[PATCH 2/2] iproute2: add support for link set

[Rui Salvaterra]

Hi, Ansuel,

On Thu, 20 Jan 2022 at 15:11, Ansuel Smith <ansuelsmth at gmail.com> wrote:
>
> Add support for link set useful to set CPU port for dsa drivers.
>
> Signed-off-by: Ansuel Smith <ansuelsmth at gmail.com>
> ---
>  ...-iplink_allow_to_change_iplink_value.patch | 94 +++++++++++++++++++
>  1 file changed, 94 insertions(+)
>  create mode 100644 package/network/utils/iproute2/patches/191-iplink_allow_to_change_iplink_value.patch
>
> diff --git a/package/network/utils/iproute2/patches/191-iplink_allow_to_change_iplink_value.patch b/package/network/utils/iproute2/patches/191-iplink_allow_to_change_iplink_value.patch
> new file mode 100644
> index 0000000000..1a8bad9119
> --- /dev/null
> +++ b/package/network/utils/iproute2/patches/191-iplink_allow_to_change_iplink_value.patch
> @@ -0,0 +1,94 @@
> +From:   Marek Behún <marek.behun at nic.cz>
> +Subject: [PATCH RFC iproute2-next] iplink: allow to change iplink value
> +Date:   Sat, 24 Aug 2019 04:42:51 +0200
> +
> +Allow to change the interface to which a given interface is linked to.
> +This is useful in the case of multi-CPU port DSA, for changing the CPU
> +port of a given user port.
> +
> +Signed-off-by: Marek Behún <marek.behun at nic.cz>
> +Cc: David Ahern <dsahern at gmail.com>
> +Cc: Stephen Hemminger <stephen at networkplumber.org>
> +Signed-off-by: Ansuel Smith <ansuelsmth at gmail.com>
> +---
> + ip/iplink.c           | 16 +++++-----------
> + man/man8/ip-link.8.in |  7 +++++++
> + 2 files changed, 12 insertions(+), 11 deletions(-)
> +
> +diff --git a/ip/iplink.c b/ip/iplink.c
> +index 212a0885..d52c0aaf 100644
> +--- a/ip/iplink.c
> ++++ b/ip/iplink.c
> +@@ -579,7 +579,6 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
> + {
> +       char *name = NULL;
> +       char *dev = NULL;
> +-      char *link = NULL;
> +       int ret, len;
> +       char abuf[32];
> +       int qlen = -1;
> +@@ -590,6 +589,7 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
> +       int numrxqueues = -1;
> +       int link_netnsid = -1;
> +       int index = 0;
> ++      int link = -1;
> +       int group = -1;
> +       int addr_len = 0;
> +
> +@@ -620,7 +620,10 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
> +                               invarg("Invalid \"index\" value", *argv);
> +               } else if (matches(*argv, "link") == 0) {
> +                       NEXT_ARG();
> +-                      link = *argv;
> ++                      link = ll_name_to_index(*argv);
> ++                      if (!link)
> ++                              return nodev(*argv);
> ++                      addattr32(&req->n, sizeof(*req), IFLA_LINK, link);
> +               } else if (matches(*argv, "address") == 0) {
> +                       NEXT_ARG();
> +                       addr_len = ll_addr_a2n(abuf, sizeof(abuf), *argv);
> +@@ -1004,15 +1007,6 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req, char **type)
> +                       exit(-1);
> +               }
> +
> +-              if (link) {
> +-                      int ifindex;
> +-
> +-                      ifindex = ll_name_to_index(link);
> +-                      if (!ifindex)
> +-                              return nodev(link);
> +-                      addattr32(&req->n, sizeof(*req), IFLA_LINK, ifindex);
> +-              }
> +-
> +               req->i.ifi_index = index;
> +       }
> +
> +diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
> +index a8ae72d2..800aed05 100644
> +--- a/man/man8/ip-link.8.in
> ++++ b/man/man8/ip-link.8.in
> +@@ -149,6 +149,9 @@ ip-link \- network device configuration
> + .br
> + .RB "[ " nomaster " ]"
> + .br
> ++.RB "[ " link
> ++.IR DEVICE " ]"
> ++.br
> + .RB "[ " vrf
> + .IR NAME " ]"
> + .br
> +@@ -2131,6 +2134,10 @@ set master device of the device (enslave device).
> + .BI nomaster
> + unset master device of the device (release device).
> +
> ++.TP
> ++.BI link " DEVICE"
> ++set device to which this device is linked to.
> ++
> + .TP
> + .BI addrgenmode " eui64|none|stable_secret|random"
> + set the IPv6 address generation mode
> +--
> +2.21.0
> +
> +
> --
> 2.30.2.windows.1
>

Nice, but we'll need to do the same for BusyBox's ip applet. Let's not
force everyone who needs multi-CPU DSA to install iproute2's ip just
for this case. ;)

Cheers,
Rui