From: Tom Herbert <t...@herbertland.com>

Add a netlink interface to manage the TX TLV parameters. Managed
parameters include those for validating and sending TLVs being sent
such as alignment, TLV ordering, length limits, etc.

Signed-off-by: Tom Herbert <t...@herbertland.com>
Tested-by: Andrew Bowers <andrewx.bow...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
 include/net/ipeh.h         |  16 +++
 include/net/ipv6.h         |   1 +
 include/uapi/linux/in6.h   |   6 +
 include/uapi/linux/ipeh.h  |  29 +++++
 net/ipv6/exthdrs_common.c  | 238 +++++++++++++++++++++++++++++++++++++
 net/ipv6/exthdrs_options.c |  81 ++++++++++++-
 6 files changed, 369 insertions(+), 2 deletions(-)

diff --git a/include/net/ipeh.h b/include/net/ipeh.h
index de6d9d05f43e..8474a43f8a08 100644
--- a/include/net/ipeh.h
+++ b/include/net/ipeh.h
@@ -3,6 +3,7 @@
 #define _NET_IPEH_H
 
 #include <linux/skbuff.h>
+#include <net/genetlink.h>
 
 /*
  *     Parsing tlv encoded headers.
@@ -106,6 +107,21 @@ static inline int ipeh_tlv_unset_proc(struct 
tlv_param_table *tlv_param_table,
        return __ipeh_tlv_unset(tlv_param_table, type, false);
 }
 
+extern const struct nla_policy ipeh_tlv_nl_policy[];
+
+int ipeh_tlv_nl_cmd_set(struct tlv_param_table *tlv_param_table,
+                       struct genl_family *tlv_nl_family,
+                       struct sk_buff *skb, struct genl_info *info);
+int ipeh_tlv_nl_cmd_unset(struct tlv_param_table *tlv_param_table,
+                         struct genl_family *tlv_nl_family,
+                         struct sk_buff *skb, struct genl_info *info);
+int ipeh_tlv_nl_cmd_get(struct tlv_param_table *tlv_param_table,
+                       struct genl_family *tlv_nl_family,
+                       struct sk_buff *skb, struct genl_info *info);
+int ipeh_tlv_nl_dump(struct tlv_param_table *tlv_param_table,
+                    struct genl_family *tlv_nl_family,
+                    struct sk_buff *skb, struct netlink_callback *cb);
+
 /* ipeh_tlv_get_proc_by_type assumes rcu_read_lock is held */
 static inline struct tlv_proc *ipeh_tlv_get_proc_by_type(
                struct tlv_param_table *tlv_param_table, unsigned char type)
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 07bafad74e76..51517a16e528 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -14,6 +14,7 @@
 #include <linux/jhash.h>
 #include <linux/refcount.h>
 #include <linux/jump_label_ratelimit.h>
+#include <net/genetlink.h>
 #include <net/if_inet6.h>
 #include <net/ndisc.h>
 #include <net/flow.h>
diff --git a/include/uapi/linux/in6.h b/include/uapi/linux/in6.h
index 9f2273a08356..d5fe3d9a0b59 100644
--- a/include/uapi/linux/in6.h
+++ b/include/uapi/linux/in6.h
@@ -297,4 +297,10 @@ struct in6_flowlabel_req {
  * ...
  * MRT6_MAX
  */
+
+ /* NETLINK_GENERIC related info for IPv6 TLVs */
+
+#define IPV6_TLV_GENL_NAME             "ipv6-tlv"
+#define IPV6_TLV_GENL_VERSION          0x1
+
 #endif /* _UAPI_LINUX_IN6_H */
diff --git a/include/uapi/linux/ipeh.h b/include/uapi/linux/ipeh.h
index dbf0728ddce4..bac36a7faaae 100644
--- a/include/uapi/linux/ipeh.h
+++ b/include/uapi/linux/ipeh.h
@@ -21,4 +21,33 @@ enum {
        IPEH_TLV_PERM_MAX = IPEH_TLV_PERM_NO_CHECK
 };
 
+/* NETLINK_GENERIC related info for IP TLVs */
+
+enum {
+       IPEH_TLV_ATTR_UNSPEC,
+       IPEH_TLV_ATTR_TYPE,                     /* u8, > 1 */
+       IPEH_TLV_ATTR_ORDER,                    /* u16 */
+       IPEH_TLV_ATTR_ADMIN_PERM,               /* u8, perm value */
+       IPEH_TLV_ATTR_USER_PERM,                /* u8, perm value */
+       IPEH_TLV_ATTR_CLASS,                    /* u8, 3 bit flags */
+       IPEH_TLV_ATTR_ALIGN_MULT,               /* u8, 1 to 16 */
+       IPEH_TLV_ATTR_ALIGN_OFF,                /* u8, 0 to 15 */
+       IPEH_TLV_ATTR_MIN_DATA_LEN,             /* u8 (option data length) */
+       IPEH_TLV_ATTR_MAX_DATA_LEN,             /* u8 (option data length) */
+       IPEH_TLV_ATTR_DATA_LEN_MULT,            /* u8, 1 to 16 */
+       IPEH_TLV_ATTR_DATA_LEN_OFF,             /* u8, 0 to 15 */
+
+       __IPEH_TLV_ATTR_MAX,
+};
+
+#define IPEH_TLV_ATTR_MAX              (__IPEH_TLV_ATTR_MAX - 1)
+
+enum {
+       IPEH_TLV_CMD_SET,
+       IPEH_TLV_CMD_UNSET,
+       IPEH_TLV_CMD_GET,
+
+       __IPEH_TLV_CMD_MAX,
+};
+
 #endif /* _UAPI_LINUX_IPEH_H */
diff --git a/net/ipv6/exthdrs_common.c b/net/ipv6/exthdrs_common.c
index 791f6e4036c7..b44c6fd05f92 100644
--- a/net/ipv6/exthdrs_common.c
+++ b/net/ipv6/exthdrs_common.c
@@ -454,6 +454,244 @@ int __ipeh_tlv_unset(struct tlv_param_table 
*tlv_param_table,
 }
 EXPORT_SYMBOL(__ipeh_tlv_unset);
 
+const struct nla_policy ipeh_tlv_nl_policy[IPEH_TLV_ATTR_MAX + 1] = {
+       [IPEH_TLV_ATTR_TYPE] =          { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_ORDER] =         { .type = NLA_U16, },
+       [IPEH_TLV_ATTR_ADMIN_PERM] =    { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_USER_PERM] =     { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_CLASS] =         { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_ALIGN_MULT] =    { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_ALIGN_OFF] =     { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_MIN_DATA_LEN] =  { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_MAX_DATA_LEN] =  { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_DATA_LEN_OFF] =  { .type = NLA_U8, },
+       [IPEH_TLV_ATTR_DATA_LEN_MULT] = { .type = NLA_U8, },
+};
+EXPORT_SYMBOL(ipeh_tlv_nl_policy);
+
+int ipeh_tlv_nl_cmd_set(struct tlv_param_table *tlv_param_table,
+                       struct genl_family *tlv_nl_family,
+                       struct sk_buff *skb, struct genl_info *info)
+{
+       struct tlv_params new_params;
+       struct tlv_proc *tproc;
+       unsigned char type;
+       unsigned int v;
+       int retv = -EINVAL;
+
+       if (!info->attrs[IPEH_TLV_ATTR_TYPE])
+               return -EINVAL;
+
+       type = nla_get_u8(info->attrs[IPEH_TLV_ATTR_TYPE]);
+       if (type < 2)
+               return -EINVAL;
+
+       rcu_read_lock();
+
+       /* Base new parameters on existing ones */
+       tproc = ipeh_tlv_get_proc_by_type(tlv_param_table, type);
+       new_params = tproc->params;
+
+       if (info->attrs[IPEH_TLV_ATTR_ORDER]) {
+               v = nla_get_u16(info->attrs[IPEH_TLV_ATTR_ORDER]);
+               new_params.t.preferred_order = v;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_ADMIN_PERM]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_ADMIN_PERM]);
+               if (v > IPEH_TLV_PERM_MAX)
+                       goto out;
+               new_params.t.admin_perm = v;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_USER_PERM]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_USER_PERM]);
+               if (v > IPEH_TLV_PERM_MAX)
+                       goto out;
+               new_params.t.user_perm = v;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_CLASS]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_CLASS]);
+               if (!v || (v & ~IPEH_TLV_CLASS_FLAG_MASK))
+                       goto out;
+               new_params.t.class = v;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_ALIGN_MULT]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_ALIGN_MULT]);
+               if (v > 16 || v < 1)
+                       goto out;
+               new_params.t.align_mult = v - 1;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_ALIGN_OFF]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_ALIGN_OFF]);
+               if (v > 15)
+                       goto out;
+               new_params.t.align_off = v;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_MAX_DATA_LEN])
+               new_params.t.max_data_len =
+                   nla_get_u8(info->attrs[IPEH_TLV_ATTR_MAX_DATA_LEN]);
+
+       if (info->attrs[IPEH_TLV_ATTR_MIN_DATA_LEN])
+               new_params.t.min_data_len =
+                   nla_get_u8(info->attrs[IPEH_TLV_ATTR_MIN_DATA_LEN]);
+
+       if (info->attrs[IPEH_TLV_ATTR_DATA_LEN_MULT]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_DATA_LEN_MULT]);
+               if (v > 16 || v < 1)
+                       goto out;
+               new_params.t.data_len_mult = v - 1;
+       }
+
+       if (info->attrs[IPEH_TLV_ATTR_DATA_LEN_OFF]) {
+               v = nla_get_u8(info->attrs[IPEH_TLV_ATTR_DATA_LEN_OFF]);
+               if (v > 15)
+                       goto out;
+               new_params.t.data_len_off = v;
+       }
+
+       retv = ipeh_tlv_set_params(tlv_param_table, type, &new_params);
+
+out:
+       rcu_read_unlock();
+       return retv;
+}
+EXPORT_SYMBOL(ipeh_tlv_nl_cmd_set);
+
+int ipeh_tlv_nl_cmd_unset(struct tlv_param_table *tlv_param_table,
+                         struct genl_family *tlv_nl_family,
+                         struct sk_buff *skb, struct genl_info *info)
+{
+       unsigned char type;
+
+       if (!info->attrs[IPEH_TLV_ATTR_TYPE])
+               return -EINVAL;
+
+       type = nla_get_u8(info->attrs[IPEH_TLV_ATTR_TYPE]);
+       if (type < 2)
+               return -EINVAL;
+
+       return ipeh_tlv_unset_params(tlv_param_table, type);
+}
+EXPORT_SYMBOL(ipeh_tlv_nl_cmd_unset);
+
+static int tlv_fill_info(struct tlv_proc *tproc, unsigned char type,
+                        struct sk_buff *msg, bool admin)
+{
+       struct tlv_params *tp = &tproc->params;
+       int ret = 0;
+
+       if (nla_put_u8(msg, IPEH_TLV_ATTR_TYPE, type) ||
+           nla_put_u16(msg, IPEH_TLV_ATTR_ORDER, tp->t.preferred_order) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_USER_PERM, tp->t.user_perm) ||
+           (admin && nla_put_u8(msg, IPEH_TLV_ATTR_ADMIN_PERM,
+                                tp->t.admin_perm)) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_CLASS, tp->t.class) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_ALIGN_MULT, tp->t.align_mult + 1) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_ALIGN_OFF, tp->t.align_off) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_MIN_DATA_LEN, tp->t.min_data_len) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_MAX_DATA_LEN, tp->t.max_data_len) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_DATA_LEN_MULT,
+                      tp->t.data_len_mult + 1) ||
+           nla_put_u8(msg, IPEH_TLV_ATTR_DATA_LEN_OFF, tp->t.data_len_off))
+               ret = -1;
+
+       return ret;
+}
+
+static int tlv_dump_info(struct tlv_proc *tproc, unsigned char type,
+                        struct genl_family *tlv_nl_family, u32 portid,
+                        u32 seq, u32 flags, struct sk_buff *skb, u8 cmd,
+                        bool admin)
+{
+       void *hdr;
+
+       hdr = genlmsg_put(skb, portid, seq, tlv_nl_family, flags, cmd);
+       if (!hdr)
+               return -ENOMEM;
+
+       if (tlv_fill_info(tproc, type, skb, admin) < 0) {
+               genlmsg_cancel(skb, hdr);
+               return -EMSGSIZE;
+       }
+
+       genlmsg_end(skb, hdr);
+
+       return 0;
+}
+
+int ipeh_tlv_nl_cmd_get(struct tlv_param_table *tlv_param_table,
+                       struct genl_family *tlv_nl_family,
+                       struct sk_buff *skb, struct genl_info *info)
+{
+       struct tlv_proc *tproc;
+       struct sk_buff *msg;
+       unsigned char type;
+       int ret;
+
+       if (!info->attrs[IPEH_TLV_ATTR_TYPE])
+               return -EINVAL;
+
+       type = nla_get_u8(info->attrs[IPEH_TLV_ATTR_TYPE]);
+       if (type < 2)
+               return -EINVAL;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       rcu_read_lock();
+
+       tproc = ipeh_tlv_get_proc_by_type(tlv_param_table, type);
+       ret = tlv_dump_info(tproc, type, tlv_nl_family, info->snd_portid,
+                           info->snd_seq, 0, msg, info->genlhdr->cmd,
+                           netlink_capable(skb, CAP_NET_ADMIN));
+
+       rcu_read_unlock();
+
+       if (ret < 0) {
+               nlmsg_free(msg);
+               return ret;
+       }
+
+       return genlmsg_reply(msg, info);
+}
+EXPORT_SYMBOL(ipeh_tlv_nl_cmd_get);
+
+int ipeh_tlv_nl_dump(struct tlv_param_table *tlv_param_table,
+                    struct genl_family *tlv_nl_family,
+                    struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct tlv_proc *tproc;
+       int idx = 0, ret, i;
+
+       rcu_read_lock();
+
+       for (i = 2; i < 256; i++) {
+               if (idx++ < cb->args[0])
+                       continue;
+
+               tproc = ipeh_tlv_get_proc_by_type(tlv_param_table, i);
+               ret = tlv_dump_info(tproc, i, tlv_nl_family,
+                                   NETLINK_CB(cb->skb).portid,
+                                   cb->nlh->nlmsg_seq, NLM_F_MULTI,
+                                   skb, IPEH_TLV_CMD_GET,
+                                   netlink_capable(cb->skb, CAP_NET_ADMIN));
+               if (ret)
+                       break;
+       }
+
+       rcu_read_unlock();
+
+       cb->args[0] = idx;
+       return skb->len;
+}
+EXPORT_SYMBOL(ipeh_tlv_nl_dump);
+
 int ipeh_exthdrs_init(struct tlv_param_table *tlv_param_table,
                      const struct tlv_proc_init *tlv_init_params,
                      int num_init_params)
diff --git a/net/ipv6/exthdrs_options.c b/net/ipv6/exthdrs_options.c
index 3b50b584dd2d..c1889f67adb1 100644
--- a/net/ipv6/exthdrs_options.c
+++ b/net/ipv6/exthdrs_options.c
@@ -6,6 +6,7 @@
 #include <linux/socket.h>
 #include <linux/types.h>
 #include <net/calipso.h>
+#include <net/genetlink.h>
 #include <net/ipv6.h>
 #include <net/ip6_route.h>
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
@@ -253,13 +254,89 @@ static const struct tlv_proc_init tlv_ipv6_init_params[] 
__initconst = {
 struct tlv_param_table __rcu ipv6_tlv_param_table;
 EXPORT_SYMBOL(ipv6_tlv_param_table);
 
+static int ipv6_tlv_nl_cmd_set(struct sk_buff *skb, struct genl_info *info);
+static int ipv6_tlv_nl_cmd_unset(struct sk_buff *skb, struct genl_info *info);
+static int ipv6_tlv_nl_cmd_get(struct sk_buff *skb, struct genl_info *info);
+static int ipv6_tlv_nl_dump(struct sk_buff *skb, struct netlink_callback *cb);
+
+static const struct genl_ops ipv6_tlv_nl_ops[] = {
+{
+       .cmd = IPEH_TLV_CMD_SET,
+       .doit = ipv6_tlv_nl_cmd_set,
+       .flags = GENL_ADMIN_PERM,
+},
+{
+       .cmd = IPEH_TLV_CMD_UNSET,
+       .doit = ipv6_tlv_nl_cmd_unset,
+       .flags = GENL_ADMIN_PERM,
+},
+{
+       .cmd = IPEH_TLV_CMD_GET,
+       .doit = ipv6_tlv_nl_cmd_get,
+       .dumpit = ipv6_tlv_nl_dump,
+},
+};
+
+struct genl_family ipv6_tlv_nl_family __ro_after_init = {
+       .hdrsize        = 0,
+       .name           = IPV6_TLV_GENL_NAME,
+       .version        = IPV6_TLV_GENL_VERSION,
+       .maxattr        = IPEH_TLV_ATTR_MAX,
+       .policy         = ipeh_tlv_nl_policy,
+       .netnsok        = true,
+       .parallel_ops   = true,
+       .ops            = ipv6_tlv_nl_ops,
+       .n_ops          = ARRAY_SIZE(ipv6_tlv_nl_ops),
+       .module         = THIS_MODULE,
+};
+
+static int ipv6_tlv_nl_cmd_set(struct sk_buff *skb, struct genl_info *info)
+{
+       return ipeh_tlv_nl_cmd_set(&ipv6_tlv_param_table, &ipv6_tlv_nl_family,
+                                  skb, info);
+}
+
+static int ipv6_tlv_nl_cmd_unset(struct sk_buff *skb, struct genl_info *info)
+{
+       return ipeh_tlv_nl_cmd_unset(&ipv6_tlv_param_table, &ipv6_tlv_nl_family,
+                                    skb, info);
+}
+
+static int ipv6_tlv_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
+{
+       return ipeh_tlv_nl_cmd_get(&ipv6_tlv_param_table, &ipv6_tlv_nl_family,
+                                  skb, info);
+}
+
+static int ipv6_tlv_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       return ipeh_tlv_nl_dump(&ipv6_tlv_param_table, &ipv6_tlv_nl_family,
+                               skb, cb);
+}
+
 int __init ipv6_exthdrs_options_init(void)
 {
-       return ipeh_exthdrs_init(&ipv6_tlv_param_table, tlv_ipv6_init_params,
-                                ARRAY_SIZE(tlv_ipv6_init_params));
+       int err;
+
+       err = genl_register_family(&ipv6_tlv_nl_family);
+       if (err)
+               goto genl_fail;
+
+       ipeh_exthdrs_init(&ipv6_tlv_param_table, tlv_ipv6_init_params,
+                         ARRAY_SIZE(tlv_ipv6_init_params));
+       if (err)
+               goto ipv6_fail;
+
+       return 0;
+
+ipv6_fail:
+       genl_unregister_family(&ipv6_tlv_nl_family);
+genl_fail:
+       return err;
 }
 
 void ipv6_exthdrs_options_exit(void)
 {
        ipeh_exthdrs_fini(&ipv6_tlv_param_table);
+       genl_unregister_family(&ipv6_tlv_nl_family);
 }
-- 
2.21.0

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