From 6557461cd27843213ca19a7918bbaa8c3b7c5f5c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 4 Nov 2022 12:13:39 -0700 Subject: [PATCH] genetlink: add iterator for walking family ops Subsequent changes will expose split op structures to users, so walking the family ops with just an index will get harder. Add a structured iterator, convert the simple cases. Policy dumping needs more careful conversion. Signed-off-by: Jakub Kicinski Reviewed-by: Jacob Keller Signed-off-by: David S. Miller --- net/netlink/genetlink.c | 117 +++++++++++++++++++++++++++++++----------------- 1 file changed, 76 insertions(+), 41 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index ec32b60..06bf091 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -252,6 +252,57 @@ static void genl_get_cmd_by_index(unsigned int i, WARN_ON_ONCE(1); } +struct genl_op_iter { + const struct genl_family *family; + struct genl_split_ops doit; + struct genl_split_ops dumpit; + int i; + u32 cmd; + u8 flags; +}; + +static bool +genl_op_iter_init(const struct genl_family *family, struct genl_op_iter *iter) +{ + iter->family = family; + iter->i = 0; + + iter->flags = 0; + + return genl_get_cmd_cnt(iter->family); +} + +static bool genl_op_iter_next(struct genl_op_iter *iter) +{ + struct genl_ops op; + + if (iter->i >= genl_get_cmd_cnt(iter->family)) + return false; + + genl_get_cmd_by_index(iter->i, iter->family, &op); + iter->i++; + + genl_cmd_full_to_split(&iter->doit, iter->family, &op, GENL_CMD_CAP_DO); + genl_cmd_full_to_split(&iter->dumpit, iter->family, + &op, GENL_CMD_CAP_DUMP); + + iter->cmd = iter->doit.cmd | iter->dumpit.cmd; + iter->flags = iter->doit.flags | iter->dumpit.flags; + + return true; +} + +static void +genl_op_iter_copy(struct genl_op_iter *dst, struct genl_op_iter *src) +{ + *dst = *src; +} + +static unsigned int genl_op_iter_idx(struct genl_op_iter *iter) +{ + return iter->i; +} + static int genl_allocate_reserve_groups(int n_groups, int *first_id) { unsigned long *new_groups; @@ -419,25 +470,23 @@ static void genl_unregister_mc_groups(const struct genl_family *family) static int genl_validate_ops(const struct genl_family *family) { - int i, j; + struct genl_op_iter i, j; if (WARN_ON(family->n_ops && !family->ops) || WARN_ON(family->n_small_ops && !family->small_ops)) return -EINVAL; - for (i = 0; i < genl_get_cmd_cnt(family); i++) { - struct genl_ops op; - - genl_get_cmd_by_index(i, family, &op); - if (op.dumpit == NULL && op.doit == NULL) + for (genl_op_iter_init(family, &i); genl_op_iter_next(&i); ) { + if (!(i.flags & (GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP))) return -EINVAL; - if (WARN_ON(op.cmd >= family->resv_start_op && op.validate)) + + if (WARN_ON(i.cmd >= family->resv_start_op && + (i.doit.validate || i.dumpit.validate))) return -EINVAL; - for (j = i + 1; j < genl_get_cmd_cnt(family); j++) { - struct genl_ops op2; - genl_get_cmd_by_index(j, family, &op2); - if (op.cmd == op2.cmd) + genl_op_iter_copy(&j, &i); + while (genl_op_iter_next(&j)) { + if (i.cmd == j.cmd) return -EINVAL; } } @@ -917,6 +966,7 @@ static struct genl_family genl_ctrl; static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, u32 flags, struct sk_buff *skb, u8 cmd) { + struct genl_op_iter i; void *hdr; hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd); @@ -930,33 +980,26 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr)) goto nla_put_failure; - if (genl_get_cmd_cnt(family)) { + if (genl_op_iter_init(family, &i)) { struct nlattr *nla_ops; - int i; nla_ops = nla_nest_start_noflag(skb, CTRL_ATTR_OPS); if (nla_ops == NULL) goto nla_put_failure; - for (i = 0; i < genl_get_cmd_cnt(family); i++) { + while (genl_op_iter_next(&i)) { struct nlattr *nest; - struct genl_ops op; u32 op_flags; - genl_get_cmd_by_index(i, family, &op); - op_flags = op.flags; - if (op.dumpit) - op_flags |= GENL_CMD_CAP_DUMP; - if (op.doit) - op_flags |= GENL_CMD_CAP_DO; - if (op.policy) + op_flags = i.flags; + if (i.doit.policy || i.dumpit.policy) op_flags |= GENL_CMD_CAP_HASPOL; - nest = nla_nest_start_noflag(skb, i + 1); + nest = nla_nest_start_noflag(skb, genl_op_iter_idx(&i)); if (nest == NULL) goto nla_put_failure; - if (nla_put_u32(skb, CTRL_ATTR_OP_ID, op.cmd) || + if (nla_put_u32(skb, CTRL_ATTR_OP_ID, i.cmd) || nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags)) goto nla_put_failure; @@ -1229,8 +1272,8 @@ static int ctrl_dumppolicy_start(struct netlink_callback *cb) struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; struct nlattr **tb = info->attrs; const struct genl_family *rt; - struct genl_ops op; - int err, i; + struct genl_op_iter i; + int err; BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); @@ -1285,26 +1328,18 @@ static int ctrl_dumppolicy_start(struct netlink_callback *cb) return 0; } - for (i = 0; i < genl_get_cmd_cnt(rt); i++) { - struct genl_split_ops doit, dumpit; - - genl_get_cmd_by_index(i, rt, &op); - - genl_cmd_full_to_split(&doit, ctx->rt, &op, GENL_CMD_CAP_DO); - genl_cmd_full_to_split(&dumpit, ctx->rt, - &op, GENL_CMD_CAP_DUMP); - - if (doit.policy) { + for (genl_op_iter_init(rt, &i); genl_op_iter_next(&i); ) { + if (i.doit.policy) { err = netlink_policy_dump_add_policy(&ctx->state, - doit.policy, - doit.maxattr); + i.doit.policy, + i.doit.maxattr); if (err) goto err_free_state; } - if (dumpit.policy) { + if (i.dumpit.policy) { err = netlink_policy_dump_add_policy(&ctx->state, - dumpit.policy, - dumpit.maxattr); + i.dumpit.policy, + i.dumpit.maxattr); if (err) goto err_free_state; } -- 2.7.4