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correcting map-t mtu values #96

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4b68ba1
correcting map-t mtu values
Oct 1, 2025
92a5d29
correcting map-t mtu values
Oct 1, 2025
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28 changes: 22 additions & 6 deletions source/firewall/firewall.c
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Original file line number Diff line number Diff line change
Expand Up @@ -467,6 +467,8 @@ char cellular_ifname[32];
#define SYSEVENT_MAPT_PSID_VALUE "mapt_psid_value"
#define SYSEVENT_MAPT_PSID_LENGTH "mapt_psid_length"

#define MAPT_V4_MTU_SIZE 1472

BOOL isMAPTSet(void);
static int do_wan_nat_lan_clients_mapt(FILE *fp);
static char mapt_ip_address[BUFLEN_32];
Expand Down Expand Up @@ -1078,6 +1080,10 @@ int do_mapt_rules_v6(FILE *filter_fp)
return ret;
}

int getMaptMssClampVal()
{
return (MAPT_V4_MTU_SIZE - IPV4_TOTAL_HEADER_SIZE );
}
/*
==========================================================================
HUB4 MAPT Feature
Expand Down Expand Up @@ -1168,7 +1174,7 @@ int do_mapt_rules_v4(FILE *nat_fp, FILE *filter_fp, FILE *mangle_fp)
#if defined(NAT46_KERNEL_SUPPORT)
if (strcmp ( devicePartnerId, "sky-uk") == 0)
{
fprintf(mangle_fp, "-A PREROUTING -i %s -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss %d\n", NAT46_INTERFACE, NAT46_CLAMP_MSS);
fprintf(mangle_fp, "-A PREROUTING -i %s -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss %d\n", NAT46_INTERFACE, getMaptMssClampVal());
}
#endif

Expand All @@ -1183,15 +1189,15 @@ int do_mapt_rules_v4(FILE *nat_fp, FILE *filter_fp, FILE *mangle_fp)
/* UK MAPT Not connected MQTT broker. */
if (strcmp ( devicePartnerId, "sky-uk") == 0) {
fprintf(mangle_fp, "-A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o %s -j TCPMSS --set-mss %d"
"\n", NAT46_INTERFACE, NAT46_CLAMP_MSS);
"\n", NAT46_INTERFACE, getMaptMssClampVal());
}else {
// TCP MSS RULE - SKYH4-5123 - To improve IPv4 Downstream traffic performance
fprintf(mangle_fp, "-A FORWARD -p tcp --tcp-flags SYN,RST SYN -o %s -j TCPMSS --set-mss %d\n", NAT46_INTERFACE, NAT46_CLAMP_MSS);
fprintf(mangle_fp, "-A FORWARD -p tcp --tcp-flags SYN,RST SYN -o %s -j TCPMSS --set-mss %d\n", NAT46_INTERFACE, getMaptMssClampVal());
}
#elif defined (FEATURE_SUPPORT_MAPT_NAT46)
// RDKB-40515 - [MAP-T] Gw to NOC connectivity failure
fprintf(mangle_fp, "-A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o %s -j TCPMSS --set-mss %d"
"\n", NAT46_INTERFACE, NAT46_CLAMP_MSS);
"\n", NAT46_INTERFACE, getMaptMssClampVal());
#endif
if (mapt_config_ratio == 1) //config all
{
Expand Down Expand Up @@ -9976,8 +9982,18 @@ static int do_lan2wan_misc(FILE *filter_fp)

static void do_add_TCP_MSS_rules(FILE *mangle_fp)
{
fprintf(mangle_fp, "-I FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\n");
fprintf(mangle_fp, "-I OUTPUT -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\n");
FIREWALL_DEBUG("Entering do_add_TCP_MSS_rules\n");
if(isMAPTReady)
{
fprintf(mangle_fp, "-I FORWARD -o %s -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss %d\n", NAT46_INTERFACE, getMaptMssClampVal());
fprintf(mangle_fp, "-I OUTPUT -o %s -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --set-mss %d\n", NAT46_INTERFACE, getMaptMssClampVal());
}
else
{
fprintf(mangle_fp, "-I FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\n");
fprintf(mangle_fp, "-I OUTPUT -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu\n");
}

}

/*
Expand Down
3 changes: 3 additions & 0 deletions source/firewall/firewall.h
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Original file line number Diff line number Diff line change
Expand Up @@ -107,6 +107,9 @@ extern BOOL isMAPTReady;
#endif //IHC_FEATURE_ENABLED
#endif //_HUB4_PRODUCT_REQ_

#define IPV4_TOTAL_HEADER_SIZE 40
#define IPV6_TOTAL_HEADER_SIZE 60

#define PORT_SCAN_CHECK_CHAIN "PORT_SCAN_CHK"
#define PORT_SCAN_DROP_CHAIN "PORT_SCAN_DROP"

Expand Down
3 changes: 0 additions & 3 deletions source/firewall/firewall_ext.c
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Original file line number Diff line number Diff line change
Expand Up @@ -10,9 +10,6 @@
#include<errno.h>


#define IPV4_TOTAL_HEADER_SIZE 40
#define IPV6_TOTAL_HEADER_SIZE 60

#define MTU_SIZE 1500
#define PRIMARYLAN_L3NET "dmsb.MultiLAN.PrimaryLAN_l3net"
#define HOMESECURITY_L3NET "dmsb.MultiLAN.HomeSecurity_l3net"
Expand Down