On Mon, 2013-01-28 at 12:55 +0100, Johannes Berg wrote:
> 2) I'm making userspace configure the source port, and while some
> special cases might want this it seems like normally the kernel
> should pick an unused port. Does it seem acceptable to create a
> socket at configuration time, use inet_csk_get_port() to get an
> unused port and hang on to it until the configuration is removed
> again some time later (after suspend/resume)?
Ok so let's get the question down to something technical -- Does the
below seem like a reasonable use of the socket APIs?
johannes
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -19,6 +19,7 @@
#include <net/genetlink.h>
#include <net/cfg80211.h>
#include <net/sock.h>
+#include <net/inet_connection_sock.h>
#include "core.h"
#include "nl80211.h"
#include "reg.h"
@@ -7104,7 +7105,6 @@ static int nl80211_parse_wowlan_tcp(struct cfg80211_registered_device *rdev,
if (!tb[NL80211_WOWLAN_TCP_SRC_IPV4] ||
!tb[NL80211_WOWLAN_TCP_DST_IPV4] ||
!tb[NL80211_WOWLAN_TCP_DST_MAC] ||
- !tb[NL80211_WOWLAN_TCP_SRC_PORT] ||
!tb[NL80211_WOWLAN_TCP_DST_PORT] ||
!tb[NL80211_WOWLAN_TCP_DATA_PAYLOAD] ||
!tb[NL80211_WOWLAN_TCP_DATA_INTERVAL] ||
@@ -7170,7 +7170,24 @@ static int nl80211_parse_wowlan_tcp(struct cfg80211_registered_device *rdev,
cfg->dst = nla_get_be32(tb[NL80211_WOWLAN_TCP_DST_IPV4]);
memcpy(cfg->dst_mac, nla_data(tb[NL80211_WOWLAN_TCP_DST_MAC]),
ETH_ALEN);
- cfg->src_port = nla_get_u16(tb[NL80211_WOWLAN_TCP_SRC_PORT]);
+ if (tb[NL80211_WOWLAN_TCP_SRC_PORT]) {
+ cfg->src_port = nla_get_u16(tb[NL80211_WOWLAN_TCP_SRC_PORT]);
+ } else {
+ /* allocate a socket and port for it and use it */
+ err = __sock_create(wiphy_net(&rdev->wiphy), PF_INET, SOCK_STREAM,
+ IPPROTO_TCP, &cfg->sock, 1);
+ if (err) {
+ kfree(cfg);
+ return err;
+ }
+ if (inet_csk_get_port(cfg->sock->sk, 0)) {
+ sock_release(cfg->sock);
+ kfree(cfg);
+ return -ENOSPC;
+ }
+ cfg->src_port = inet_sk(cfg->sock->sk)->inet_num;
+ printk(KERN_DEBUG "allocated socket with port %d\n", cfg->src_port);
+ }
cfg->dst_port = nla_get_u16(tb[NL80211_WOWLAN_TCP_DST_PORT]);
cfg->payload_len = data_size;
cfg->payload = (u8 *)cfg + sizeof(*cfg) + tokens_size;
@@ -7354,6 +7371,8 @@ static int nl80211_set_wowlan(struct sk_buff *skb, struct genl_info *info)
for (i = 0; i < new_triggers.n_patterns; i++)
kfree(new_triggers.patterns[i].mask);
kfree(new_triggers.patterns);
+ if (new_triggers.tcp && new_triggers.tcp->sock)
+ sock_release(new_triggers.tcp->sock);
kfree(new_triggers.tcp);
return err;
}
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -19,6 +19,7 @@
#include <linux/nl80211.h>
#include <linux/if_ether.h>
#include <linux/ieee80211.h>
+#include <linux/net.h>
#include <net/regulatory.h>
/**
@@ -1576,6 +1577,7 @@ struct cfg80211_wowlan_trig_pkt_pattern {
/**
* struct cfg80211_wowlan_tcp - TCP connection parameters
*
+ * @sk: (internal) port allocated if source port was automatically selected
* @src: source IP address
* @dst: destination IP address
* @dst_mac: destination MAC address
@@ -1592,6 +1594,7 @@ struct cfg80211_wowlan_trig_pkt_pattern {
* @payload_tok: payload token usage configuration
*/
struct cfg80211_wowlan_tcp {
+ struct socket *sock;
__be32 src, dst;
u16 src_port, dst_port;
u8 dst_mac[ETH_ALEN];
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -3092,7 +3092,8 @@ struct nl80211_wowlan_tcp_data_token_feature {
* route lookup when configured might be invalid by the time we suspend,
* and doing a route lookup when suspending is no longer possible as it
* might require ARP querying.
- * @NL80211_WOWLAN_TCP_SRC_PORT: source port (u16)
+ * @NL80211_WOWLAN_TCP_SRC_PORT: source port (u16); optional, if not given a
+ * socket and port will be allocated
* @NL80211_WOWLAN_TCP_DST_PORT: destination port (u16)
* @NL80211_WOWLAN_TCP_DATA_PAYLOAD: data packet payload, at least one byte.
* For feature advertising, a u32 attribute holding the maximum length
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -109,6 +109,8 @@ cfg80211_rdev_free_wowlan(struct cfg80211_registered_device *rdev)
for (i = 0; i < rdev->wowlan->n_patterns; i++)
kfree(rdev->wowlan->patterns[i].mask);
kfree(rdev->wowlan->patterns);
+ if (rdev->wowlan->tcp && rdev->wowlan->tcp->sock)
+ sock_release(rdev->wowlan->tcp->sock);
kfree(rdev->wowlan->tcp);
kfree(rdev->wowlan);
}
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