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-rw-r--r--net/Kconfig20
-rw-r--r--net/compat.c17
-rw-r--r--net/netlink/af_netlink.c36
-rw-r--r--net/wireless/wext.c78
4 files changed, 148 insertions, 3 deletions
diff --git a/net/Kconfig b/net/Kconfig
index 7051b971067..041c35edb76 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -23,6 +23,26 @@ menuconfig NET
if NET
+config WANT_COMPAT_NETLINK_MESSAGES
+ bool
+ help
+ This option can be selected by other options that need compat
+ netlink messages.
+
+config COMPAT_NETLINK_MESSAGES
+ def_bool y
+ depends on COMPAT
+ depends on WIRELESS_EXT || WANT_COMPAT_NETLINK_MESSAGES
+ help
+ This option makes it possible to send different netlink messages
+ to tasks depending on whether the task is a compat task or not. To
+ achieve this, you need to set skb_shinfo(skb)->frag_list to the
+ compat skb before sending the skb, the netlink code will sort out
+ which message to actually pass to the task.
+
+ Newly written code should NEVER need this option but do
+ compat-independent messages instead!
+
menu "Networking options"
source "net/packet/Kconfig"
diff --git a/net/compat.c b/net/compat.c
index 8d739053afe..12728b17a22 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -743,6 +743,18 @@ asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, uns
return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}
+asmlinkage long compat_sys_recv(int fd, void __user *buf, size_t len, unsigned flags)
+{
+ return sys_recv(fd, buf, len, flags | MSG_CMSG_COMPAT);
+}
+
+asmlinkage long compat_sys_recvfrom(int fd, void __user *buf, size_t len,
+ unsigned flags, struct sockaddr __user *addr,
+ int __user *addrlen)
+{
+ return sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr, addrlen);
+}
+
asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
{
int ret;
@@ -788,10 +800,11 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
ret = sys_sendto(a0, compat_ptr(a1), a[2], a[3], compat_ptr(a[4]), a[5]);
break;
case SYS_RECV:
- ret = sys_recv(a0, compat_ptr(a1), a[2], a[3]);
+ ret = compat_sys_recv(a0, compat_ptr(a1), a[2], a[3]);
break;
case SYS_RECVFROM:
- ret = sys_recvfrom(a0, compat_ptr(a1), a[2], a[3], compat_ptr(a[4]), compat_ptr(a[5]));
+ ret = compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
+ compat_ptr(a[4]), compat_ptr(a[5]));
break;
case SYS_SHUTDOWN:
ret = sys_shutdown(a0,a1);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index d46da6cb92e..da3163d15ef 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1361,7 +1361,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
struct netlink_sock *nlk = nlk_sk(sk);
int noblock = flags&MSG_DONTWAIT;
size_t copied;
- struct sk_buff *skb;
+ struct sk_buff *skb, *frag __maybe_unused = NULL;
int err;
if (flags&MSG_OOB)
@@ -1373,6 +1373,35 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
if (skb == NULL)
goto out;
+#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
+ if (unlikely(skb_shinfo(skb)->frag_list)) {
+ bool need_compat = !!(flags & MSG_CMSG_COMPAT);
+
+ /*
+ * If this skb has a frag_list, then here that means that
+ * we will have to use the frag_list skb for compat tasks
+ * and the regular skb for non-compat tasks.
+ *
+ * The skb might (and likely will) be cloned, so we can't
+ * just reset frag_list and go on with things -- we need to
+ * keep that. For the compat case that's easy -- simply get
+ * a reference to the compat skb and free the regular one
+ * including the frag. For the non-compat case, we need to
+ * avoid sending the frag to the user -- so assign NULL but
+ * restore it below before freeing the skb.
+ */
+ if (need_compat) {
+ struct sk_buff *compskb = skb_shinfo(skb)->frag_list;
+ skb_get(compskb);
+ kfree_skb(skb);
+ skb = compskb;
+ } else {
+ frag = skb_shinfo(skb)->frag_list;
+ skb_shinfo(skb)->frag_list = NULL;
+ }
+ }
+#endif
+
msg->msg_namelen = 0;
copied = skb->len;
@@ -1403,6 +1432,11 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
siocb->scm->creds = *NETLINK_CREDS(skb);
if (flags & MSG_TRUNC)
copied = skb->len;
+
+#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
+ skb_shinfo(skb)->frag_list = frag;
+#endif
+
skb_free_datagram(sk, skb);
if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
diff --git a/net/wireless/wext.c b/net/wireless/wext.c
index ee35e6422f1..3fe3c2c0ce1 100644
--- a/net/wireless/wext.c
+++ b/net/wireless/wext.c
@@ -417,6 +417,21 @@ static const int event_type_size[] = {
IW_EV_QUAL_LEN, /* IW_HEADER_TYPE_QUAL */
};
+#ifdef CONFIG_COMPAT
+static const int compat_event_type_size[] = {
+ IW_EV_COMPAT_LCP_LEN, /* IW_HEADER_TYPE_NULL */
+ 0,
+ IW_EV_COMPAT_CHAR_LEN, /* IW_HEADER_TYPE_CHAR */
+ 0,
+ IW_EV_COMPAT_UINT_LEN, /* IW_HEADER_TYPE_UINT */
+ IW_EV_COMPAT_FREQ_LEN, /* IW_HEADER_TYPE_FREQ */
+ IW_EV_COMPAT_ADDR_LEN, /* IW_HEADER_TYPE_ADDR */
+ 0,
+ IW_EV_COMPAT_POINT_LEN, /* Without variable payload */
+ IW_EV_COMPAT_PARAM_LEN, /* IW_HEADER_TYPE_PARAM */
+ IW_EV_COMPAT_QUAL_LEN, /* IW_HEADER_TYPE_QUAL */
+};
+#endif
/************************ COMMON SUBROUTINES ************************/
/*
@@ -1348,6 +1363,22 @@ void wireless_send_event(struct net_device * dev,
struct sk_buff *skb;
struct nlmsghdr *nlh;
struct nlattr *nla;
+#ifdef CONFIG_COMPAT
+ struct __compat_iw_event *compat_event;
+ struct compat_iw_point compat_wrqu;
+ struct sk_buff *compskb;
+#endif
+
+ /*
+ * Nothing in the kernel sends scan events with data, be safe.
+ * This is necessary because we cannot fix up scan event data
+ * for compat, due to being contained in 'extra', but normally
+ * applications are required to retrieve the scan data anyway
+ * and no data is included in the event, this codifies that
+ * practice.
+ */
+ if (WARN_ON(cmd == SIOCGIWSCAN && extra))
+ extra = NULL;
/* Get the description of the Event */
if (cmd <= SIOCIWLAST) {
@@ -1446,7 +1477,54 @@ void wireless_send_event(struct net_device * dev,
memcpy(((char *) event) + hdr_len, extra, extra_len);
nlmsg_end(skb, nlh);
+#ifdef CONFIG_COMPAT
+ hdr_len = compat_event_type_size[descr->header_type];
+ event_len = hdr_len + extra_len;
+ compskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+ if (!compskb) {
+ kfree_skb(skb);
+ return;
+ }
+
+ /* Send via the RtNetlink event channel */
+ nlh = rtnetlink_ifinfo_prep(dev, compskb);
+ if (WARN_ON(!nlh)) {
+ kfree_skb(skb);
+ kfree_skb(compskb);
+ return;
+ }
+
+ /* Add the wireless events in the netlink packet */
+ nla = nla_reserve(compskb, IFLA_WIRELESS, event_len);
+ if (!nla) {
+ kfree_skb(skb);
+ kfree_skb(compskb);
+ return;
+ }
+ compat_event = nla_data(nla);
+
+ compat_event->len = event_len;
+ compat_event->cmd = cmd;
+ if (descr->header_type == IW_HEADER_TYPE_POINT) {
+ compat_wrqu.length = wrqu->data.length;
+ compat_wrqu.flags = wrqu->data.flags;
+ memcpy(&compat_event->pointer,
+ ((char *) &compat_wrqu) + IW_EV_COMPAT_POINT_OFF,
+ hdr_len - IW_EV_COMPAT_LCP_LEN);
+ if (extra_len)
+ memcpy(((char *) compat_event) + hdr_len,
+ extra, extra_len);
+ } else {
+ /* extra_len must be zero, so no if (extra) needed */
+ memcpy(&compat_event->pointer, wrqu,
+ hdr_len - IW_EV_COMPAT_LCP_LEN);
+ }
+
+ nlmsg_end(compskb, nlh);
+
+ skb_shinfo(skb)->frag_list = compskb;
+#endif
skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
schedule_work(&wireless_nlevent_work);
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-03 22:49:59 +0000