From d35a00b8e33dab7385f724e713ae71c8be0a49f4 Mon Sep 17 00:00:00 2001 From: Felix Jia Date: Thu, 26 Jan 2017 16:59:17 +1300 Subject: [PATCH] net/ipv6: allow sysctl to change link-local address generation mode The address generation mode for IPv6 link-local can only be configured by netlink messages. This patch adds the ability to change the address generation mode via sysctl. v1 -> v2 Removed the rtnl lock and switch to use RCU lock to iterate through the netdev list. v2 -> v3 Removed the addrgenmode variable from the idev structure and use the systcl storage for the flag. Simplifed the logic for sysctl handling by removing the supported for all operation. Added support for more types of tunnel interfaces for link-local address generation. Based the patches from net-next. v3 -> v4 Removed unnecessary whitespace changes. Signed-off-by: Felix Jia Signed-off-by: David S. Miller --- include/linux/ipv6.h | 1 + include/net/if_inet6.h | 1 - include/uapi/linux/ipv6.h | 1 + net/ipv6/addrconf.c | 104 ++++++++++++++++++++++++++++++-------- 4 files changed, 86 insertions(+), 21 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 671d014e6429..71be5b330d21 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -69,6 +69,7 @@ struct ipv6_devconf { __s32 seg6_require_hmac; #endif __u32 enhanced_dad; + __u32 addr_gen_mode; struct ctl_table_header *sysctl_header; }; diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index 0fa4c324b713..f656f9051aca 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -205,7 +205,6 @@ struct inet6_dev { __s32 rs_interval; /* in jiffies */ __u8 rs_probes; - __u8 addr_gen_mode; unsigned long tstamp; /* ipv6InterfaceTable update timestamp */ struct rcu_head rcu; }; diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index eaf65dc82e22..8ef9e75e004e 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -182,6 +182,7 @@ enum { DEVCONF_SEG6_ENABLED, DEVCONF_SEG6_REQUIRE_HMAC, DEVCONF_ENHANCED_DAD, + DEVCONF_ADDR_GEN_MODE, DEVCONF_MAX }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index ac9bd5620f81..e35259dd17ba 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -243,6 +243,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { .seg6_require_hmac = 0, #endif .enhanced_dad = 1, + .addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64, }; static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { @@ -294,6 +295,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { .seg6_require_hmac = 0, #endif .enhanced_dad = 1, + .addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64, }; /* Check if a valid qdisc is available */ @@ -386,9 +388,9 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf)); if (ndev->cnf.stable_secret.initialized) - ndev->addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; + ndev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; else - ndev->addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64; + ndev->cnf.addr_gen_mode = ipv6_devconf_dflt.addr_gen_mode; ndev->cnf.mtu6 = dev->mtu; ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl); @@ -2387,8 +2389,8 @@ static void manage_tempaddrs(struct inet6_dev *idev, static bool is_addr_mode_generate_stable(struct inet6_dev *idev) { - return idev->addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY || - idev->addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM; + return idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY || + idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM; } int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev, @@ -3152,7 +3154,7 @@ static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route) ipv6_addr_set(&addr, htonl(0xFE800000), 0, 0, 0); - switch (idev->addr_gen_mode) { + switch (idev->cnf.addr_gen_mode) { case IN6_ADDR_GEN_MODE_RANDOM: ipv6_gen_mode_random_init(idev); /* fallthrough */ @@ -3204,8 +3206,8 @@ static void addrconf_dev_config(struct net_device *dev) /* this device type has no EUI support */ if (dev->type == ARPHRD_NONE && - idev->addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64) - idev->addr_gen_mode = IN6_ADDR_GEN_MODE_RANDOM; + idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64) + idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_RANDOM; addrconf_addr_gen(idev, false); } @@ -4982,6 +4984,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_SEG6_REQUIRE_HMAC] = cnf->seg6_require_hmac; #endif array[DEVCONF_ENHANCED_DAD] = cnf->enhanced_dad; + array[DEVCONF_ADDR_GEN_MODE] = cnf->addr_gen_mode; } static inline size_t inet6_ifla6_size(void) @@ -5093,7 +5096,7 @@ static int inet6_fill_ifla6_attrs(struct sk_buff *skb, struct inet6_dev *idev, if (!nla) goto nla_put_failure; - if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->addr_gen_mode)) + if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->cnf.addr_gen_mode)) goto nla_put_failure; read_lock_bh(&idev->lock); @@ -5211,6 +5214,26 @@ static int inet6_validate_link_af(const struct net_device *dev, return nla_parse_nested(tb, IFLA_INET6_MAX, nla, inet6_af_policy); } +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) + return -EINVAL; + return 1; +} + +static int check_stable_privacy(struct inet6_dev *idev, struct net *net, + int mode) +{ + if (mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY && + !idev->cnf.stable_secret.initialized && + !net->ipv6.devconf_dflt->stable_secret.initialized) + return -EINVAL; + return 1; +} + static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla) { int err = -EINVAL; @@ -5232,18 +5255,11 @@ static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla) if (tb[IFLA_INET6_ADDR_GEN_MODE]) { u8 mode = nla_get_u8(tb[IFLA_INET6_ADDR_GEN_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) + if (check_addr_gen_mode(mode) < 0 || + check_stable_privacy(idev, dev_net(dev), mode) < 0) return -EINVAL; - if (mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY && - !idev->cnf.stable_secret.initialized && - !dev_net(dev)->ipv6.devconf_dflt->stable_secret.initialized) - return -EINVAL; - - idev->addr_gen_mode = mode; + idev->cnf.addr_gen_mode = mode; err = 0; } @@ -5652,6 +5668,47 @@ int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write, return ret; } +static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int ret = 0; + int new_val; + struct inet6_dev *idev = (struct inet6_dev *)ctl->extra1; + struct net *net = (struct net *)ctl->extra2; + + ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + + if (write) { + new_val = *((int *)ctl->data); + + if (check_addr_gen_mode(new_val) < 0) + return -EINVAL; + + /* request for default */ + if (&net->ipv6.devconf_dflt->addr_gen_mode == ctl->data) { + ipv6_devconf_dflt.addr_gen_mode = new_val; + + /* request for individual net device */ + } else { + if (!idev) + return ret; + + if (check_stable_privacy(idev, net, new_val) < 0) + return -EINVAL; + + if (idev->cnf.addr_gen_mode != new_val) { + idev->cnf.addr_gen_mode = new_val; + rtnl_lock(); + addrconf_dev_config(idev->dev); + rtnl_unlock(); + } + } + } + + return ret; +} + static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos) @@ -5702,14 +5759,14 @@ static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write, struct inet6_dev *idev = __in6_dev_get(dev); if (idev) { - idev->addr_gen_mode = + idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; } } } else { struct inet6_dev *idev = ctl->extra1; - idev->addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; + idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY; } out: @@ -6096,6 +6153,13 @@ static const struct ctl_table addrconf_sysctl[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "addr_gen_mode", + .data = &ipv6_devconf.addr_gen_mode, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = addrconf_sysctl_addr_gen_mode, + }, { /* sentinel */ }