From 961c082f70fa51c2110b176d821bf92d198c01d0 Mon Sep 17 00:00:00 2001
From: Peter Qiu <zqiu@chromium.org>
Date: Fri, 29 May 2015 09:44:36 -0700
Subject: [PATCH] ChromiumOS DHCPv6 support

Add support to emit DHCPv6 configuration/status updates through
DBus, and prevent the daemon from updating IPv6 system configurations.

Add command line option "-a" to enable ia options for shill usage,
since ia options can only be specified through the config file by
default.  When "-a" option is enabled, the daemon will request ia_na
(Non-temporary Address) and ia_pd (Prefix Delegation) options from
the DHCPv6 server.

BUG=chromium:496751
TEST=Verify using upcoming client test network_Dhcpv6*
Manual Test:
1. Create a virtual ethernet pair and setup a DHCPv6 server on the
   master interface (veth_master) using dhcpd:
   "dhcpd -6 -d -cf /tmp/dhcp6.conf veth_master"
   with following config:
       default-lease-time 600;
       max-lease-time 7200;
       subnet6 2001:db8:0:1::/64 {
           # Range for clients
           range6 2001:db8:0:1::129 2001:db8:0:1::254;
           # Additional options
           option dhcp6.name-servers fec0:0:0:1::1;
           option dhcp6.domain-search "domain.example";
           # Prefix range for delegation to sub-routers
           prefix6 2001:db8:0:100:: 2001:db8:0:f00:: /56;
       }
2. Start DBus monitor using "dbus-monitor --system"
3. Start a DHCPv6 client on the slave interface using dhcpcd:
   "dhcpcd -6 -B -a veth_slave"
4. Verify DHCPv6 configurations through DBus messages.
---
 dbus/rpc-dbus.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 dhcp-common.c   |   2 +-
 dhcp6.c         |  12 +++++++
 dhcpcd.conf     |   3 ++
 if-options.c    |  39 ++++++++++++++++++++
 if-options.h    |   2 +-
 ipv6.c          |   6 ++++
 rpc-interface.h |   2 ++
 rpc-stub.c      |   2 ++
 9 files changed, 174 insertions(+), 3 deletions(-)

diff --git a/dbus/rpc-dbus.c b/dbus/rpc-dbus.c
index cc88356..ea380c4 100644
--- a/dbus/rpc-dbus.c
+++ b/dbus/rpc-dbus.c
@@ -39,6 +39,9 @@
 #include "../config.h"
 #include "../eloop.h"
 #include "../dhcp.h"
+#ifdef INET6
+#include "../dhcp6.h"
+#endif
 #include "../rpc-interface.h"
 #include "dbus-dict.h"
 
@@ -217,6 +220,23 @@ static const struct o_dbus dhos[] = {
 	{ "domain_search=", DBUS_TYPE_ARRAY, DBUS_TYPE_STRING,
 	  "DomainSearch" },
 	{ "wpad_url=", DBUS_TYPE_STRING, 0, "WebProxyAutoDiscoveryUrl" },
+#ifdef INET6
+	{ "dhcp6_server_id=", DBUS_TYPE_STRING, 0,
+	  "DHCPv6ServerIdentifier" },
+	{ "dhcp6_ia_na1_ia_addr1=", DBUS_TYPE_STRING, 0, "DHCPv6Address" },
+	{ "dhcp6_ia_na1_ia_addr1_vltime=", DBUS_TYPE_UINT32, 0,
+	  "DHCPv6AddressLeaseTime" },
+	{ "dhcp6_name_servers=", DBUS_TYPE_ARRAY, DBUS_TYPE_STRING,
+	  "DHCPv6NameServers" },
+	{ "dhcp6_domain_search=", DBUS_TYPE_ARRAY, DBUS_TYPE_STRING,
+	  "DHCPv6DomainSearch" },
+	{ "dhcp6_ia_pd1_prefix1=", DBUS_TYPE_STRING, 0,
+	  "DHCPv6DelegatedPrefix" },
+	{ "dhcp6_ia_pd1_prefix1_length=", DBUS_TYPE_UINT32, 0,
+	  "DHCPv6DelegatedPrefixLength" },
+	{ "dhcp6_ia_pd1_prefix1_vltime=", DBUS_TYPE_UINT32, 0,
+	  "DHCPv6DelegatedPrefixLeaseTime" },
+#endif
 	{ NULL, 0, 0, NULL }
 };
 
@@ -346,6 +366,83 @@ dbus_send_message(const struct interface *ifp, const char *reason,
 	return success;
 }
 
+#ifdef INET6
+static dbus_bool_t
+dbus_send_dhcpv6_message(const struct interface *ifp, const char *reason,
+    const char *prefix, struct dhcp6_message *message, size_t length)
+{
+	const struct if_options *ifo = ifp->options;
+	DBusMessage* msg;
+	DBusMessageIter args, dict;
+	int pid = getpid();
+	char **env = NULL;
+	ssize_t e, elen;
+	int retval;
+	int success = FALSE;
+
+	syslog(LOG_INFO, "event %s on interface %s", reason, ifp->name);
+
+	msg = dbus_message_new_signal(SERVICE_PATH, SERVICE_NAME, "Event");
+	if (msg == NULL) {
+		syslog(LOG_ERR, "failed to make a configure message");
+		return FALSE;
+	}
+	dbus_message_iter_init_append(msg, &args);
+	dbus_message_iter_append_basic(&args, DBUS_TYPE_UINT32, &pid);
+	dbus_message_iter_append_basic(&args, DBUS_TYPE_STRING, &reason);
+	dbus_message_iter_open_container(&args, DBUS_TYPE_ARRAY,
+	    DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING
+	    DBUS_TYPE_STRING_AS_STRING
+	    DBUS_TYPE_VARIANT_AS_STRING
+	    DBUS_DICT_ENTRY_END_CHAR_AS_STRING,
+	    &dict);
+	if (prefix == NULL || message == NULL)
+		retval = 0;
+	else {
+		e = dhcp6_env(NULL, NULL, ifp, message, length);
+		if (e > 0) {
+			char *config_prefix = strdup(prefix);
+			if (config_prefix == NULL) {
+				logger(dhcpcd_ctx, LOG_ERR,
+				       "Memory exhausted (strdup)");
+				eloop_exit(dhcpcd_ctx->eloop, EXIT_FAILURE);
+			}
+			char *p = config_prefix + strlen(config_prefix) - 1;
+			if (p >= config_prefix && *p == '_')
+				*p = '\0';
+			env = calloc(e + 1, sizeof(char *));
+			if (env == NULL) {
+				logger(dhcpcd_ctx, LOG_ERR,
+				       "Memory exhausted (calloc)");
+				eloop_exit(dhcpcd_ctx->eloop, EXIT_FAILURE);
+			}
+			elen = dhcp6_env(env, "new", ifp, message, length);
+			free(config_prefix);
+		}
+		retval = append_config(&dict, prefix, env, elen);
+	}
+
+	/* Release memory allocated for env. */
+	if (env) {
+		char **current = env;
+		while (*current)
+			free(*current++);
+		free(env);
+	}
+
+	dbus_message_iter_close_container(&args, &dict);
+	if (retval == 0) {
+		success = dbus_connection_send(connection, msg, NULL);
+		if (!success)
+			syslog(LOG_ERR, "failed to send dhcpv6 to dbus");
+	} else
+		syslog(LOG_ERR, "failed to construct dbus message");
+	dbus_message_unref(msg);
+
+	return success;
+}
+#endif
+
 static DBusHandlerResult
 introspect(DBusConnection *con, DBusMessage *msg)
 {
@@ -640,12 +737,22 @@ rpc_update_ipv4(struct interface *ifp)
 	return 0;
 }
 
+#ifdef INET6
 int
 rpc_update_ipv6(struct interface *ifp)
 {
-	/* Currently not supported. */
+	struct dhcp6_state *state = D6_STATE(ifp);
+	if (state->new != NULL) {
+		/* push state over d-bus */
+		dbus_send_dhcpv6_message(ifp, state->reason, "new_",
+					 state->new, state->new_len);
+		rpc_signal_status("Bound6");
+	} else {
+		rpc_signal_status("Release6");
+	}
 	return 0;
 }
+#endif
 
 int
 rpc_notify_unicast_arp(struct interface *ifp) {
diff --git a/dhcp-common.c b/dhcp-common.c
index 70e76ce..b0a2012 100644
--- a/dhcp-common.c
+++ b/dhcp-common.c
@@ -753,7 +753,7 @@ dhcp_set_leasefile(char *leasefile, size_t len, int family,
 				ifp->lease_identifier, "", "");
 	}
 	return snprintf(leasefile, len,
-			family == AF_INET ? LEASEFILE : LEASEFILE,
+			family == AF_INET ? LEASEFILE : LEASEFILE6,
 			ifp->name, "", "");
 }
 
diff --git a/dhcp6.c b/dhcp6.c
index 9b00b40..79b7cf1 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -50,6 +50,7 @@
 #include "if.h"
 #include "if-options.h"
 #include "ipv6nd.h"
+#include "rpc-interface.h"
 #include "script.h"
 
 #ifndef __UNCONST
@@ -1373,6 +1374,7 @@ dhcp6_startdiscover(void *arg)
 	struct interface *ifp;
 	struct dhcp6_state *state;
 
+	rpc_signal_status("Discover6");
 	ifp = arg;
 	dhcp6_delete_delegates(ifp);
 	logger(ifp->ctx, LOG_INFO, "%s: soliciting a DHCPv6 lease", ifp->name);
@@ -1474,6 +1476,7 @@ dhcp6_startrebind(void *arg)
 	struct dhcp6_state *state;
 	int pd;
 
+	rpc_signal_status("Rebind6");
 	ifp = arg;
 	eloop_timeout_delete(ifp->ctx->eloop, dhcp6_sendrenew, ifp);
 	state = D6_STATE(ifp);
@@ -1516,6 +1519,7 @@ dhcp6_startrequest(struct interface *ifp)
 {
 	struct dhcp6_state *state;
 
+	rpc_signal_status("Request6");
 	eloop_timeout_delete(ifp->ctx->eloop, dhcp6_senddiscover, ifp);
 	state = D6_STATE(ifp);
 	state->state = DH6S_REQUEST;
@@ -1539,6 +1543,7 @@ dhcp6_startconfirm(struct interface *ifp)
 {
 	struct dhcp6_state *state;
 
+	rpc_signal_status("Confirm6");
 	state = D6_STATE(ifp);
 	state->state = DH6S_CONFIRM;
 	state->start_uptime = uptime();
@@ -1566,6 +1571,7 @@ dhcp6_startinform(void *arg)
 	struct interface *ifp;
 	struct dhcp6_state *state;
 
+	rpc_signal_status("Inform6");
 	ifp = arg;
 	state = D6_STATE(ifp);
 	if (state->new == NULL || ifp->options->options & DHCPCD_DEBUG)
@@ -1591,6 +1597,7 @@ dhcp6_startexpire(void *arg)
 {
 	struct interface *ifp;
 
+	rpc_signal_status("Expire6");
 	ifp = arg;
 	eloop_timeout_delete(ifp->ctx->eloop, dhcp6_sendrebind, ifp);
 
@@ -1614,6 +1621,7 @@ dhcp6_startrelease(struct interface *ifp)
 	if (state->state != DH6S_BOUND)
 		return;
 
+	rpc_signal_status("Release6");
 	state->state = DH6S_RELEASE;
 	state->start_uptime = uptime();
 	state->RTC = 0;
@@ -3039,9 +3047,13 @@ recv:
 			eloop_timeout_add_sec(ifp->ctx->eloop,
 			    (time_t)state->expire, dhcp6_startexpire, ifp);
 
+#ifndef PASSIVE_MODE
 		ipv6nd_runignoredra(ifp);
 		ipv6_addaddrs(&state->addrs);
 		dhcp6_delegate_prefix(ifp);
+#else
+		rpc_update_ipv6(ifp);
+#endif  /* PASSIVE_MODE */
 
 		if (state->state == DH6S_INFORMED)
 			logger(ifp->ctx, has_new ? LOG_INFO : LOG_DEBUG,
diff --git a/dhcpcd.conf b/dhcpcd.conf
index 3837feb..833c5b6 100644
--- a/dhcpcd.conf
+++ b/dhcpcd.conf
@@ -47,3 +47,6 @@ require dhcp_server_identifier
 # A hook script is provided to lookup the hostname if not set by the DHCP
 # server, but it should not be run by default.
 #nohook lookup-hostname
+
+# Disable IPv6 router solicitation
+noipv6rs
diff --git a/if-options.c b/if-options.c
index 8680b5b..5d32811 100644
--- a/if-options.c
+++ b/if-options.c
@@ -102,6 +102,7 @@
 #define O_BOOTP			O_BASE + 42
 
 const struct option cf_options[] = {
+	{"shill-ipv6",      no_argument,       NULL, 'a'},
 	{"background",      no_argument,       NULL, 'b'},
 	{"script",          required_argument, NULL, 'c'},
 	{"debug",           no_argument,       NULL, 'd'},
@@ -671,6 +672,44 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 	case 'U': /* FALLTHROUGH */
 	case 'V': /* We need to handle non interface options */
 		break;
+#ifdef INET6
+	case 'a':
+		/* Chromeos hack: configure DHCPv6 option for shill. */
+
+		/* Reallocate ia to add both ia_na and ia_pd. */
+		ia = realloc(ifo->ia, sizeof(*ifo->ia) * (ifo->ia_len + 2));
+		if (ia == NULL) {
+			logger(ctx, LOG_ERR, "%s: %m", __func__);
+			return -1;
+		}
+		ifo->ia = ia;
+
+		/* Setup ia_na option with iaid of 0. */
+		ia = &ifo->ia[ifo->ia_len++];
+		ia->ia_type = D6_OPTION_IA_NA;
+		parse_iaid(ia->iaid, "0", sizeof(ia->iaid));
+		ia->iaid_set = 1;
+		memset(&ia->addr, 0, sizeof(ia->addr));
+		ia->prefix_len = 0;
+		ia->sla_max = 0;
+		ia->sla_len = 0;
+		ia->sla = NULL;
+
+		/* Setup ia_pd option with iaid of 1. */
+		ia = &ifo->ia[ifo->ia_len++];
+		ia->ia_type = D6_OPTION_IA_PD;
+		parse_iaid(ia->iaid, "1", sizeof(ia->iaid));
+		ia->iaid_set = 1;
+		memset(&ia->addr, 0, sizeof(ia->addr));
+		ia->prefix_len = 0;
+		ia->sla_max = 0;
+		ia->sla_len = 0;
+		ia->sla = NULL;
+
+		/* Enable ia option. */
+		ifo->options |= DHCPCD_IA_FORCED;
+		break;
+#endif
 	case 'b':
 		ifo->options |= DHCPCD_BACKGROUND;
 		break;
diff --git a/if-options.h b/if-options.h
index f1c45b8..78c4358 100644
--- a/if-options.h
+++ b/if-options.h
@@ -41,7 +41,7 @@
 
 /* Don't set any optional arguments here so we retain POSIX
  * compatibility with getopt */
-#define IF_OPTS "46bc:de:f:gh:i:j:kl:m:no:pqr:s:t:u:v:wxy:z:" \
+#define IF_OPTS "46abc:de:f:gh:i:j:kl:m:no:pqr:s:t:u:v:wxy:z:" \
 		"ABC:DEF:GHI:JKLMO:PQ:RS:TUVW:X:Z:"
 
 #define DEFAULT_TIMEOUT		30
diff --git a/ipv6.c b/ipv6.c
index 66c2fca..7fe3c32 100644
--- a/ipv6.c
+++ b/ipv6.c
@@ -609,6 +609,7 @@ ipv6_checkaddrflags(void *arg)
 static void
 ipv6_deleteaddr(struct ipv6_addr *ia)
 {
+#ifndef PASSIVE_MODE
 	struct ipv6_state *state;
 	struct ipv6_addr *ap;
 
@@ -626,11 +627,13 @@ ipv6_deleteaddr(struct ipv6_addr *ia)
 			break;
 		}
 	}
+#endif
 }
 
 int
 ipv6_addaddr(struct ipv6_addr *ap, const struct timespec *now)
 {
+#ifndef PASSIVE_MODE
 	struct interface *ifp;
 	struct ipv6_state *state;
 	struct ipv6_addr *nap;
@@ -741,6 +744,7 @@ ipv6_addaddr(struct ipv6_addr *ap, const struct timespec *now)
 		    &tv, ipv6_checkaddrflags, ap);
 	}
 #endif
+#endif
 
 	return 0;
 }
@@ -2016,6 +2020,7 @@ ipv6_build_dhcp_routes(struct dhcpcd_ctx *ctx,
 void
 ipv6_buildroutes(struct dhcpcd_ctx *ctx)
 {
+#ifndef PASSIVE_MODE
 	struct rt6_head dnr, *nrs;
 	struct rt6 *rt, *rtn, *or;
 	uint8_t have_default;
@@ -2119,4 +2124,5 @@ ipv6_buildroutes(struct dhcpcd_ctx *ctx)
 
 	free(ctx->ipv6->routes);
 	ctx->ipv6->routes = nrs;
+#endif
 }
diff --git a/rpc-interface.h b/rpc-interface.h
index 6e1e7e0..cf4da46 100644
--- a/rpc-interface.h
+++ b/rpc-interface.h
@@ -42,8 +42,10 @@ void rpc_signal_status(const char *);
 /* Update IPv4 configuration. Return 0 on success. */
 int rpc_update_ipv4(struct interface *ifp);
 
+#ifdef INET6
 /* Update IPv6 configuration. Return 0 on success. */
 int rpc_update_ipv6(struct interface *ifp);
+#endif
 
 /* Emit notification for successful unicast ARP. Return 0 on success. */
 int rpc_notify_unicast_arp(struct interface *ifp);
diff --git a/rpc-stub.c b/rpc-stub.c
index aa65097..e2b4ed9 100644
--- a/rpc-stub.c
+++ b/rpc-stub.c
@@ -53,12 +53,14 @@ rpc_update_ipv4(struct interface *ifp)
 	return 0;
 }
 
+#ifdef INET6
 int
 rpc_update_ipv6(struct interface *ifp)
 {
 	/* Stub implementation. */
 	return 0;
 }
+#endif
 
 int
 rpc_notify_unicast_arp(struct interface *ifp)
-- 
2.2.0.rc0.207.ga3a616c