Ignore unexpected DHCP messages - sdhcp - simple dhcp client
(HTM) git clone git://git.codemadness.org/sdhcp
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---
(DIR) commit f397bb3ea1de20c1cac1baf2e091f2ec8c79ec82
(DIR) parent 219b8fe1c38097c37de89b0c8c2aa771ebe1daff
(HTM) Author: Michael Forney <mforney@mforney.org>
Date: Wed, 14 Nov 2018 18:40:35 -0800
Ignore unexpected DHCP messages
Diffstat:
M sdhcp.c | 92 ++++++++++++++++---------------
1 file changed, 47 insertions(+), 45 deletions(-)
---
(DIR) diff --git a/sdhcp.c b/sdhcp.c
@@ -356,30 +356,30 @@ Init:
alarm(1);
goto Selecting;
Selecting:
- switch (dhcprecv()) {
- case DHCPoffer:
- alarm(0);
- memcpy(client, bp.yiaddr, sizeof(client));
- optget(&bp, server, ODserverid, sizeof(server));
- optget(&bp, mask, OBmask, sizeof(mask));
- optget(&bp, router, OBrouter, sizeof(router));
- optget(&bp, dns, OBdnsserver, sizeof(dns));
- optget(&bp, &t1, ODlease, sizeof(t1));
- t1 = ntohl(t1);
- dhcpsend(DHCPrequest, Broadcast);
- goto Requesting;
- case Timeout:
- goto Init;
- default:
- goto Selecting;
+ for (;;) {
+ switch (dhcprecv()) {
+ case DHCPoffer:
+ alarm(0);
+ memcpy(client, bp.yiaddr, sizeof(client));
+ optget(&bp, server, ODserverid, sizeof(server));
+ optget(&bp, mask, OBmask, sizeof(mask));
+ optget(&bp, router, OBrouter, sizeof(router));
+ optget(&bp, dns, OBdnsserver, sizeof(dns));
+ optget(&bp, &t1, ODlease, sizeof(t1));
+ t1 = ntohl(t1);
+ dhcpsend(DHCPrequest, Broadcast);
+ goto Requesting;
+ case Timeout:
+ goto Init;
+ }
}
Requesting:
- switch (dhcprecv()) {
- case DHCPoffer:
- goto Requesting; /* ignore other offers. */
- case DHCPack:
- acceptlease();
- goto Bound;
+ for (;;) {
+ switch (dhcprecv()) {
+ case DHCPack:
+ acceptlease();
+ goto Bound;
+ }
}
Bound:
fputs("Congrats! You should be on the 'net.\n", stdout);
@@ -388,33 +388,35 @@ Bound:
exit(0);
forked = 1;
}
- switch (dhcprecv()) {
- case DHCPoffer:
- case DHCPack:
- case DHCPnak:
- goto Bound; /* discard offer, ACK or NAK */
- case Timeout:
- dhcpsend(DHCPrequest, Unicast);
- goto Renewing;
+ for (;;) {
+ switch (dhcprecv()) {
+ case Timeout:
+ dhcpsend(DHCPrequest, Unicast);
+ goto Renewing;
+ }
}
Renewing:
- switch (dhcprecv()) {
- case DHCPack:
- acceptlease();
- goto Bound;
- case DHCPnak:
- goto Init;
- case Timeout:
- dhcpsend(DHCPrequest, Broadcast);
- goto Rebinding;
+ for (;;) {
+ switch (dhcprecv()) {
+ case DHCPack:
+ acceptlease();
+ goto Bound;
+ case DHCPnak:
+ goto Init;
+ case Timeout:
+ dhcpsend(DHCPrequest, Broadcast);
+ goto Rebinding;
+ }
}
Rebinding:
- switch (dhcprecv()) {
- case DHCPnak: /* lease expired */
- goto Init;
- case DHCPack:
- acceptlease();
- goto Bound;
+ for (;;) {
+ switch (dhcprecv()) {
+ case DHCPnak: /* lease expired */
+ goto Init;
+ case DHCPack:
+ acceptlease();
+ goto Bound;
+ }
}
}