diff options
| author | Al Viro | 2017-06-26 13:19:16 -0400 |
|---|---|---|
| committer | Al Viro | 2018-01-24 19:13:45 -0500 |
| commit | 36fd633ec98acd2028585c22128fcaa3da6d5770 (patch) | |
| tree | 1fa77e8bf1662dea936b52107a0d39485110edb1 /net/ipv4 | |
| parent | be1b6e8b5470e8311bfa1a3dfd7bd59e85a99759 (diff) | |
net: separate SIOCGIFCONF handling from dev_ioctl()
Only two of dev_ioctl() callers may pass SIOCGIFCONF to it.
Separating that codepath from the rest of dev_ioctl() allows both
to simplify dev_ioctl() itself (all other cases work with struct ifreq *)
*and* seriously simplify the compat side of that beast: all it takes
is passing to inet_gifconf() an extra argument - the size of individual
records (sizeof(struct ifreq) or sizeof(struct compat_ifreq)). With
dev_ifconf() called directly from sock_do_ioctl()/compat_dev_ifconf()
that's easy to arrange.
As the result, compat side of SIOCGIFCONF doesn't need any
allocations, copy_in_user() back and forth, etc.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/devinet.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 7a93359fbc72..1771549d2438 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1188,22 +1188,25 @@ rarok: goto out; } -static int inet_gifconf(struct net_device *dev, char __user *buf, int len) +static int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size) { struct in_device *in_dev = __in_dev_get_rtnl(dev); struct in_ifaddr *ifa; struct ifreq ifr; int done = 0; + if (WARN_ON(size > sizeof(struct ifreq))) + goto out; + if (!in_dev) goto out; for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) { if (!buf) { - done += sizeof(ifr); + done += size; continue; } - if (len < (int) sizeof(ifr)) + if (len < size) break; memset(&ifr, 0, sizeof(struct ifreq)); strcpy(ifr.ifr_name, ifa->ifa_label); @@ -1212,13 +1215,12 @@ static int inet_gifconf(struct net_device *dev, char __user *buf, int len) (*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr = ifa->ifa_local; - if (copy_to_user(buf, &ifr, sizeof(struct ifreq))) { + if (copy_to_user(buf + done, &ifr, size)) { done = -EFAULT; break; } - buf += sizeof(struct ifreq); - len -= sizeof(struct ifreq); - done += sizeof(struct ifreq); + len -= size; + done += size; } out: return done; |