Skip to content

route: fixed route_lookup() to be LPM compliant #20

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

Open
y4hu wants to merge 1 commit into
base: master
Choose a base branch
from
Open

route: fixed route_lookup() to be LPM compliant #20

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
26 changes: 24 additions & 2 deletions src/route.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,21 @@ extern struct netdev *loop;
extern char *tapaddr;
extern char *taproute;

static uint8_t route_mask_len(uint32_t mask)
{
uint8_t bits_set = 0;

while (mask) {
if (mask & 1) {
bits_set++;
}

mask >>= 1;
}

return bits_set;
}

static struct rtentry *route_alloc(uint32_t dst, uint32_t gateway, uint32_t netmask,
uint8_t flags, uint32_t metric, struct netdev *dev)
{
Expand Down Expand Up @@ -47,14 +62,21 @@ struct rtentry *route_lookup(uint32_t daddr)
{
struct list_head *item;
struct rtentry *rt = NULL;
struct rtentry *lpm_rt = NULL;
uint8_t longest_match = 0;

list_for_each(item, &routes) {
rt = list_entry(item, struct rtentry, list);
if ((daddr & rt->netmask) == (rt->dst & rt->netmask)) break;
if ((daddr & rt->netmask) == (rt->dst & rt->netmask)) {
if (!lpm_rt || (route_mask_len(rt->netmask) > longest_match)) {
lpm_rt = rt;
longest_match = route_mask_len(rt->netmask);
}
}
// If no matches, we default to to default gw (last item)
}

return rt;
return lpm_rt;
}

void free_routes()
Expand Down