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[NETLINK]: Use group numbers instead of bitmasks internally

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Using the group number allows increasing the number of groups without
beeing limited by the size of the bitmask. It introduces one limitation
for netlink users: messages can't be broadcasted to multiple groups anymore,
however this feature was never used inside the kernel.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2005-08-14 19:27:50 -07:00 committed by David S. Miller
parent 77247bbb30
commit d629b836d1
2 changed files with 21 additions and 16 deletions
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2
include/linux/netlink.h
View file

@ -107,7 +107,7 @@ struct netlink_skb_parms
struct ucred creds; /* Skb credentials */
__u32 pid;
__u32 dst_pid;
__u32 dst_groups;
__u32 dst_group;
kernel_cap_t eff_cap;
__u32 loginuid; /* Login (audit) uid */
};

35
net/netlink/af_netlink.c
View file

@ -67,7 +67,7 @@ struct netlink_sock {
u32 pid;
unsigned int groups;
u32 dst_pid;
unsigned int dst_groups;
u32 dst_group;
unsigned long state;
wait_queue_head_t wait;
struct netlink_callback *cb;
@ -116,6 +116,11 @@ static atomic_t nl_table_users = ATOMIC_INIT(0);
static struct notifier_block *netlink_chain;
static u32 netlink_group_mask(u32 group)
{
return group ? 1 << (group - 1) : 0;
}
static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
{
return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
@ -533,7 +538,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
if (addr->sa_family == AF_UNSPEC) {
sk->sk_state = NETLINK_UNCONNECTED;
nlk->dst_pid = 0;
nlk->dst_groups = 0;
nlk->dst_group = 0;
return 0;
}
if (addr->sa_family != AF_NETLINK)
@ -549,7 +554,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
if (err == 0) {
sk->sk_state = NETLINK_CONNECTED;
nlk->dst_pid = nladdr->nl_pid;
nlk->dst_groups = nladdr->nl_groups;
nlk->dst_group = ffs(nladdr->nl_groups);
}
return err;
@ -567,10 +572,10 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr
if (peer) {
nladdr->nl_pid = nlk->dst_pid;
nladdr->nl_groups = nlk->dst_groups;
nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
} else {
nladdr->nl_pid = nlk->pid;
nladdr->nl_groups = nlk->groups;
nladdr->nl_groups = nlk->groups;
}
return 0;
}
@ -771,7 +776,7 @@ static inline int do_one_broadcast(struct sock *sk,
if (p->exclude_sk == sk)
goto out;
if (nlk->pid == p->pid || !(nlk->groups & p->group))
if (nlk->pid == p->pid || !(nlk->groups & netlink_group_mask(p->group)))
goto out;
if (p->failure) {
@ -867,7 +872,7 @@ static inline int do_one_set_err(struct sock *sk,
if (sk == p->exclude_sk)
goto out;
if (nlk->pid == p->pid || !(nlk->groups & p->group))
if (nlk->pid == p->pid || !(nlk->groups & netlink_group_mask(p->group)))
goto out;
sk->sk_err = p->code;
@ -913,7 +918,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct netlink_sock *nlk = nlk_sk(sk);
struct sockaddr_nl *addr=msg->msg_name;
u32 dst_pid;
u32 dst_groups;
u32 dst_group;
struct sk_buff *skb;
int err;
struct scm_cookie scm;
@ -931,12 +936,12 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
if (addr->nl_family != AF_NETLINK)
return -EINVAL;
dst_pid = addr->nl_pid;
dst_groups = addr->nl_groups;
if (dst_groups && !netlink_capable(sock, NL_NONROOT_SEND))
dst_group = ffs(addr->nl_groups);
if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
return -EPERM;
} else {
dst_pid = nlk->dst_pid;
dst_groups = nlk->dst_groups;
dst_group = nlk->dst_group;
}
if (!nlk->pid) {
@ -955,7 +960,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
NETLINK_CB(skb).pid = nlk->pid;
NETLINK_CB(skb).dst_pid = dst_pid;
NETLINK_CB(skb).dst_groups = dst_groups;
NETLINK_CB(skb).dst_group = dst_group;
NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context);
memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
@ -977,9 +982,9 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
goto out;
}
if (dst_groups) {
if (dst_group) {
atomic_inc(&skb->users);
netlink_broadcast(sk, skb, dst_pid, dst_groups, GFP_KERNEL);
netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
}
err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
@ -1025,7 +1030,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
addr->nl_family = AF_NETLINK;
addr->nl_pad = 0;
addr->nl_pid = NETLINK_CB(skb).pid;
addr->nl_groups = NETLINK_CB(skb).dst_groups;
addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
msg->msg_namelen = sizeof(*addr);
}