dscp: add option to set dscp value

Problem: odhcp6c doesn't support change of DSCP value.

Solution: Adapt odhcp6c to set socket option to change the DSCP value
for dhcpv6 packets.

Signed-off-by: Nicolas BESNARD <[email protected]>
Signed-off-by: Paul Donald <[email protected]>
Link: https://github.com/openwrt/odhcp6c/pull/106
Signed-off-by: Álvaro Fernández Rojas <[email protected]>

diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index 50b6f7bda189f7b3d96102b6bf938a2f610e644b..398592700ef71494d3716fa57cbdb5def009f4ff 100644 (file)
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -193,7 +193,7 @@ static char *dhcpv6_status_code_to_str(uint16_t code)
        return "Unknown";
 }
 
-int init_dhcpv6(const char *ifname, unsigned int options, int sk_prio, int sol_timeout)
+int init_dhcpv6(const char *ifname, unsigned int options, int sk_prio, int sol_timeout, unsigned int dscp)
 {
        client_options = options;
        dhcpv6_retx[DHCPV6_MSG_SOLICIT].max_timeo = sol_timeout;
@@ -287,6 +287,11 @@ int init_dhcpv6(const char *ifname, unsigned int options, int sk_prio, int sol_t
        if (setsockopt(sock, SOL_SOCKET, SO_PRIORITY, &sk_prio, sizeof(sk_prio)) < 0)
                goto failure;
 
+       val = dscp << 2;
+       if (setsockopt(sock, IPPROTO_IPV6, IPV6_TCLASS, &val, sizeof(val)) < 0) {
+               goto failure;
+       }
+
        struct sockaddr_in6 client_addr = { .sin6_family = AF_INET6,
                .sin6_port = htons(DHCPV6_CLIENT_PORT), .sin6_flowinfo = 0 };
 

diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index 8354820746131b8d0c9d01f7141af635edc0b8fe..f4399013036caa1a76951798819628b37f218785 100644 (file)
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -187,8 +187,9 @@ int main(_unused int argc, char* const argv[])
        unsigned int client_options = DHCPV6_CLIENT_FQDN | DHCPV6_ACCEPT_RECONFIGURE;
        unsigned int ra_options = RA_RDNSS_DEFAULT_LIFETIME;
        unsigned int ra_holdoff_interval = RA_MIN_ADV_INTERVAL;
+       unsigned int dscp = 0;
 
-       while ((c = getopt(argc, argv, "S::DN:V:P:FB:c:i:r:Ru:Ux:s:kK:t:m:Lhedp:fav")) != -1) {
+       while ((c = getopt(argc, argv, "S::DN:V:P:FB:c:i:r:Ru:Ux:s:kK:t:C:m:Lhedp:fav")) != -1) {
                switch (c) {
                case 'S':
                        allow_slaac_only = (optarg) ? atoi(optarg) : -1;
@@ -366,6 +367,14 @@ int main(_unused int argc, char* const argv[])
                        sol_timeout = atoi(optarg);
                        break;
 
+               case 'C':
+                       dscp = atoi(optarg);
+                       if (dscp > 63) {
+                               dscp = 0;
+                               syslog(LOG_ERR, "Invalid DSCP value, using default (0)");
+                       }
+                       break;
+
                case 'm':
                        ra_holdoff_interval = atoi(optarg);
                        break;
@@ -453,13 +462,13 @@ int main(_unused int argc, char* const argv[])
                }
        }
 
-    if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
-            init_dhcpv6(ifname, client_options, sk_prio, sol_timeout) ||
-            ra_init(ifname, &ifid, ra_options, ra_holdoff_interval) ||
-            script_init(script, ifname)) {
-        syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
-        return 4;
-     }
+       if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
+                       init_dhcpv6(ifname, client_options, sk_prio, sol_timeout, dscp) ||
+                       ra_init(ifname, &ifid, ra_options, ra_holdoff_interval) ||
+                       script_init(script, ifname)) {
+               syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
+               return 4;
+       }
 
     script_call("started", 0, false);
 
@@ -648,6 +657,7 @@ static int usage(void)
        "       -f              Don't send Client FQDN option\n"
        "       -k              Don't send a RELEASE when stopping\n"
        "       -K <sk-prio>    Set packet kernel priority (0)\n"
+       "       -C <dscp>       Set packet DSCP value (0)\n"
        "       -t <seconds>    Maximum timeout for DHCPv6-SOLICIT (120)\n"
        "       -m <seconds>    Minimum time between accepting RA updates (3)\n"
        "       -L              Ignore default lifetime for RDNSS records\n"

diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index 518193e5b5981eeb15c18d2cafd0347f2e25c975..8bba932522a2ba95027d379986e08103e4cf8fd1 100644 (file)
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -393,7 +393,7 @@ struct odhcp6c_opt {
        const char *str;
 };
 
-int init_dhcpv6(const char *ifname, unsigned int client_options, int sk_prio, int sol_timeout);
+int init_dhcpv6(const char *ifname, unsigned int client_options, int sk_prio, int sol_timeout, unsigned int dscp);
 int dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd, bool stateful_only);
 int dhcpv6_request(enum dhcpv6_msg type);
 int dhcpv6_poll_reconfigure(void);