From: "Eric W. Biederman" <ebiederm@xmission.com>
To: David Miller <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>,
netfilter-devel@vger.kernel.org,
Stephen Hemminger <stephen@networkplumber.org>,
Juanjo Ciarlante <jjciarla@raiz.uncu.edu.ar>,
Wensong Zhang <wensong@linux-vs.org>,
Simon Horman <horms@verge.net.au>, Julian Anastasov <ja@ssi.bg>,
Pablo Neira Ayuso <pablo@netfilter.org>,
Patrick McHardy <kaber@trash.net>,
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
Jamal Hadi Salim <jhs@mojatatu.com>,
Steffen Klassert <steffen.klassert@secunet.com>,
Herbert Xu <herbert@gondor.apana.org.au>
Subject: [PATCH net-next 25/43] netfilter: Make nf_hook_ops just a parameter structure
Date: Wed, 17 Jun 2015 10:28:34 -0500 [thread overview]
Message-ID: <1434554932-4552-25-git-send-email-ebiederm@xmission.com> (raw)
In-Reply-To: <87r3pae5hn.fsf@x220.int.ebiederm.org>
From: Eric W Biederman <ebiederm@xmission.com>
Add a new structure nf_hook_entry that makes up the nf_hook_lists, and
dynamically allocate it nf_register_hook and free it in
nf_unregister_hook.
This gives the netfilter hook code a little more freedom to evolve
and removes an error case when converting netfilter hooks to be
per nework namespace.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
include/linux/netfilter.h | 12 +++---
include/net/netfilter/nf_queue.h | 4 +-
net/netfilter/core.c | 92 +++++++++++++++++++++++++---------------
net/netfilter/nf_internals.h | 13 +++++-
net/netfilter/nf_queue.c | 6 +--
5 files changed, 80 insertions(+), 47 deletions(-)
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 43db9eaf42f6..054cd9d45324 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -84,8 +84,6 @@ typedef unsigned int nf_hookfn(void *priv,
const struct nf_hook_state *state);
struct nf_hook_ops {
- struct list_head list;
-
/* User fills in from here down. */
nf_hookfn *hook;
struct net_device *dev;
@@ -122,10 +120,12 @@ struct nf_sockopt_ops {
};
/* Function to register/unregister hook points. */
-int nf_register_hook(struct net *net, struct nf_hook_ops *reg);
-void nf_unregister_hook(struct net *net, struct nf_hook_ops *reg);
-int nf_register_hooks(struct net *net, struct nf_hook_ops *reg, unsigned int n);
-void nf_unregister_hooks(struct net *net, struct nf_hook_ops *reg, unsigned int n);
+int nf_register_hook(struct net *net, const struct nf_hook_ops *reg);
+void nf_unregister_hook(struct net *net, const struct nf_hook_ops *reg);
+int nf_register_hooks(struct net *net, const struct nf_hook_ops *reg,
+ unsigned int n);
+void nf_unregister_hooks(struct net *net, const struct nf_hook_ops *reg,
+ unsigned int n);
/* Functions to register get/setsockopt ranges (non-inclusive). You
need to check permissions yourself! */
diff --git a/include/net/netfilter/nf_queue.h b/include/net/netfilter/nf_queue.h
index d81d584157e1..cad00472e3be 100644
--- a/include/net/netfilter/nf_queue.h
+++ b/include/net/netfilter/nf_queue.h
@@ -5,13 +5,15 @@
#include <linux/ipv6.h>
#include <linux/jhash.h>
+struct nf_hook_entry;
+
/* Each queued (to userspace) skbuff has one of these. */
struct nf_queue_entry {
struct list_head list;
struct sk_buff *skb;
unsigned int id;
- struct nf_hook_ops *elem;
+ struct nf_hook_entry *elem;
struct nf_hook_state state;
u16 size; /* sizeof(entry) + saved route keys */
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index ccf248607342..95456c09cf69 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -59,34 +59,46 @@ EXPORT_SYMBOL(nf_hooks_needed);
static DEFINE_MUTEX(nf_hook_mutex);
-int nf_register_hook(struct net *net, struct nf_hook_ops *reg)
+static struct list_head *find_nf_hook_list(struct net *net,
+ const struct nf_hook_ops *reg)
{
struct list_head *nf_hook_list;
- struct nf_hook_ops *elem;
- mutex_lock(&nf_hook_mutex);
- switch (reg->pf) {
- case NFPROTO_NETDEV:
+ nf_hook_list = &net->nf.hooks[reg->pf][reg->hooknum];
#ifdef CONFIG_NETFILTER_INGRESS
- if (reg->hooknum == NF_NETDEV_INGRESS) {
- BUG_ON(reg->dev == NULL);
- nf_hook_list = ®->dev->nf_hooks_ingress;
- net_inc_ingress_queue();
- break;
- }
+ if ((reg->pf == NFPROTO_NETDEV) && (reg->hooknum == NF_NETDEV_INGRESS))
+ nf_hook_list = ®->dev->nf_hooks_ingress;
#endif
- /* Fall through. */
- default:
- nf_hook_list = &net->nf.hooks[reg->pf][reg->hooknum];
- break;
- }
+ return nf_hook_list;
+}
+int nf_register_hook(struct net *net, const struct nf_hook_ops *reg)
+{
+ struct list_head *nf_hook_list;
+ struct nf_hook_entry *elem, *new;
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+
+ new->hook = reg->hook;
+ new->priv = reg->priv;
+ new->owner = reg->owner;
+ new->priority = reg->priority;
+
+ mutex_lock(&nf_hook_mutex);
+ nf_hook_list = find_nf_hook_list(net, reg);
list_for_each_entry(elem, nf_hook_list, list) {
- if (reg->priority < elem->priority)
+ if (new->priority < elem->priority)
break;
}
- list_add_rcu(®->list, elem->list.prev);
+ list_add_rcu(&new->list, elem->list.prev);
mutex_unlock(&nf_hook_mutex);
+
+#ifdef CONFIG_NETFILTER_INGRESS
+ if ((reg->pf == NFPROTO_NETDEV) && (reg->hooknum == NF_NETDEV_INGRESS))
+ net_inc_ingress_queue();
+#endif
#ifdef HAVE_JUMP_LABEL
static_key_slow_inc(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
@@ -94,31 +106,41 @@ int nf_register_hook(struct net *net, struct nf_hook_ops *reg)
}
EXPORT_SYMBOL(nf_register_hook);
-void nf_unregister_hook(struct net *net, struct nf_hook_ops *reg)
+void nf_unregister_hook(struct net *net, const struct nf_hook_ops *reg)
{
+ struct list_head *nf_hook_list;
+ struct nf_hook_entry *elem;
+
mutex_lock(&nf_hook_mutex);
- list_del_rcu(®->list);
- mutex_unlock(&nf_hook_mutex);
- switch (reg->pf) {
- case NFPROTO_NETDEV:
-#ifdef CONFIG_NETFILTER_INGRESS
- if (reg->hooknum == NF_NETDEV_INGRESS) {
- net_dec_ingress_queue();
+ nf_hook_list = find_nf_hook_list(net, reg);
+ list_for_each_entry(elem, nf_hook_list, list) {
+ if ((reg->hook == elem->hook) &&
+ (reg->priv == elem->priv) &&
+ (reg->owner == elem->owner) &&
+ (reg->priority == elem->priority)) {
+ list_del_rcu(&elem->list);
break;
}
- break;
-#endif
- default:
- break;
}
+ mutex_unlock(&nf_hook_mutex);
+ if (&elem->list == nf_hook_list) {
+ WARN(1, "nf_unregister_hook: hook not found!\n");
+ return;
+ }
+#ifdef CONFIG_NETFILTER_INGRESS
+ if ((reg->pf == NFPROTO_NETDEV) && (reg->hooknum == NF_NETDEV_INGRESS))
+ net_dec_ingress_queue();
+#endif
#ifdef HAVE_JUMP_LABEL
static_key_slow_dec(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
synchronize_net();
+ kfree(elem);
}
EXPORT_SYMBOL(nf_unregister_hook);
-int nf_register_hooks(struct net *net, struct nf_hook_ops *reg, unsigned int n)
+int nf_register_hooks(struct net *net, const struct nf_hook_ops *reg,
+ unsigned int n)
{
unsigned int i;
int err = 0;
@@ -137,7 +159,7 @@ err:
}
EXPORT_SYMBOL(nf_register_hooks);
-void nf_unregister_hooks(struct net *net, struct nf_hook_ops *reg,
+void nf_unregister_hooks(struct net *net, const struct nf_hook_ops *reg,
unsigned int n)
{
while (n-- > 0)
@@ -148,7 +170,7 @@ EXPORT_SYMBOL(nf_unregister_hooks);
unsigned int nf_iterate(struct list_head *head,
struct sk_buff *skb,
struct nf_hook_state *state,
- struct nf_hook_ops **elemp)
+ struct nf_hook_entry **elemp)
{
unsigned int verdict;
@@ -186,14 +208,14 @@ repeat:
* -EPERM for NF_DROP, 0 otherwise. */
int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state)
{
- struct nf_hook_ops *elem;
+ struct nf_hook_entry *elem;
unsigned int verdict;
int ret = 0;
/* We may already have this, but read-locks nest anyway */
rcu_read_lock();
- elem = list_entry_rcu(state->hook_list, struct nf_hook_ops, list);
+ elem = list_entry_rcu(state->hook_list, struct nf_hook_entry, list);
next_hook:
verdict = nf_iterate(state->hook_list, skb, state, &elem);
if (verdict == NF_ACCEPT || verdict == NF_STOP) {
diff --git a/net/netfilter/nf_internals.h b/net/netfilter/nf_internals.h
index ea7f36784b3d..ff8e1f7197dc 100644
--- a/net/netfilter/nf_internals.h
+++ b/net/netfilter/nf_internals.h
@@ -13,11 +13,20 @@
/* core.c */
+struct nf_hook_entry {
+ struct list_head list;
+ nf_hookfn *hook;
+ void *priv;
+ struct module *owner;
+ /* Hooks are ordered in ascending priority. */
+ int priority;
+};
+
unsigned int nf_iterate(struct list_head *head, struct sk_buff *skb,
- struct nf_hook_state *state, struct nf_hook_ops **elemp);
+ struct nf_hook_state *state, struct nf_hook_entry **elemp);
/* nf_queue.c */
-int nf_queue(struct sk_buff *skb, struct nf_hook_ops *elem,
+int nf_queue(struct sk_buff *skb, struct nf_hook_entry *elem,
struct nf_hook_state *state, unsigned int queuenum);
int __init netfilter_queue_init(void);
diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index ab077fe4c1b8..6ae3b2ccceb8 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -110,7 +110,7 @@ EXPORT_SYMBOL_GPL(nf_queue_entry_get_refs);
* through nf_reinject().
*/
int nf_queue(struct sk_buff *skb,
- struct nf_hook_ops *elem,
+ struct nf_hook_entry *elem,
struct nf_hook_state *state,
unsigned int queuenum)
{
@@ -172,7 +172,7 @@ err:
void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
{
struct sk_buff *skb = entry->skb;
- struct nf_hook_ops *elem = entry->elem;
+ struct nf_hook_entry *elem = entry->elem;
const struct nf_afinfo *afinfo;
int err;
@@ -182,7 +182,7 @@ void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
/* Continue traversal iff userspace said ok... */
if (verdict == NF_REPEAT) {
- elem = list_entry(elem->list.prev, struct nf_hook_ops, list);
+ elem = list_entry(elem->list.prev, struct nf_hook_entry, list);
verdict = NF_ACCEPT;
}
--
2.2.1
next prev parent reply other threads:[~2015-06-17 15:28 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-15 3:07 [PATCH net-next 00/15] Simplify netfilter and network namespaces Eric W. Biederman
2015-06-15 3:12 ` [PATCH net-next 01/15] netfilter: Kill unused copies of RCV_SKB_FAIL Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 02/15] netfilter: Pass struct net into the netfilter hooks Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 03/15] netfilter: Use nf_hook_state.net Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 04/15] ebtables: Simplify the arguments to ebt_do_table Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 05/15] inet netfilter: Remove hook from ip6t_do_table, arp_do_table, ipt_do_table Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 06/15] inet netfilter: Prefer state->hook to ops->hooknum Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 07/15] nftables: kill nft_pktinfo.ops Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 08/15] tc: Simplify em_ipset_match Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 09/15] x_tables: Pass struct net in xt_action_param Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 10/15] x_tables: Use par->net instead of computing from the passed net devices Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 11/15] nftables: Pass struct net in nft_pktinfo Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 12/15] nf_tables: Use pkt->net instead of computing net from the passed net_devices Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 13/15] nf_conntrack: Add a struct net parameter to l4_pkt_to_tuple Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 14/15] ipv4: Pass struct net into ip_defrag and ip_check_defrag Eric W. Biederman
2015-06-15 3:13 ` [PATCH net-next 15/15] ipv6: Pass struct net into nf_ct_frag6_gather Eric W. Biederman
2015-06-15 7:06 ` [PATCH net-next 00/15] Simplify netfilter and network namespaces Pablo Neira Ayuso
2015-06-15 15:06 ` Eric W. Biederman
2015-06-15 15:20 ` Pablo Neira Ayuso
2015-06-16 0:10 ` David Miller
2015-06-16 0:26 ` Eric W. Biederman
2015-06-16 2:14 ` David Miller
2015-06-16 10:32 ` Pablo Neira Ayuso
2015-06-16 21:00 ` Eric W. Biederman
2015-06-17 15:09 ` [PATCH net-next 00/43] Simplify netfilter and network namespaces (take 2) Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 01/43] netfilter: Kill unused copies of RCV_SKB_FAIL Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 02/43] netfilter: Pass struct net into the netfilter hooks Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 03/43] netfilter: Use nf_hook_state.net Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 04/43] ebtables: Simplify the arguments to ebt_do_table Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 05/43] inet netfilter: Remove hook from ip6t_do_table, arp_do_table, ipt_do_table Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 06/43] inet netfilter: Prefer state->hook to ops->hooknum Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 07/43] nftables: kill nft_pktinfo.ops Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 08/43] tc: Simplify em_ipset_match Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 09/43] x_tables: Pass struct net in xt_action_param Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 10/43] x_tables: Use par->net instead of computing from the passed net devices Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 11/43] nftables: Pass struct net in nft_pktinfo Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 12/43] nf_tables: Use pkt->net instead of computing net from the passed net_devices Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 13/43] nf_conntrack: Add a struct net parameter to l4_pkt_to_tuple Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 14/43] ipv4: Pass struct net into ip_defrag and ip_check_defrag Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 15/43] ipv6: Pass struct net into nf_ct_frag6_gather Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 16/43] net: include missing headers in net/net_namespace.h Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 17/43] netfilter: use forward declaration instead of including linux/proc_fs.h Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 18/43] netfilter: don't pull include/linux/netfilter.h from netns headers Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 19/43] ipvs: Read hooknum from state rather than ops->hooknum Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 20/43] netfilter: Pass priv instead of nf_hook_ops to netfilter hooks Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 21/43] netfilter: Add a network namespace Kconfig conflict Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 22/43] netfilter: Add a struct net parameter to nf_register_hook[s] Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 23/43] netfilter: Add a struct net parameter to nf_unregister_hook[s] Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 24/43] netfilter: Make the netfilter hooks per network namespace Eric W. Biederman
2015-06-17 15:28 ` Eric W. Biederman [this message]
2015-06-17 15:28 ` [PATCH net-next 26/43] netfitler: Remove spurios included of netfilter.h Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 27/43] x_tables: Add magical hook registration in the common case Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 28/43] x_tables: Where possible convert to the new hook registration method Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 29/43] x_tables: Kill xt_[un]hook_link Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 30/43] x_tables: Update ip?table_nat to register their hooks in all network namespaces Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 31/43] netfilter: nf_tables: adapt it to pernet hooks Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 32/43] netfilter: ipt_CLUSTERIP: adapt it to support " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 33/43] netfilter: ebtables: adapt the filter and nat table to " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 34/43] netfilter: bridge: adapt it " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 35/43] ipvs: Register netfilter hooks in all network namespaces Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 36/43] netfilter: nf_conntract: " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 37/43] netfilter: nf_defrag: " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 38/43] netfilter: synproxy: " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 39/43] selinux: adapt it to pernet hooks Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 40/43] smack: " Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 41/43] netfilter: Remove the network namespace Kconfig conflict Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 42/43] netfilter bridge: Make the sysctl knobs per network namespace Eric W. Biederman
2015-06-17 15:28 ` [PATCH net-next 43/43] netfilter: Skip unnecessary calls to synchronize_net Eric W. Biederman
2015-06-17 17:20 ` Patrick McHardy
2015-06-17 20:32 ` Eric W. Biederman
2015-06-18 15:49 ` [PATCH net-next 00/43] Simplify netfilter and network namespaces (take 2) Andreas Schultz
2015-06-18 19:40 ` Pablo Neira Ayuso
2015-07-10 23:11 ` [PATCH -next 0/6] Per network namespace netfilter chains Eric W. Biederman
2015-07-10 23:12 ` [PATCH -next 1/6] netfilter: nf_queue: Don't recompute the hook_list head Eric W. Biederman
2015-07-10 23:13 ` [PATCH -next 2/6] netfilter: kill nf_hooks_active Eric W. Biederman
2015-07-10 23:13 ` [PATCH -next 3/6] netfilter: Simply the tests for enabling and disabling the ingress queue hook Eric W. Biederman
2015-07-10 23:14 ` [PATCH -next 4/6] netfilter: Factor out the hook list selection from nf_register_hook Eric W. Biederman
2015-07-10 23:15 ` [PATCH -next 5/6] netfilter: Per network namespace netfilter hooks Eric W. Biederman
2015-07-15 19:00 ` Pablo Neira Ayuso
2015-07-15 20:22 ` Eric W. Biederman
2015-07-10 23:15 ` [PATCH -next 6/6] netfilter: nftables: Only run the nftables chains in the proper netns Eric W. Biederman
2015-07-15 17:20 ` [PATCH -next 0/6] Per network namespace netfilter chains Pablo Neira Ayuso
2015-07-15 20:05 ` Eric W. Biederman
2015-07-16 11:01 ` Pablo Neira Ayuso
2015-06-17 19:38 ` [PATCH net-next 00/15] Simplify netfilter and network namespaces Julian Anastasov
2015-06-17 20:55 ` Eric W. Biederman
2015-06-17 22:01 ` Julian Anastasov
2015-06-18 14:45 ` Eric W. Biederman
2015-06-18 19:21 ` Julian Anastasov
2015-06-19 14:24 ` Eric W. Biederman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1434554932-4552-25-git-send-email-ebiederm@xmission.com \
--to=ebiederm@xmission.com \
--cc=davem@davemloft.net \
--cc=herbert@gondor.apana.org.au \
--cc=horms@verge.net.au \
--cc=ja@ssi.bg \
--cc=jhs@mojatatu.com \
--cc=jjciarla@raiz.uncu.edu.ar \
--cc=kaber@trash.net \
--cc=kadlec@blackhole.kfki.hu \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=steffen.klassert@secunet.com \
--cc=stephen@networkplumber.org \
--cc=wensong@linux-vs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.