[PATCH net-next] ipv6: don't generate link-local addr in random or privacy mode
From: Rocco Yue <hidden>
Date: 2021-11-09 07:00:25
In the 3GPP TS 29.061, here is a description as follows: "In order to avoid any conflict between the link-local address of the MS and that of the GGSN, the Interface-Identifier used by the MS to build its link-local address shall be assigned by the GGSN. The GGSN ensures the uniqueness of this Interface-Identifier. The MT shall then enforce the use of this Interface-Identifier by the TE" In other words, in the cellular network, GGSN determines whether to reply a solicited RA message by identifying the bottom 64 bits of the source address of the received RS message. Therefore, cellular network device's ipv6 link-local address should be set as the format of fe80::(GGSN assigned IID). To meet the above spec requirement, this patch adds two new addr_gen_mode: 1) IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA, this mode is suitable for cellular networks that support RFC7217. In this mode, the kernel doesn't generate a link-local address for the cellular NIC, and generates an ipv6 stable privacy global address after receiving the RA message. 2) IN6_ADDR_GEN_MODE_RANDOM_NO_LLA, in this mode, the kernel doesn't generate a link-local address for the cellular NIC, and will use the bottom 64 bits of the link-local address(same as the IID assigned by GGSN) to form an ipv6 global address after receiveing the RA message. Signed-off-by: Rocco Yue <redacted> --- include/uapi/linux/if_link.h | 2 ++ net/ipv6/addrconf.c | 22 ++++++++++++++++------ tools/include/uapi/linux/if_link.h | 2 ++ 3 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index eebd3894fe89..9c5695744c7d 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h@@ -428,6 +428,8 @@ enum in6_addr_gen_mode { IN6_ADDR_GEN_MODE_NONE, IN6_ADDR_GEN_MODE_STABLE_PRIVACY, IN6_ADDR_GEN_MODE_RANDOM, + IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA, + IN6_ADDR_GEN_MODE_RANDOM_NO_LLA, }; /* Bridge section */
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3445f8017430..0045de10f4b5 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c@@ -392,7 +392,8 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) timer_setup(&ndev->rs_timer, addrconf_rs_timer, 0); memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf)); - if (ndev->cnf.stable_secret.initialized) + if (ndev->cnf.stable_secret.initialized && + ndev->cnf.addr_gen_mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA) ndev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; ndev->cnf.mtu6 = dev->mtu;
@@ -2578,7 +2579,8 @@ static void manage_tempaddrs(struct inet6_dev *idev, static bool is_addr_mode_generate_stable(struct inet6_dev *idev) { return idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY || - idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM; + idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM || + idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA; } int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
@@ -3331,6 +3333,8 @@ static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route) 0, 0, GFP_KERNEL); break; case IN6_ADDR_GEN_MODE_NONE: + case IN6_ADDR_GEN_MODE_RANDOM_NO_LLA: + case IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA: default: /* will not add any link local address */ break;
@@ -5798,7 +5802,9 @@ static int check_addr_gen_mode(int mode) if (mode != IN6_ADDR_GEN_MODE_EUI64 && mode != IN6_ADDR_GEN_MODE_NONE && mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY && - mode != IN6_ADDR_GEN_MODE_RANDOM) + mode != IN6_ADDR_GEN_MODE_RANDOM && + mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA && + mode != IN6_ADDR_GEN_MODE_RANDOM_NO_LLA) return -EINVAL; return 1; }
@@ -6428,15 +6434,19 @@ static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write, for_each_netdev(net, dev) { struct inet6_dev *idev = __in6_dev_get(dev); - if (idev) { + if (idev && idev->cnf.addr_gen_mode != + IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA) { idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; } } } else { struct inet6_dev *idev = ctl->extra1; - - idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; + if (idev->cnf.addr_gen_mode != + IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA) { + idev->cnf.addr_gen_mode = + IN6_ADDR_GEN_MODE_STABLE_PRIVACY; + } } out:
diff --git a/tools/include/uapi/linux/if_link.h b/tools/include/uapi/linux/if_link.h
index b3610fdd1fee..fb69137aea89 100644
--- a/tools/include/uapi/linux/if_link.h
+++ b/tools/include/uapi/linux/if_link.h@@ -241,6 +241,8 @@ enum in6_addr_gen_mode { IN6_ADDR_GEN_MODE_NONE, IN6_ADDR_GEN_MODE_STABLE_PRIVACY, IN6_ADDR_GEN_MODE_RANDOM, + IN6_ADDR_GEN_MODE_STABLE_PRIVACY_NO_LLA, + IN6_ADDR_GEN_MODE_RANDOM_NO_LLA, }; /* Bridge section */
--
2.18.0