Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

fix: Fake broadcast address for 127.x.x.x #2760

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

fix: Fake broadcast address for 127.x.x.x #2760

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
29 changes: 25 additions & 4 deletions toxcore/LAN_discovery.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -121,6 +121,9 @@ static Broadcast_Info *fetch_broadcast_info(const Network *ns)

#elif !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && (defined(__linux__) || defined(__FreeBSD__) || defined(__DragonFly__))

non_null()
static bool ip4_is_local(const IP4 *ip4);

non_null()
static Broadcast_Info *fetch_broadcast_info(const Network *ns)
{
Expand Down Expand Up @@ -162,7 +165,8 @@ static Broadcast_Info *fetch_broadcast_info(const Network *ns)
const int n = ifc.ifc_len / sizeof(struct ifreq);

for (int i = 0; i < n; ++i) {
/* there are interfaces with are incapable of broadcast */
/* there are interfaces with are incapable of broadcast
on Linux, `lo` has no broadcast address, but this function returns >=0 */
if (ioctl(net_socket_to_native(sock), SIOCGIFBRDADDR, &i_faces[i]) < 0) {
continue;
}
Expand All @@ -172,18 +176,35 @@ static Broadcast_Info *fetch_broadcast_info(const Network *ns)
continue;
}

const struct sockaddr_in *sock4 = (const struct sockaddr_in *)(void *)&i_faces[i].ifr_broadaddr;
const struct sockaddr_in *broadaddr4 = (const struct sockaddr_in *)(void *)&i_faces[i].ifr_broadaddr;

if (broadcast->count >= MAX_INTERFACES) {
break;
}

IP *ip = &broadcast->ips[broadcast->count];
ip->family = net_family_ipv4();
ip->ip.v4.uint32 = sock4->sin_addr.s_addr;
ip->ip.v4.uint32 = broadaddr4->sin_addr.s_addr;

// if no broadcast address
if (ip->ip.v4.uint32 == 0) {
continue;
if (ioctl(net_socket_to_native(sock), SIOCGIFADDR, &i_faces[i]) < 0) {
continue;
}

const struct sockaddr_in *addr4 = (const struct sockaddr_in *)(void *)&i_faces[i].ifr_addr;


IP4 ip4_staging;
ip4_staging.uint32 = addr4->sin_addr.s_addr;

if (ip4_is_local(&ip4_staging)) {
// this is 127.x.x.x
ip->ip.v4.uint32 = ip4_staging.uint32;
} else {
// give up.
continue;
}
}

++broadcast->count;
Expand Down
Loading