From 24c064ccbf819f85c8709ea60acb3b278377b408 Mon Sep 17 00:00:00 2001
From: Hans Dedecker <dedeckeh@gmail.com>
Date: Wed, 23 Oct 2013 12:04:01 +0000
Subject: [PATCH] odhcp6c: message retransmission count support
The patch implements message retransmission count (MRC) support as
described in RFC3315 paragraphs 5.5 and 14 for DHCPv6 request/release/
decline messages. Patch also disables multicast packets loopback.
Signed-off-by: Hans Dedecker <hans.dedecker@gmail.com>
---
src/dhcpv6.c | 83 ++++++++++++++++++++++++++++-----------------------
src/odhcp6c.h | 4 +--
2 files changed, 48 insertions(+), 39 deletions(-)
diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index f905a78..08e3225 100644
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -58,20 +58,20 @@ static int dhcpv6_commit_advert(void);
// RFC 3315 - 5.5 Timeout and Delay values
static struct dhcpv6_retx dhcpv6_retx[_DHCPV6_MSG_MAX] = {
- [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, "<POLL>",
- dhcpv6_handle_reconfigure, NULL},
- [DHCPV6_MSG_SOLICIT] = {true, 1, 120, "SOLICIT",
- dhcpv6_handle_advert, dhcpv6_commit_advert},
- [DHCPV6_MSG_REQUEST] = {true, 1, 30, "REQUEST",
- dhcpv6_handle_reply, NULL},
- [DHCPV6_MSG_RENEW] = {false, 10, 600, "RENEW",
- dhcpv6_handle_reply, NULL},
- [DHCPV6_MSG_REBIND] = {false, 10, 600, "REBIND",
- dhcpv6_handle_rebind_reply, NULL},
- [DHCPV6_MSG_RELEASE] = {false, 1, 600, "RELEASE", NULL, NULL},
- [DHCPV6_MSG_DECLINE] = {false, 1, 3, "DECLINE", NULL, NULL},
- [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, "INFOREQ",
- dhcpv6_handle_reply, NULL},
+ [DHCPV6_MSG_UNKNOWN] = {false, 1, 120, 0, "<POLL>",
+ dhcpv6_handle_reconfigure, NULL},
+ [DHCPV6_MSG_SOLICIT] = {true, 1, 3600, 0, "SOLICIT",
+ dhcpv6_handle_advert, dhcpv6_commit_advert},
+ [DHCPV6_MSG_REQUEST] = {true, 1, 30, 10, "REQUEST",
+ dhcpv6_handle_reply, NULL},
+ [DHCPV6_MSG_RENEW] = {false, 10, 600, 0, "RENEW",
+ dhcpv6_handle_reply, NULL},
+ [DHCPV6_MSG_REBIND] = {false, 10, 600, 0, "REBIND",
+ dhcpv6_handle_rebind_reply, NULL},
+ [DHCPV6_MSG_RELEASE] = {false, 1, 0, 5, "RELEASE", NULL, NULL},
+ [DHCPV6_MSG_DECLINE] = {false, 1, 0, 5, "DECLINE", NULL, NULL},
+ [DHCPV6_MSG_INFO_REQ] = {true, 1, 120, 0, "INFOREQ",
+ dhcpv6_handle_reply, NULL},
};
@@ -157,6 +157,8 @@ int init_dhcpv6(const char *ifname, int request_pd, int sol_timeout)
int val = 1;
setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &val, sizeof(val));
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
+ val = 0;
+ setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val, sizeof(val));
setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
@@ -360,7 +362,7 @@ static int64_t dhcpv6_rand_delay(int64_t time)
int dhcpv6_request(enum dhcpv6_msg type)
{
- uint8_t buf[1536];
+ uint8_t buf[1536], rc = 0;
uint64_t timeout = UINT32_MAX;
struct dhcpv6_retx *retx = &dhcpv6_retx[type];
@@ -370,11 +372,7 @@ int dhcpv6_request(enum dhcpv6_msg type)
nanosleep(&ts, NULL);
}
- if (type == DHCPV6_MSG_REQUEST)
- timeout = 60;
- else if (type == DHCPV6_MSG_RELEASE || type == DHCPV6_MSG_DECLINE)
- timeout = 3;
- else if (type == DHCPV6_MSG_UNKNOWN)
+ if (type == DHCPV6_MSG_UNKNOWN)
timeout = t1;
else if (type == DHCPV6_MSG_RENEW)
timeout = (t2 > t1) ? t2 - t1 : 0;
@@ -384,7 +382,7 @@ int dhcpv6_request(enum dhcpv6_msg type)
if (timeout == 0)
return -1;
- syslog(LOG_NOTICE, "Sending %s (timeout %us)", retx->name, (unsigned)timeout);
+ syslog(LOG_NOTICE, "Starting %s transaction (timeout %llus, max rc %d)", retx->name, timeout, retx->max_rc);
uint64_t start = odhcp6c_get_milli_time(), round_start = start, elapsed;
@@ -396,11 +394,19 @@ int dhcpv6_request(enum dhcpv6_msg type)
int64_t rto = 0;
do {
- rto = (rto == 0) ? (retx->init_timeo * 1000 +
- dhcpv6_rand_delay(retx->init_timeo * 1000)) :
- (2 * rto + dhcpv6_rand_delay(rto));
+ if (rto == 0) {
+ int64_t delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
- if (rto >= retx->max_timeo * 1000)
+ // First RT MUST be strictly greater than IRT for solicit messages (RFC3313 17.1.2)
+ while (type == DHCPV6_MSG_SOLICIT && delay <= 0)
+ delay = dhcpv6_rand_delay(retx->init_timeo * 1000);
+
+ rto = (retx->init_timeo * 1000 + delay);
+ }
+ else
+ rto = (2 * rto + dhcpv6_rand_delay(rto));
+
+ if (retx->max_timeo && (rto >= retx->max_timeo * 1000))
rto = retx->max_timeo * 1000 +
dhcpv6_rand_delay(retx->max_timeo * 1000);
@@ -413,8 +419,11 @@ int dhcpv6_request(enum dhcpv6_msg type)
round_end = timeout * 1000 + start;
// Built and send package
- if (type != DHCPV6_MSG_UNKNOWN)
+ if (type != DHCPV6_MSG_UNKNOWN) {
+ syslog(LOG_NOTICE, "Send %s message (elapsed %llums, rc %d)", retx->name, elapsed, rc);
dhcpv6_send(type, trid, elapsed / 10);
+ rc++;
+ }
// Receive rounds
for (; len < 0 && round_start < round_end;
@@ -442,11 +451,11 @@ int dhcpv6_request(enum dhcpv6_msg type)
round_start = odhcp6c_get_milli_time();
elapsed = round_start - start;
syslog(LOG_NOTICE, "Got a valid reply after "
- "%ums", (unsigned)elapsed);
+ "%llums", elapsed);
if (retx->handler_reply)
len = retx->handler_reply(
- type, opt, opt_end);
+ type, rc, opt, opt_end);
if (len > 0 && round_end - round_start > 1000)
round_end = 1000 + round_start;
@@ -456,7 +465,7 @@ int dhcpv6_request(enum dhcpv6_msg type)
// Allow
if (retx->handler_finish)
len = retx->handler_finish();
- } while (len < 0 && elapsed / 1000 < timeout);
+ } while (len < 0 && ((elapsed / 1000 < timeout) && (!retx->max_rc || rc < retx->max_rc)));
return len;
}
@@ -547,7 +556,7 @@ int dhcpv6_poll_reconfigure(void)
}
-static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig,
+static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig, const int rc,
const void *opt, const void *end)
{
// TODO: should verify the reconfigure message
@@ -559,13 +568,13 @@ static int dhcpv6_handle_reconfigure(_unused enum dhcpv6_msg orig,
odata[0] == DHCPV6_MSG_INFO_REQ))
msg = odata[0];
- dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL);
+ dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
return msg;
}
// Collect all advertised servers
-static int dhcpv6_handle_advert(enum dhcpv6_msg orig,
+static int dhcpv6_handle_advert(enum dhcpv6_msg orig, _unused const int rc,
const void *opt, const void *end)
{
uint16_t olen, otype;
@@ -689,20 +698,20 @@ static int dhcpv6_commit_advert(void)
}
-static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig,
+static int dhcpv6_handle_rebind_reply(enum dhcpv6_msg orig, const int rc,
const void *opt, const void *end)
{
- dhcpv6_handle_advert(orig, opt, end);
+ dhcpv6_handle_advert(orig, rc, opt, end);
if (dhcpv6_commit_advert() < 0) {
- dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, NULL, NULL);
+ dhcpv6_handle_reply(DHCPV6_MSG_UNKNOWN, rc, NULL, NULL);
return -1;
}
- return dhcpv6_handle_reply(orig, opt, end);
+ return dhcpv6_handle_reply(orig, rc, opt, end);
}
-static int dhcpv6_handle_reply(enum dhcpv6_msg orig,
+static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
const void *opt, const void *end)
{
uint8_t *odata;
diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index 61dee63..5b9b78f 100644
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -85,7 +85,7 @@ enum dhcpv6_status {
DHCPV6_NoPrefixAvail = 6,
};
-typedef int(reply_handler)(enum dhcpv6_msg orig,
+typedef int(reply_handler)(enum dhcpv6_msg orig, const int rc,
const void *opt, const void *end);
// retransmission strategy
@@ -93,12 +93,12 @@ struct dhcpv6_retx {
bool delay;
uint8_t init_timeo;
uint16_t max_timeo;
+ uint8_t max_rc;
char name[8];
reply_handler *handler_reply;
int(*handler_finish)(void);
};
-
// DHCPv6 Protocol Headers
struct dhcpv6_header {
uint8_t msg_type;
--
2.39.5