github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-27 17:47:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

netlink: convert to getsockopt_iter

Browse Source 
Convert AF_NETLINK's getsockopt implementation to use the new
getsockopt_iter callback with sockopt_t.

Key changes:
- Replace (char __user *optval, int __user *optlen) with sockopt_t *opt
- Use opt->optlen for buffer length (input) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- For NETLINK_LIST_MEMBERSHIPS: walk the groups bitmap and emit each
  u32 sequentially via copy_to_iter(), then set opt->optlen to the
  total size required (ALIGN(BITS_TO_BYTES(ngroups), sizeof(u32))).
  The wrapper writes opt->optlen back to userspace even on partial
  failure, preserving the existing API that lets userspace discover
  the needed allocation size.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260501-getsock_one-v1-1-810ce23ea70e@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Breno Leitao 2026-05-01 08:52:51 -07:00 committed by Jakub Kicinski
parent 3f3aa77ff1
commit 390bf43b77
1 changed files with 11 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
net/netlink/af_netlink.c
View File

@ -39,6 +39,7 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/uio.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
@ -1716,18 +1717,18 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
}
static int netlink_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
sockopt_t *opt)
{
struct sock *sk = sock->sk;
struct netlink_sock *nlk = nlk_sk(sk);
unsigned int flag;
int len, val;
u32 group;
if (level != SOL_NETLINK)
return -ENOPROTOOPT;
if (get_user(len, optlen))
return -EFAULT;
len = opt->optlen;
if (len < 0)
return -EINVAL;
@ -1751,14 +1752,14 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
idx = pos / sizeof(unsigned long);
shift = (pos % sizeof(unsigned long)) * 8;
if (put_user((u32)(nlk->groups[idx] >> shift),
(u32 __user *)(optval + pos))) {
group = (u32)(nlk->groups[idx] >> shift);
if (copy_to_iter(&group, sizeof(u32),
&opt->iter_out) != sizeof(u32)) {
err = -EFAULT;
break;
}
}
if (put_user(ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)), optlen))
err = -EFAULT;
opt->optlen = ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32));
netlink_unlock_table();
return err;
}
@ -1784,8 +1785,8 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
len = sizeof(int);
val = test_bit(flag, &nlk->flags);
if (put_user(len, optlen) ||
copy_to_user(optval, &val, len))
opt->optlen = len;
if (copy_to_iter(&val, len, &opt->iter_out) != len)
return -EFAULT;
return 0;
@ -2813,7 +2814,7 @@ static const struct proto_ops netlink_ops = {
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = netlink_setsockopt,
.getsockopt = netlink_getsockopt,
.getsockopt_iter = netlink_getsockopt,
.sendmsg = netlink_sendmsg,
.recvmsg = netlink_recvmsg,
.mmap = sock_no_mmap,