[PATCH v2 2/3] dhcp: Introduce support for Rapid Commit (option 80, RFC 4039)

[Stefano Brivio <sbrivio@redhat.com>]

I'm trying to speed up and simplify IP address acquisition in muvm.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 dhcp.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/dhcp.c b/dhcp.c
index 2fe4a4d..aa0ad96 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -342,8 +342,14 @@ int dhcp(const struct ctx *c, const struct pool *p)
 	}
 
 	if (opts[53].c[0] == DHCPDISCOVER) {
-		info("DHCP: offer to discover");
-		opts[53].s[0] = DHCPOFFER;
+		if (opts[80].clen == -1) {
+			info("DHCP: offer to discover");
+			opts[53].s[0] = DHCPOFFER;
+		} else {
+			info("DHCP: ack to discover (Rapid Commit)");
+			opts[53].s[0] = DHCPACK;
+			opts[80].slen = 0;
+		}
 	} else if (opts[53].c[0] == DHCPREQUEST || opts[53].clen <= 0) {
 		info("%s: ack to request",
 		     (opts[53].clen <= 0) ? "DHCP" : "BOOTP");
-- 
@@ -342,8 +342,14 @@ int dhcp(const struct ctx *c, const struct pool *p)
 	}
 
 	if (opts[53].c[0] == DHCPDISCOVER) {
-		info("DHCP: offer to discover");
-		opts[53].s[0] = DHCPOFFER;
+		if (opts[80].clen == -1) {
+			info("DHCP: offer to discover");
+			opts[53].s[0] = DHCPOFFER;
+		} else {
+			info("DHCP: ack to discover (Rapid Commit)");
+			opts[53].s[0] = DHCPACK;
+			opts[80].slen = 0;
+		}
 	} else if (opts[53].c[0] == DHCPREQUEST || opts[53].clen <= 0) {
 		info("%s: ack to request",
 		     (opts[53].clen <= 0) ? "DHCP" : "BOOTP");
-- 
2.43.0