[PATCH][RFC] udhcp: add option to set CoS priority

Clément Péron peron.clem at gmail.com
Fri Jan 13 09:55:26 UTC 2023


Hi,


On Fri, 13 Jan 2023 at 10:48, Clément Péron <peron.clem at gmail.com> wrote:
>
> Some ISP, like the French ISP Orange uses DHCP messages with
> a CoS Priority of 6 otherwise they are not processed.
>
> Add an option to allow setting this property.

Please note, that I get this information from this blog post
https://www.lafois.com/tag/udhcp/

I'm still testing this patch and I'm unsure if we need to set the
priority for all the sockets.

I recovered a patch from Ubiquiti GPL archive where only

udhcp_send_raw_packet() set the priority and not udhcp_send_kernel_packet().

I'm not sure which one is correct.

Thanks for your help,
BR,
Clement

>
> Signed-off-by: Clément Péron <peron.clem at gmail.com>
> ---
>  networking/udhcp/Config.src  |  8 ++++++++
>  networking/udhcp/d6_dhcpc.c  |  6 ++++++
>  networking/udhcp/d6_packet.c | 14 ++++++++++++++
>  networking/udhcp/dhcpc.c     | 12 +++++++++++-
>  networking/udhcp/dhcpc.h     |  2 ++
>  networking/udhcp/packet.c    | 16 ++++++++++++++++
>  6 files changed, 57 insertions(+), 1 deletion(-)
>
> diff --git a/networking/udhcp/Config.src b/networking/udhcp/Config.src
> index 7ba7f48fc..49d5d7ef1 100644
> --- a/networking/udhcp/Config.src
> +++ b/networking/udhcp/Config.src
> @@ -137,6 +137,14 @@ config UDHCP_DEBUG
>         Bigger values result in bigger code. Levels above 1
>         are very verbose and useful for debugging only.
>
> +config FEATURE_UDHCPC_COS
> +       bool "Enable '-y priority' option for udhcpc"
> +       default n
> +       depends on UDHCPC || UDHCPC6
> +       help
> +       At the cost of ~300 bytes, enables -y priority option.
> +       This feature is typically not needed.
> +
>  config UDHCPC_SLACK_FOR_BUGGY_SERVERS
>         int "DHCP options slack buffer size"
>         default 80
> diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
> index cdd06188e..675914432 100644
> --- a/networking/udhcp/d6_dhcpc.c
> +++ b/networking/udhcp/d6_dhcpc.c
> @@ -129,6 +129,7 @@ static const char udhcpc6_longopts[] ALIGN1 =
>         )
>  ///    IF_FEATURE_UDHCPC_ARPING("arping\0"     No_argument       "a")
>         IF_FEATURE_UDHCP_PORT("client-port\0"   Required_argument "P")
> +       IF_FEATURE_UDHCPC_COS("cos\0"   Required_argument "y")
>         ;
>  #endif
>  /* Must match getopt32 option string order */
> @@ -1153,6 +1154,9 @@ static void client_background(void)
>  ////usage:     IF_FEATURE_UDHCPC_ARPING(
>  ////usage:     "\n     -a              Use arping to validate offered address"
>  ////usage:     )
> +//usage:       IF_FEATURE_UDHCPC_COS(
> +//usage:     "\n       -y PRIORITY     CoS value 0 .. 7, default 0"
> +//usage:       )
>  //usage:     "\n       -l              Send 'information request' instead of 'solicit'"
>  //usage:     "\n                       (used for servers which do not assign IPv6 addresses)"
>  //usage:     "\n       -r IPv6         Request this address ('no' to not request any IP)"
> @@ -1214,6 +1218,7 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
>                 USE_FOR_MMU("b")
>                 ///IF_FEATURE_UDHCPC_ARPING("a")
>                 IF_FEATURE_UDHCP_PORT("P:")
> +               IF_FEATURE_UDHCPC_COS("y:+")
>                 "v"
>                 "\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */
>                 , udhcpc6_longopts
> @@ -1223,6 +1228,7 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
>                 , &list_O
>                 , &list_x
>                 IF_FEATURE_UDHCP_PORT(, &str_P)
> +               IF_FEATURE_UDHCPC_COS(, &sk_prio)
>                 IF_UDHCP_VERBOSE(, &dhcp_verbose)
>         );
>         requested_ipv6 = NULL;
> diff --git a/networking/udhcp/d6_packet.c b/networking/udhcp/d6_packet.c
> index 142de9b43..425037ada 100644
> --- a/networking/udhcp/d6_packet.c
> +++ b/networking/udhcp/d6_packet.c
> @@ -68,6 +68,13 @@ int FAST_FUNC d6_send_raw_packet_from_client_data_ifindex(
>                 goto ret_msg;
>         }
>
> +       IF_FEATURE_UDHCPC_COS(
> +       if (sk_prio) {
> +               if (setsockopt_int(fd, SOL_SOCKET, SO_PRIORITY, sk_prio)) {
> +                       log1s("raw: SO_PRIORITY setsockopt() failed");
> +               }
> +       })
> +
>         memset(&dest_sll, 0, sizeof(dest_sll));
>         memset(&packet, 0, offsetof(struct ip6_udp_d6_packet, data));
>         packet.data = *d6_pkt; /* struct copy */
> @@ -153,6 +160,13 @@ int FAST_FUNC d6_send_kernel_packet_from_client_data_ifindex(
>         }
>         setsockopt_reuseaddr(fd);
>
> +       IF_FEATURE_UDHCPC_COS(
> +       if (sk_prio) {
> +               if (setsockopt_int(fd, SOL_SOCKET, SO_PRIORITY, sk_prio)) {
> +                       log1s("raw: SO_PRIORITY setsockopt() failed");
> +               }
> +       })
> +
>         memset(&sa, 0, sizeof(sa));
>         sa.sin6_family = AF_INET6;
>         sa.sin6_port = htons(source_port);
> diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
> index c757fb37c..7ff5ffde8 100644
> --- a/networking/udhcp/dhcpc.c
> +++ b/networking/udhcp/dhcpc.c
> @@ -1085,6 +1085,13 @@ static int udhcp_raw_socket(int ifindex)
>         }
>  #endif
>
> +IF_FEATURE_UDHCPC_COS(
> +       if (sk_prio) {
> +               if (setsockopt_int(fd, SOL_SOCKET, SO_PRIORITY, sk_prio)) {
> +                       log1s("raw: SO_PRIORITY setsockopt() failed");
> +               }
> +       })
> +
>         if (setsockopt_1(fd, SOL_PACKET, PACKET_AUXDATA) != 0) {
>                 if (errno != ENOPROTOOPT)
>                         log1s("can't set PACKET_AUXDATA on raw socket");
> @@ -1162,7 +1169,7 @@ static void client_background(void)
>  //usage:#endif
>  //usage:#define udhcpc_trivial_usage
>  //usage:       "[-fbq"IF_UDHCP_VERBOSE("v")"RB]"IF_FEATURE_UDHCPC_ARPING(" [-a[MSEC]]")" [-t N] [-T SEC] [-A SEC|-n]\n"
> -//usage:       "       [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-s PROG] [-p PIDFILE]\n"
> +//usage:       "       [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" "IF_FEATURE_UDHCPC_COS(" [-y PRIORITY]")" [-s PROG] [-p PIDFILE]\n"
>  //usage:       "       [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]..."
>  //usage:#define udhcpc_full_usage "\n"
>  //usage:     "\n       -i IFACE        Interface to use (default "CONFIG_UDHCPC_DEFAULT_INTERFACE")"
> @@ -1186,6 +1193,9 @@ static void client_background(void)
>  //usage:       IF_FEATURE_UDHCPC_ARPING(
>  //usage:     "\n       -a[MSEC]        Validate offered address with ARP ping"
>  //usage:       )
> +//usage:       IF_FEATURE_UDHCPC_COS(
> +//usage:     "\n       -y PRIORITY     CoS value 0 .. 7, default 0"
> +//usage:       )
>  //usage:     "\n       -r IP           Request this IP address"
>  //usage:     "\n       -o              Don't request any options (unless -O is given)"
>  //usage:     "\n       -O OPT          Request option OPT from server (cumulative)"
> diff --git a/networking/udhcp/dhcpc.h b/networking/udhcp/dhcpc.h
> index 19b054b32..c033eb13f 100644
> --- a/networking/udhcp/dhcpc.h
> +++ b/networking/udhcp/dhcpc.h
> @@ -7,6 +7,8 @@
>
>  PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
>
> +IF_FEATURE_UDHCPC_COS(extern int sk_prio;)
> +
>  struct client_data_t {
>         uint8_t client_mac[6];          /* Our mac address */
>         IF_FEATURE_UDHCP_PORT(uint16_t port;)
> diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c
> index 529978189..0babf451f 100644
> --- a/networking/udhcp/packet.c
> +++ b/networking/udhcp/packet.c
> @@ -12,6 +12,8 @@
>  #include <netinet/if_ether.h>
>  #include <netpacket/packet.h>
>
> +IF_FEATURE_UDHCPC_COS(int sk_prio;)
> +
>  #if ENABLE_UDHCPC || ENABLE_UDHCPD
>  void FAST_FUNC udhcp_init_header(struct dhcp_packet *packet, char type)
>  {
> @@ -121,6 +123,13 @@ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
>                 goto ret_msg;
>         }
>
> +       IF_FEATURE_UDHCPC_COS(
> +       if (sk_prio) {
> +               if (setsockopt_int(fd, SOL_SOCKET, SO_PRIORITY, sk_prio)) {
> +                       log1s("raw: SO_PRIORITY setsockopt() failed");
> +               }
> +       })
> +
>         memset(&dest_sll, 0, sizeof(dest_sll));
>         memset(&packet, 0, offsetof(struct ip_udp_dhcp_packet, data));
>         packet.data = *dhcp_pkt; /* struct copy */
> @@ -207,6 +216,13 @@ int FAST_FUNC udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
>         }
>         setsockopt_reuseaddr(fd);
>
> +       IF_FEATURE_UDHCPC_COS(
> +       if (sk_prio) {
> +               if (setsockopt_int(fd, SOL_SOCKET, SO_PRIORITY, sk_prio)) {
> +                       log1s("raw: SO_PRIORITY setsockopt() failed");
> +               }
> +       })
> +
>         /* If interface carrier goes down, unless we
>          * bind socket to a particular netdev, the packet
>          * can go out through another interface, eg. via
> --
> 2.34.1
>


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