Re: [PATCH] systemd: networkd: backport ipv4ll fixes from upstream

[Denys Dmytriyenko <denys@ti.com>]

Thanks, much appreciated!
I'll merge it to morty-next for testing.


On Mon, Apr 03, 2017 at 12:47:35PM -0500, Jason Reeder wrote:
> This commit adds three backported commits from upstream
> systemd that corrects ipv4ll bugs for compliance testing.
> 
> https://github.com/systemd/systemd/pull/5361
> https://github.com/systemd/systemd/pull/5589
> 
> Signed-off-by: Jason Reeder <jreeder@ti.com>
> ---
>  ...emd-network-ipv4ll-probe-conflict-counter.patch | 48 ++++++++++++++++++
>  ...network-sd-ipv4ll-Wrapper-to-restart-addr.patch | 53 +++++++++++++++++++
>  ...network-sd-ipv4ll-acquire-new-address-aft.patch | 59 ++++++++++++++++++++++
>  .../recipes-core/systemd/systemd_%.bbappend        |  3 ++
>  4 files changed, 163 insertions(+)
>  create mode 100644 meta-arago-distro/recipes-core/systemd/systemd/0001-libsystemd-network-ipv4ll-probe-conflict-counter.patch
>  create mode 100644 meta-arago-distro/recipes-core/systemd/systemd/0002-libsystemd-network-sd-ipv4ll-Wrapper-to-restart-addr.patch
>  create mode 100644 meta-arago-distro/recipes-core/systemd/systemd/0003-libsystemd-network-sd-ipv4ll-acquire-new-address-aft.patch
> 
> diff --git a/meta-arago-distro/recipes-core/systemd/systemd/0001-libsystemd-network-ipv4ll-probe-conflict-counter.patch b/meta-arago-distro/recipes-core/systemd/systemd/0001-libsystemd-network-ipv4ll-probe-conflict-counter.patch
> new file mode 100644
> index 0000000..557a297
> --- /dev/null
> +++ b/meta-arago-distro/recipes-core/systemd/systemd/0001-libsystemd-network-ipv4ll-probe-conflict-counter.patch
> @@ -0,0 +1,48 @@
> +From 1e47842a0144c501cc6fd7ccc7996761f3e32ea9 Mon Sep 17 00:00:00 2001
> +From: Jason Reeder <jasonreeder@gmail.com>
> +Date: Mon, 3 Apr 2017 12:07:17 -0500
> +Subject: [PATCH 1/3] libsystemd-network: ipv4ll probe conflict counter
> +
> +A bug exists where the conflict counter is cleared
> +regardless of whether or not the next probe attempt leads to
> +a successful address acquisition. This causes 'bursts' of
> +MAX_CONFLICTS probes followed by a delay of
> +RATE_LIMIT_INTERVAL instead of a single probe each
> +RATE_LIMIT_INTERVAL when beyond MAX_CONFLICTS.
> +
> +The conflict counter should only be cleared after an
> +address is successfully acquired. This commit achieves that
> +goal.
> +
> +From RFC3927:
> +A host should maintain a counter of the number of address
> +conflicts it has experienced in the process of trying to
> +acquire an address, and if the number of conflicts exceeds
> +MAX_CONFLICTS then the host MUST limit the rate at which it
> +probes for new addresses to no more than one new address per
> +RATE_LIMIT_INTERVAL.  This is to prevent catastrophic ARP
> +storms in pathological failure cases, such as a rogue host
> +that answers all ARP probes, causing legitimate hosts to go
> +into an infinite loop attempting to select a usable address.
> +
> +Signed-off-by: Jason Reeder <jasonreeder@gmail.com>
> +---
> + src/libsystemd-network/sd-ipv4acd.c | 2 --
> + 1 file changed, 2 deletions(-)
> +
> +diff --git a/src/libsystemd-network/sd-ipv4acd.c b/src/libsystemd-network/sd-ipv4acd.c
> +index cc7436d..97f37f2 100644
> +--- a/src/libsystemd-network/sd-ipv4acd.c
> ++++ b/src/libsystemd-network/sd-ipv4acd.c
> +@@ -249,8 +249,6 @@ static int ipv4acd_on_timeout(sd_event_source *s, uint64_t usec, void *userdata)
> +                         r = ipv4acd_set_next_wakeup(ll, RATE_LIMIT_INTERVAL, PROBE_WAIT);
> +                         if (r < 0)
> +                                 goto out;
> +-
> +-                        ll->conflict = 0;
> +                 } else {
> +                         r = ipv4acd_set_next_wakeup(ll, 0, PROBE_WAIT);
> +                         if (r < 0)
> +-- 
> +1.9.1
> +
> diff --git a/meta-arago-distro/recipes-core/systemd/systemd/0002-libsystemd-network-sd-ipv4ll-Wrapper-to-restart-addr.patch b/meta-arago-distro/recipes-core/systemd/systemd/0002-libsystemd-network-sd-ipv4ll-Wrapper-to-restart-addr.patch
> new file mode 100644
> index 0000000..8929f22
> --- /dev/null
> +++ b/meta-arago-distro/recipes-core/systemd/systemd/0002-libsystemd-network-sd-ipv4ll-Wrapper-to-restart-addr.patch
> @@ -0,0 +1,53 @@
> +From 920ece8950b1422c80cf3235626d78646c6cc88a Mon Sep 17 00:00:00 2001
> +From: Jason Reeder <jasonreeder@gmail.com>
> +Date: Mon, 3 Apr 2017 12:15:55 -0500
> +Subject: [PATCH 2/3] libsystemd-network: sd-ipv4ll: Wrapper to restart address
> + acquisition after conflict
> +
> +After an ipv4ll claimed address conflict occurs a new address needs
> +to be chosen and then the acquisition state machine needs to be
> +restarted.
> +
> +This commit adds a function (sd_ipv4ll_restart) that clears the
> +previously acquired address (ll->address) and then calls the existing
> +sd_ipv4ll_start function to choose the new address and start the
> +acquisition.
> +
> +Signed-off-by: Jason Reeder <jasonreeder@gmail.com>
> +---
> + src/libsystemd-network/sd-ipv4ll.c | 6 ++++++
> + src/systemd/sd-ipv4ll.h            | 1 +
> + 2 files changed, 7 insertions(+)
> +
> +diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
> +index 2a06418..2996516 100644
> +--- a/src/libsystemd-network/sd-ipv4ll.c
> ++++ b/src/libsystemd-network/sd-ipv4ll.c
> +@@ -289,6 +289,12 @@ static int ipv4ll_pick_address(sd_ipv4ll *ll) {
> +         return 0;
> + }
> + 
> ++int sd_ipv4ll_restart(sd_ipv4ll *ll) {
> ++        ll->address = 0;
> ++
> ++        return sd_ipv4ll_start(ll);
> ++}
> ++
> + int sd_ipv4ll_start(sd_ipv4ll *ll) {
> +         int r;
> + 
> +diff --git a/src/systemd/sd-ipv4ll.h b/src/systemd/sd-ipv4ll.h
> +index 6fa38a2..7c54979 100644
> +--- a/src/systemd/sd-ipv4ll.h
> ++++ b/src/systemd/sd-ipv4ll.h
> +@@ -47,6 +47,7 @@ int sd_ipv4ll_set_index(sd_ipv4ll *ll, int interface_index);
> + int sd_ipv4ll_set_address(sd_ipv4ll *ll, const struct in_addr *address);
> + int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, unsigned seed);
> + int sd_ipv4ll_is_running(sd_ipv4ll *ll);
> ++int sd_ipv4ll_restart(sd_ipv4ll *ll);
> + int sd_ipv4ll_start(sd_ipv4ll *ll);
> + int sd_ipv4ll_stop(sd_ipv4ll *ll);
> + sd_ipv4ll *sd_ipv4ll_ref(sd_ipv4ll *ll);
> +-- 
> +1.9.1
> +
> diff --git a/meta-arago-distro/recipes-core/systemd/systemd/0003-libsystemd-network-sd-ipv4ll-acquire-new-address-aft.patch b/meta-arago-distro/recipes-core/systemd/systemd/0003-libsystemd-network-sd-ipv4ll-acquire-new-address-aft.patch
> new file mode 100644
> index 0000000..9cb4908
> --- /dev/null
> +++ b/meta-arago-distro/recipes-core/systemd/systemd/0003-libsystemd-network-sd-ipv4ll-acquire-new-address-aft.patch
> @@ -0,0 +1,59 @@
> +From d3a4823b019a27bd9387216dcb94360bc432590e Mon Sep 17 00:00:00 2001
> +From: Jason Reeder <jasonreeder@gmail.com>
> +Date: Mon, 3 Apr 2017 12:16:58 -0500
> +Subject: [PATCH 3/3] libsystemd-network: sd-ipv4ll: acquire new address after
> + claimed address conflict
> +
> +If a conflict occurs on a claimed ipv4ll address, the device releases
> +the address and then does not attempt to acquire a new ipv4ll
> +address. According to RFC3927, releasing the address in this
> +situation is correct. However, this should be followed by an attempt
> +to configure a new ipv4ll address.
> +
> +This commit restarts the ipv4ll address acquisition state machine
> +after releasing the conflicting address.
> +
> +From RFC3927 Section 2.5 conflict defense method (b):
> +...
> +However, if this is not the first conflicting ARP packet the host has
> +seen, and the time recorded for the previous conflicting ARP packet is
> +recent, within DEFEND_INTERVAL seconds, then the host MUST immediately
> +cease using this address and configure a new IPv4 Link-Local address
> +as described above.
> +...
> +
> +Signed-off-by: Jason Reeder <jasonreeder@gmail.com>
> +---
> + src/network/networkd-ipv4ll.c | 10 ++++++++++
> + 1 file changed, 10 insertions(+)
> +
> +diff --git a/src/network/networkd-ipv4ll.c b/src/network/networkd-ipv4ll.c
> +index ae323d5..10f25f0 100644
> +--- a/src/network/networkd-ipv4ll.c
> ++++ b/src/network/networkd-ipv4ll.c
> +@@ -178,12 +178,22 @@ static void ipv4ll_handler(sd_ipv4ll *ll, int event, void *userdata) {
> + 
> +         switch(event) {
> +                 case SD_IPV4LL_EVENT_STOP:
> ++                        r = ipv4ll_address_lost(link);
> ++                        if (r < 0) {
> ++                                link_enter_failed(link);
> ++                                return;
> ++                        }
> ++                        break;
> +                 case SD_IPV4LL_EVENT_CONFLICT:
> +                         r = ipv4ll_address_lost(link);
> +                         if (r < 0) {
> +                                 link_enter_failed(link);
> +                                 return;
> +                         }
> ++
> ++                        r = sd_ipv4ll_restart(ll);
> ++                        if (r < 0)
> ++                                log_link_warning(link, "Could not acquire IPv4 link-local address");
> +                         break;
> +                 case SD_IPV4LL_EVENT_BIND:
> +                         r = ipv4ll_address_claimed(ll, link);
> +-- 
> +1.9.1
> +
> diff --git a/meta-arago-distro/recipes-core/systemd/systemd_%.bbappend b/meta-arago-distro/recipes-core/systemd/systemd_%.bbappend
> index 123d1ad..8fccdb5 100644
> --- a/meta-arago-distro/recipes-core/systemd/systemd_%.bbappend
> +++ b/meta-arago-distro/recipes-core/systemd/systemd_%.bbappend
> @@ -14,6 +14,9 @@ SRC_URI_append = " \
>      file://30-wlan.network \
>      file://60-usb.network \
>      file://sync-clocks.service \
> +    file://0001-libsystemd-network-ipv4ll-probe-conflict-counter.patch \
> +    file://0002-libsystemd-network-sd-ipv4ll-Wrapper-to-restart-addr.patch \
> +    file://0003-libsystemd-network-sd-ipv4ll-acquire-new-address-aft.patch \
>  "
>  
>  do_install_append() {
> -- 
> 1.9.1
> 
> _______________________________________________
> meta-arago mailing list
> meta-arago@arago-project.org
> http://arago-project.org/cgi-bin/mailman/listinfo/meta-arago