From: Jakub Kicinski <k...@kernel.org> Right now CTRL_CMD_GETPOLICY can only dump the family-wide policy. Support dumping policy of a specific op.
v3: - rebase after per-op policy export and handle that v2: - make cmd U32, just in case. v1: - don't echo op in the output in a naive way, this should make it cleaner to extend the output format for dumping policies for all the commands at once in the future. Signed-off-by: Jakub Kicinski <k...@kernel.org> Link: https://lore.kernel.org/r/20201001225933.1373426-11-k...@kernel.org Signed-off-by: Johannes Berg <johannes.b...@intel.com> --- include/uapi/linux/genetlink.h | 1 + net/netlink/genetlink.c | 41 +++++++++++++++++++++++++++++----- 2 files changed, 37 insertions(+), 5 deletions(-) diff --git a/include/uapi/linux/genetlink.h b/include/uapi/linux/genetlink.h index bc9c98e84828..d83f214b4134 100644 --- a/include/uapi/linux/genetlink.h +++ b/include/uapi/linux/genetlink.h @@ -65,6 +65,7 @@ enum { CTRL_ATTR_MCAST_GROUPS, CTRL_ATTR_POLICY, CTRL_ATTR_OP_POLICY, + CTRL_ATTR_OP, __CTRL_ATTR_MAX, }; diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index eb916c44884f..c992424e4d63 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -123,7 +123,7 @@ static void genl_op_from_full(const struct genl_family *family, op->policy = family->policy; } -static int genl_get_cmd_full(u8 cmd, const struct genl_family *family, +static int genl_get_cmd_full(u32 cmd, const struct genl_family *family, struct genl_ops *op) { int i; @@ -152,7 +152,7 @@ static void genl_op_from_small(const struct genl_family *family, op->policy = family->policy; } -static int genl_get_cmd_small(u8 cmd, const struct genl_family *family, +static int genl_get_cmd_small(u32 cmd, const struct genl_family *family, struct genl_ops *op) { int i; @@ -166,7 +166,7 @@ static int genl_get_cmd_small(u8 cmd, const struct genl_family *family, return -ENOENT; } -static int genl_get_cmd(u8 cmd, const struct genl_family *family, +static int genl_get_cmd(u32 cmd, const struct genl_family *family, struct genl_ops *op) { if (!genl_get_cmd_full(cmd, family, op)) @@ -1114,14 +1114,17 @@ struct ctrl_dump_policy_ctx { struct netlink_policy_dump_state *state; const struct genl_family *rt; unsigned int opidx; + u32 op; u16 fam_id; - u8 policies:1; + u8 policies:1, + single_op:1; }; static const struct nla_policy ctrl_policy_policy[] = { [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, .len = GENL_NAMSIZ - 1 }, + [CTRL_ATTR_OP] = { .type = NLA_U32 }, }; static int ctrl_dumppolicy_start(struct netlink_callback *cb) @@ -1154,6 +1157,23 @@ static int ctrl_dumppolicy_start(struct netlink_callback *cb) ctx->rt = rt; + if (tb[CTRL_ATTR_OP]) { + ctx->single_op = true; + ctx->op = nla_get_u32(tb[CTRL_ATTR_OP]); + + err = genl_get_cmd(ctx->op, rt, &op); + if (err) { + NL_SET_BAD_ATTR(cb->extack, tb[CTRL_ATTR_OP]); + return err; + } + + if (!op.policy) + return -ENODATA; + + return netlink_policy_dump_add_policy(&ctx->state, op.policy, + op.maxattr); + } + for (i = 0; i < genl_get_cmd_cnt(rt); i++) { genl_get_cmd_by_index(i, rt, &op); @@ -1248,7 +1268,18 @@ static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) while (ctx->opidx < genl_get_cmd_cnt(ctx->rt)) { struct genl_ops op; - genl_get_cmd_by_index(ctx->opidx, ctx->rt, &op); + if (ctx->single_op) { + int err; + + err = genl_get_cmd(ctx->op, ctx->rt, &op); + if (WARN_ON(err)) + return skb->len; + + /* break out of the loop after this one */ + ctx->opidx = genl_get_cmd_cnt(ctx->rt); + } else { + genl_get_cmd_by_index(ctx->opidx, ctx->rt, &op); + } if (ctrl_dumppolicy_put_op(skb, cb, &op)) return skb->len; -- 2.26.2
