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Merged
guto86 merged 2 commits into from
Oct 15, 2026
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SHARMAN-4397 : Implement IPv6 DAD recovery mechanism and enhance addr… #233

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7a44742
SHARMAN-4397 : Implement IPv6 DAD recovery mechanism and enhance addr…
S-Parthiban-Selvaraj Oct 13, 2026
e3ffed0
Rename DAD recovery function for clarity and update its usage in addr…
S-Parthiban-Selvaraj Oct 15, 2026
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1 change: 1 addition & 0 deletions source/TR-181/include/wanmgr_dml.h
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Original file line number Diff line number Diff line change
Expand Up @@ -437,6 +437,7 @@ typedef struct _DML_WANIFACE_IP
BOOL Ipv6Changed;
BOOL Ipv4Renewed;
BOOL Ipv6Renewed;
BOOL Ipv6DadRecoveryAttempted; /**< TRUE once the WAN IPv6 address has been deleted/re-added during the current DAD failure cycle */
WANMGR_IPV4_DATA Ipv4Data;
WANMGR_IPV6_DATA Ipv6Data;
WANMGR_IPV6_RA_DATA Ipv6RA;
Expand Down
1 change: 1 addition & 0 deletions source/WanManager/wanmgr_dhcp_event_handler.c
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Expand Up @@ -248,6 +248,7 @@ void WanMgr_ProcessDhcpClientEvent(DhcpEventThreadArgs *eventData)
DHCP_MGR_IPV6_MSG* leaseInfo = &(eventData->lease.v6);
copyDhcpv6Data(&(pVirtIf->IP.Ipv6Data), leaseInfo);
pVirtIf->IP.Ipv6Changed = TRUE;
pVirtIf->IP.Ipv6DadRecoveryAttempted = FALSE; // new lease/address, allow a fresh DAD recovery cycle
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CcspTraceInfo(("%s %d - IPv6 - RestartConnectivityCheck triggered. \n", __FUNCTION__, __LINE__));
pVirtIf->IP.RestartConnectivityCheck = TRUE;
//TODO : WAN ip creation from IA_PD if required. address assignment on LAN bridge.
Expand Down
83 changes: 71 additions & 12 deletions source/WanManager/wanmgr_interface_sm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -211,7 +211,7 @@ static ANSC_STATUS WanManager_ClearDHCPData(DML_VIRTUAL_IFACE * pVirtIf);
* lan ipv6 address ready to use.
* @return RETURN_OK on success else RETURN_ERR
*************************************************************************************/
static int checkIpv6AddressIsReadyToUse(DML_VIRTUAL_IFACE* p_VirtIf);
static int checkIpv6AddressIsReadyToUse(DML_VIRTUAL_IFACE* p_VirtIf, IFACE_TYPE IfaceType);

#ifdef FEATURE_DSLITE_V2
/*************************************************************************************
Expand Down Expand Up @@ -1111,20 +1111,48 @@ static int WanMgr_IsIpv6DADComplete(const char *ifName)
return addressFound && !dadIncomplete;
}

/*
* Force the kernel to restart Duplicate Address Detection (DAD) for the WAN IPv6
* address by removing it and adding it back on the same interface.
*/
static void WanMgr_Ipv6DadRecovery_ReConfigureAddress(DML_VIRTUAL_IFACE* p_VirtIf)
{
char cmdLine[BUFLEN_256] = {0};

if (p_VirtIf->IP.Ipv6Data.address[0] == '\0')
{
return;
}

snprintf(cmdLine, sizeof(cmdLine), "ip -6 addr del %s/128 dev %s", p_VirtIf->IP.Ipv6Data.address, p_VirtIf->Name);
WanManager_DoSystemActionWithStatus("checkIpv6AddressIsReadyToUse: DAD recovery - delete address", cmdLine);

snprintf(cmdLine, sizeof(cmdLine), "ip -6 addr add %s/128 dev %s", p_VirtIf->IP.Ipv6Data.address, p_VirtIf->Name);
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if (WanManager_DoSystemActionWithStatus("checkIpv6AddressIsReadyToUse: DAD recovery - re-add address", cmdLine) != 0)
{
CcspTraceError(("%s %d - Failed to re-add IPv6 address %s on '%s' during DAD recovery\n",
__FUNCTION__, __LINE__, p_VirtIf->IP.Ipv6Data.address, p_VirtIf->Name));
}
}

/**
* @brief Checks if the IPv6 address is ready to use.
*
* This function checks the tentative address, detects Duplicate Address Detection (DAD)
* failure, and verifies that a default route is present.
* If the default route is missing, it triggers a Router Solicitation.
*
* If DAD does not complete within 15 seconds, the address is deleted and re-added to force
* a fresh DAD cycle. If DAD still hasn't completed 15 seconds after that, the DHCPv6 client
* is restarted on the interface to recover.
*
* @param p_VirtIf Pointer to the virtual interface structure.
* @param IfaceType Type of the base WAN interface, needed to restart the DHCPv6 client.
* @return int 0 on success, negative value on failure.
*/
static int checkIpv6AddressIsReadyToUse(DML_VIRTUAL_IFACE* p_VirtIf)
static int checkIpv6AddressIsReadyToUse(DML_VIRTUAL_IFACE* p_VirtIf, IFACE_TYPE IfaceType)
{
char buffer[BUFLEN_256] = {0};
FILE *fp_dad = NULL;
FILE *fp_route = NULL;
int dad_flag = 0;
int route_flag = 0;
Expand All @@ -1147,6 +1175,38 @@ static int checkIpv6AddressIsReadyToUse(DML_VIRTUAL_IFACE* p_VirtIf)
sleep(1);
}

if (dad_flag == 0 && p_VirtIf->IP.Ipv6DadRecoveryAttempted == FALSE)
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{
CcspTraceError(("%s %d - DAD check failed for %s on '%s' after 15 sec, deleting and re-adding the address to recover\n",
__FUNCTION__, __LINE__, p_VirtIf->IP.Ipv6Data.address, p_VirtIf->Name));

WanMgr_Ipv6DadRecovery_ReConfigureAddress(p_VirtIf);
p_VirtIf->IP.Ipv6DadRecoveryAttempted = TRUE;

for(int i=0; i<15; i++)
{
if (WanMgr_IsIpv6DADComplete(p_VirtIf->Name))
{
dad_flag = 1;
break;
}

sleep(1);
}

if (dad_flag == 0)
{
CcspTraceError(("%s %d - DAD still failing for %s on '%s' after address recovery, restarting DHCPv6 client with release\n",
__FUNCTION__, __LINE__, p_VirtIf->IP.Ipv6Data.address, p_VirtIf->Name));
WanManager_RestartDhcpv6Client(p_VirtIf, IfaceType);
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}
}

if (dad_flag == 1)
{
p_VirtIf->IP.Ipv6DadRecoveryAttempted = FALSE;
}

buffer[0] = '\0';
char cmd[128];
snprintf(cmd, sizeof(cmd), "ip -6 ro show default dev %s", p_VirtIf->Name);
Expand All @@ -1160,7 +1220,6 @@ static int checkIpv6AddressIsReadyToUse(DML_VIRTUAL_IFACE* p_VirtIf)
}
}

//if DAD failed on WAN interface, log an ERROR message and continue with the WAN process.
if(dad_flag == 0 || route_flag == 0)
{
CcspTraceError(("%s %d dad_flag[%s] route_flag[%s] Failed \n", __FUNCTION__, __LINE__, dad_flag ? "SUCCESS" : "FAILED", route_flag ? "SUCCESS" : "FAILED"));
Expand Down Expand Up @@ -1754,7 +1813,7 @@ static int wan_setUpIPv6(WanMgr_IfaceSM_Controller_t * pWanIfaceCtrl)
* On a lease change the address is flushed and re-added, which restarts DAD;
* restarting sshd/dropbear while the address is still tentative makes the bind
* fail with "Cannot assign requested address", leaving reverse SSH IPv4-only. */
if (checkIpv6AddressIsReadyToUse(p_VirtIf) != RETURN_OK)
if (checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) != RETURN_OK)
{
CcspTraceError(("%s %d - IPv6 address not ready (DAD/route) on %s before restarting services\n",
__FUNCTION__, __LINE__, p_VirtIf->Name));
Expand Down Expand Up @@ -4185,7 +4244,7 @@ static eWanState_t wan_state_obtaining_ip_addresses(WanMgr_IfaceSM_Controller_t*
p_VirtIf->IP.Ipv6Changed = FALSE;
return WAN_STATE_OBTAINING_IP_ADDRESSES;
}
if (checkIpv6AddressIsReadyToUse(p_VirtIf) == RETURN_OK)
if (checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) == RETURN_OK)
{
return wan_transition_ipv6_up(pWanIfaceCtrl);
}
Expand Down Expand Up @@ -4256,7 +4315,7 @@ static eWanState_t wan_state_standby(WanMgr_IfaceSM_Controller_t* pWanIfaceCtrl)
}
p_VirtIf->IP.Ipv6Changed = FALSE;
}
if (checkIpv6AddressIsReadyToUse(p_VirtIf) == RETURN_OK)
if (checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) == RETURN_OK)
{
ret = wan_transition_ipv6_up(pWanIfaceCtrl);
CcspTraceInfo((" %s %d - IPv6 Address Assigned to Bridge Yet.\n", __FUNCTION__, __LINE__));
Expand Down Expand Up @@ -4365,7 +4424,7 @@ static eWanState_t wan_state_ipv4_leased(WanMgr_IfaceSM_Controller_t* pWanIfaceC
p_VirtIf->IP.Ipv6Changed = FALSE;
return WAN_STATE_IPV4_LEASED;
}
if (checkIpv6AddressIsReadyToUse(p_VirtIf) == RETURN_OK)
if (checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) == RETURN_OK)
{
return wan_transition_ipv6_up(pWanIfaceCtrl);
}
Expand Down Expand Up @@ -4473,7 +4532,7 @@ static eWanState_t wan_state_ipv6_leased(WanMgr_IfaceSM_Controller_t* pWanIfaceC
}
#if defined(FEATURE_MAPT) || defined(FEATURE_SUPPORT_MAPT_NAT46) || defined(FEATURE_MAPE)
else if (pInterface->Selection.Status == WAN_IFACE_ACTIVE &&
((p_VirtIf->EnableMAPT == TRUE && p_VirtIf->MAP.MaptStatus == WAN_IFACE_MAPT_STATE_UP && checkIpv6AddressIsReadyToUse(p_VirtIf) ==RETURN_OK)
((p_VirtIf->EnableMAPT == TRUE && p_VirtIf->MAP.MaptStatus == WAN_IFACE_MAPT_STATE_UP && checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) ==RETURN_OK)
|| (p_VirtIf->MAP.dhcp6cMAPparameters.mapType == MAP_TYPE_MAPE && p_VirtIf->Status == WAN_IFACE_STATUS_UP && p_VirtIf->MAP.MapeStatus == WAN_IFACE_MAPE_STATE_UP)))
{
CcspTraceInfo(("%s %d - calling wan_transition_map_up \n", __FUNCTION__, __LINE__));
Expand All @@ -4500,7 +4559,7 @@ static eWanState_t wan_state_ipv6_leased(WanMgr_IfaceSM_Controller_t* pWanIfaceC
{
if (p_VirtIf->DSLite.Status == WAN_IFACE_DSLITE_STATE_DOWN)
{
if (checkIpv6AddressIsReadyToUse(p_VirtIf) == RETURN_OK)
if (checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) == RETURN_OK)
{
return wan_transition_dslite_up(pWanIfaceCtrl);
}
Expand Down Expand Up @@ -4628,7 +4687,7 @@ static eWanState_t wan_state_dual_stack_active(WanMgr_IfaceSM_Controller_t* pWan
}
#if defined(FEATURE_MAPT) || defined(FEATURE_SUPPORT_MAPT_NAT46) || defined(FEATURE_MAPE)
else if (pInterface->Selection.Status == WAN_IFACE_ACTIVE &&
((p_VirtIf->EnableMAPT == TRUE && p_VirtIf->MAP.MaptStatus == WAN_IFACE_MAPT_STATE_UP && checkIpv6AddressIsReadyToUse(p_VirtIf) ==RETURN_OK)
((p_VirtIf->EnableMAPT == TRUE && p_VirtIf->MAP.MaptStatus == WAN_IFACE_MAPT_STATE_UP && checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) ==RETURN_OK)
|| (p_VirtIf->MAP.dhcp6cMAPparameters.mapType == MAP_TYPE_MAPE && p_VirtIf->Status == WAN_IFACE_STATUS_UP && p_VirtIf->MAP.MapeStatus == WAN_IFACE_MAPE_STATE_UP)))
{
CcspTraceInfo(("%s %d - calling wan_transition_map_up \n", __FUNCTION__, __LINE__));
Expand All @@ -4655,7 +4714,7 @@ static eWanState_t wan_state_dual_stack_active(WanMgr_IfaceSM_Controller_t* pWan
{
if (p_VirtIf->DSLite.Status == WAN_IFACE_DSLITE_STATE_DOWN)
{
if (checkIpv6AddressIsReadyToUse(p_VirtIf) == RETURN_OK)
if (checkIpv6AddressIsReadyToUse(p_VirtIf, pInterface->IfaceType) == RETURN_OK)
{
return wan_transition_dslite_up(pWanIfaceCtrl);
}
Expand Down
24 changes: 22 additions & 2 deletions source/WanManager/wanmgr_network_monitor.c
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Expand Up @@ -201,11 +201,13 @@ static ANSC_STATUS parse_addrattr(struct nlmsghdr *nlh)
{
ANSC_STATUS ret = ANSC_STATUS_FAILURE;
struct ifaddrmsg *ifa = NLMSG_DATA(nlh);
char ifname[IF_NAMESIZE],
ipv6_addr[INET6_ADDRSTRLEN];
char ifname[IF_NAMESIZE] = {0},
ipv6_addr[INET6_ADDRSTRLEN] = {0};
unsigned int prefix_length = 0,
pref_lifetime = 0,
valid_lifetime = 0;
/* ifa_flags only carries the low 8 bits, the IFA_FLAGS attribute below carries all 32 */
unsigned int addr_flags = ifa->ifa_flags;
IPv6NetLinkAddrEvent stAddrEvent;

//Allow only for Global Scope
Expand Down Expand Up @@ -245,8 +247,17 @@ static ANSC_STATUS parse_addrattr(struct nlmsghdr *nlh)
__FUNCTION__, __LINE__,
ci->ifa_prefered, ci->ifa_valid));
}
if (rta->rta_type == IFA_FLAGS) {
addr_flags = *(unsigned int *)RTA_DATA(rta);
}
}

CcspTraceInfo(("%s-%d [ADDR EVENT] flags=0x%08x%s%s%s%s\n", __FUNCTION__, __LINE__, addr_flags,
(addr_flags & IFA_F_TENTATIVE) ? " TENTATIVE" : "",
(addr_flags & IFA_F_DADFAILED) ? " DADFAILED" : "",
(addr_flags & IFA_F_DEPRECATED) ? " DEPRECATED" : "",
(addr_flags & IFA_F_PERMANENT) ? " PERMANENT" : ""));

if (nlh->nlmsg_type == RTM_NEWADDR)
{
memset(&stAddrEvent, 0, sizeof(IPv6NetLinkAddrEvent));
Expand All @@ -259,6 +270,15 @@ static ANSC_STATUS parse_addrattr(struct nlmsghdr *nlh)

CcspTraceInfo(("%s-%d [ADDR EVENT] RTM_NEWADDR (new/updated address) for '%s' interface, Info 'NEWADDR|%s|%u|%u|%u'\n", __FUNCTION__, __LINE__, ifname, ipv6_addr, prefix_length, pref_lifetime, valid_lifetime));
WanMgr_Handle_Dhcpv6_NetLink_Address_Event(&stAddrEvent);

/* The kernel reports a DAD failure as an RTM_NEWADDR carrying IFA_F_DADFAILED, not as a separate event.
* Recovery is handled by checkIpv6AddressIsReadyToUse() in the interface state machine, not here. */
if ((addr_flags & IFA_F_DADFAILED) && (ipv6_addr[0] != '\0'))
{
CcspTraceError(("%s-%d [ADDR EVENT] DAD FAILED for address %s/%u on '%s' interface, flags=0x%08x\n",
__FUNCTION__, __LINE__, ipv6_addr, prefix_length, ifname, addr_flags));
}

ret = ANSC_STATUS_SUCCESS;
}
else if (nlh->nlmsg_type == RTM_DELADDR)
Expand Down
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