From ec2b58ea4dc45079470efedaa632da25031d5adc Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Tue, 7 Sep 2021 11:19:57 +0200 Subject: conf, dhcp, ndp: Fix message about default MTU, make NDP consistent Signed-off-by: Stefano Brivio --- conf.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'conf.c') diff --git a/conf.c b/conf.c index fd8f3cf..2622a38 100644 --- a/conf.c +++ b/conf.c @@ -617,7 +617,9 @@ static void usage(const char *name) info(" /tmp/passt_ISO8601-TIMESTAMP_INSTANCE-NUMBER.pcap"); info( " -m, --mtu MTU Assign MTU via DHCP/NDP"); - info( " default: no MTU assigned via DHCP/NDP options"); + info( " a zero value disables assignment"); + info( " default: 65520: maximum 802.3 MTU minus 802.3 header"); + info( " length, rounded to 32 bits (IPv4 words)"); info( " -a, --address ADDR Assign IPv4 or IPv6 address ADDR"); info( " can be specified zero to two times (for IPv4 and IPv6)"); info( " default: use addresses from interface with default route"); @@ -954,6 +956,12 @@ void conf(struct ctx *c, int argc, char **argv) errno = 0; c->mtu = strtol(optarg, NULL, 0); + + if (!c->mtu) { + c->mtu = -1; + break; + } + if (c->mtu < ETH_MIN_MTU || c->mtu > (int)ETH_MAX_MTU || errno) { err("Invalid MTU: %s", optarg); @@ -1132,6 +1140,11 @@ void conf(struct ctx *c, int argc, char **argv) } } + if (!c->mtu) { + c->mtu = (ETH_MAX_MTU - ETH_HLEN) / + sizeof(uint32_t) * sizeof(uint32_t); + } + get_routes(c); get_addrs(c); -- cgit v1.2.3