From 9a4595bc7e67962f13232ee55a64e063062c3a99 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 15 Aug 2005 12:32:15 -0700 Subject: [NETLINK]: Add set/getsockopt options to support more than 32 groups NETLINK_ADD_MEMBERSHIP/NETLINK_DROP_MEMBERSHIP are used to join/leave groups, NETLINK_PKTINFO is used to enable nl_pktinfo control messages for received packets to get the extended destination group number. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/netlink.h | 9 +++++ include/linux/socket.h | 1 + net/netlink/af_netlink.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 103 insertions(+), 2 deletions(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index c724c9d4984..36a40449f9f 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -90,6 +90,15 @@ struct nlmsgerr struct nlmsghdr msg; }; +#define NETLINK_ADD_MEMBERSHIP 1 +#define NETLINK_DROP_MEMBERSHIP 2 +#define NETLINK_PKTINFO 3 + +struct nl_pktinfo +{ + __u32 group; +}; + #define NET_MAJOR 36 /* Major 36 is reserved for networking */ enum { diff --git a/include/linux/socket.h b/include/linux/socket.h index ddf22559f48..acc55aac8a4 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -272,6 +272,7 @@ struct ucred { #define SOL_NETBEUI 267 #define SOL_LLC 268 #define SOL_DCCP 269 +#define SOL_NETLINK 270 /* IPX options */ #define IPX_TYPE 1 diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 58d4ca42ac3..47e79173801 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -81,6 +81,7 @@ struct netlink_sock { }; #define NETLINK_KERNEL_SOCKET 0x1 +#define NETLINK_RECV_PKTINFO 0x2 static inline struct netlink_sock *nlk_sk(struct sock *sk) { @@ -946,6 +947,94 @@ void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) read_unlock(&nl_table_lock); } +static int netlink_setsockopt(struct socket *sock, int level, int optname, + char __user *optval, int optlen) +{ + struct sock *sk = sock->sk; + struct netlink_sock *nlk = nlk_sk(sk); + int val = 0, err; + + if (level != SOL_NETLINK) + return -ENOPROTOOPT; + + if (optlen >= sizeof(int) && + get_user(val, (int __user *)optval)) + return -EFAULT; + + switch (optname) { + case NETLINK_PKTINFO: + if (val) + nlk->flags |= NETLINK_RECV_PKTINFO; + else + nlk->flags &= ~NETLINK_RECV_PKTINFO; + err = 0; + break; + case NETLINK_ADD_MEMBERSHIP: + case NETLINK_DROP_MEMBERSHIP: { + unsigned int subscriptions; + int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0; + + if (!netlink_capable(sock, NL_NONROOT_RECV)) + return -EPERM; + if (!val || val - 1 >= nlk->ngroups) + return -EINVAL; + netlink_table_grab(); + old = test_bit(val - 1, nlk->groups); + subscriptions = nlk->subscriptions - old + new; + if (new) + __set_bit(val - 1, nlk->groups); + else + __clear_bit(val - 1, nlk->groups); + netlink_update_subscriptions(sk, subscriptions); + netlink_table_ungrab(); + err = 0; + break; + } + default: + err = -ENOPROTOOPT; + } + return err; +} + +static int netlink_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct sock *sk = sock->sk; + struct netlink_sock *nlk = nlk_sk(sk); + int len, val, err; + + if (level != SOL_NETLINK) + return -ENOPROTOOPT; + + if (get_user(len, optlen)) + return -EFAULT; + if (len < 0) + return -EINVAL; + + switch (optname) { + case NETLINK_PKTINFO: + if (len < sizeof(int)) + return -EINVAL; + len = sizeof(int); + val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; + put_user(len, optlen); + put_user(val, optval); + err = 0; + break; + default: + err = -ENOPROTOOPT; + } + return err; +} + +static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) +{ + struct nl_pktinfo info; + + info.group = NETLINK_CB(skb).dst_group; + put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); +} + static inline void netlink_rcv_wake(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); @@ -1091,6 +1180,8 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, netlink_dump(sk); scm_recv(sock, msg, siocb->scm, flags); + if (nlk->flags & NETLINK_RECV_PKTINFO) + netlink_cmsg_recv_pktinfo(msg, skb); out: netlink_rcv_wake(sk); @@ -1465,8 +1556,8 @@ static struct proto_ops netlink_ops = { .ioctl = sock_no_ioctl, .listen = sock_no_listen, .shutdown = sock_no_shutdown, - .setsockopt = sock_no_setsockopt, - .getsockopt = sock_no_getsockopt, + .setsockopt = netlink_setsockopt, + .getsockopt = netlink_getsockopt, .sendmsg = netlink_sendmsg, .recvmsg = netlink_recvmsg, .mmap = sock_no_mmap, -- cgit v1.2.3