/xfrm/xfrm_ipcomp.c')
-rw-r--r-- | net/xfrm/xfrm_ipcomp.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c new file mode 100644 index 00000000000..c609a4b98e1 --- /dev/null +++ b/net/xfrm/xfrm_ipcomp.c @@ -0,0 +1,384 @@ +/* + * 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/gfp.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/percpu.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); + int len; + + if (err) + goto out; + + if (dlen < (plen + sizeof(struct ip_comp_hdr))) { + err = -EINVAL; + goto out; + } + + len = dlen - plen; + if (len > skb_tailroom(skb)) + len = skb_tailroom(skb); + + skb->truesize += len; + __skb_put(skb, len); + + len += plen; + skb_copy_to_linear_data(skb, scratch, len); + + while ((scratch += len, dlen -= len) > 0) { + skb_frag_t *frag; + + err = -EMSGSIZE; + if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) + goto out; + + frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags; + frag->page = alloc_page(GFP_ATOMIC); + + err = -ENOMEM; + if (!frag->page) + goto out; + + len = PAGE_SIZE; + if (dlen < len) + len = dlen; + + memcpy(page_address(frag->page), scratch, len); + + frag->page_offset = 0; + frag->size = len; + skb->truesize += len; + skb->data_len += len; + skb->len += len; + + skb_shinfo(skb)->nr_frags++; + } + + err = 0; + +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; + } + + WARN_ON(!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>"); 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