1
0
Fork 0
mirror of https://passt.top/passt synced 2025-07-30 12:58:00 +02:00

conf: Use 0 instead of -1 as "unassigned" mtu value

On the command line -m 0 means "don't assign an MTU" (letting the guest use
its default.  However, internally we use (c->mtu == -1) to represent that
state.  We use (c->mtu == 0) to represent "the user didn't specify on the
command line, so use the default" - but this is only used during conf(),
never afterwards.

This is unnecessarily confusing.  We can instead just initialise c->mtu to
its default (65520) before parsing options and use 0 on both the command
line and internally to represent the "don't assign" special case.  This
ensures that c->mtu is always 0..65535, so we can store it in a uint16_t
which is more natural.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
David Gibson 2025-02-19 14:14:28 +11:00 committed by Stefano Brivio
commit 1cc5d4c9fe
6 changed files with 8 additions and 14 deletions

View file

@ -274,6 +274,8 @@ struct ctx {
int fd_repair;
unsigned char our_tap_mac[ETH_ALEN];
unsigned char guest_mac[ETH_ALEN];
uint16_t mtu;
uint64_t hash_secret[2];
int ifi4;
@ -298,7 +300,6 @@ struct ctx {
int no_icmp;
struct icmp_ctx icmp;
int mtu;
int no_dns;
int no_dns_search;
int no_dhcp_dns;