diff options
Diffstat (limited to 'net/netlink')
| -rw-r--r-- | net/netlink/af_netlink.c | 68 | ||||
| -rw-r--r-- | net/netlink/genetlink.c | 377 | ||||
| -rw-r--r-- | net/netlink/policy.c | 288 |
3 files changed, 564 insertions, 169 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index d2d1448274f5..daca50d6bb12 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -848,7 +848,7 @@ retry: * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the - * message has has the capability @cap in the user namespace @user_ns. + * message has the capability @cap in the user namespace @user_ns. */ bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, struct user_namespace *user_ns, int cap) @@ -867,7 +867,7 @@ EXPORT_SYMBOL(__netlink_ns_capable); * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the - * message has has the capability @cap in the user namespace @user_ns. + * message has the capability @cap in the user namespace @user_ns. */ bool netlink_ns_capable(const struct sk_buff *skb, struct user_namespace *user_ns, int cap) @@ -883,7 +883,7 @@ EXPORT_SYMBOL(netlink_ns_capable); * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the - * message has has the capability @cap in all user namespaces. + * message has the capability @cap in all user namespaces. */ bool netlink_capable(const struct sk_buff *skb, int cap) { @@ -898,7 +898,7 @@ EXPORT_SYMBOL(netlink_capable); * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the - * message has has the capability @cap over the network namespace of + * message has the capability @cap over the network namespace of * the socket we received the message from. */ bool netlink_net_capable(const struct sk_buff *skb, int cap) @@ -1853,7 +1853,7 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) struct scm_cookie scm; u32 netlink_skb_flags = 0; - if (msg->msg_flags&MSG_OOB) + if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; err = scm_send(sock, msg, &scm, true); @@ -1916,7 +1916,7 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) refcount_inc(&skb->users); netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); } - err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); + err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags & MSG_DONTWAIT); out: scm_destroy(&scm); @@ -1929,12 +1929,12 @@ static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, struct scm_cookie scm; struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); - int noblock = flags&MSG_DONTWAIT; + int noblock = flags & MSG_DONTWAIT; size_t copied; struct sk_buff *skb, *data_skb; int err, ret; - if (flags&MSG_OOB) + if (flags & MSG_OOB) return -EOPNOTSUPP; copied = 0; @@ -2186,13 +2186,35 @@ EXPORT_SYMBOL(__nlmsg_put); * It would be better to create kernel thread. */ +static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb, + struct netlink_callback *cb, + struct netlink_ext_ack *extack) +{ + struct nlmsghdr *nlh; + + nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno), + NLM_F_MULTI | cb->answer_flags); + if (WARN_ON(!nlh)) + return -ENOBUFS; + + nl_dump_check_consistent(cb, nlh); + memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); + + if (extack->_msg && nlk->flags & NETLINK_F_EXT_ACK) { + nlh->nlmsg_flags |= NLM_F_ACK_TLVS; + if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)) + nlmsg_end(skb, nlh); + } + + return 0; +} + static int netlink_dump(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); struct netlink_ext_ack extack = {}; struct netlink_callback *cb; struct sk_buff *skb = NULL; - struct nlmsghdr *nlh; struct module *module; int err = -ENOBUFS; int alloc_min_size; @@ -2258,22 +2280,19 @@ static int netlink_dump(struct sock *sk) return 0; } - nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, - sizeof(nlk->dump_done_errno), - NLM_F_MULTI | cb->answer_flags); - if (WARN_ON(!nlh)) + if (netlink_dump_done(nlk, skb, cb, &extack)) goto errout_skb; - nl_dump_check_consistent(cb, nlh); - - memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, - sizeof(nlk->dump_done_errno)); - - if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) { - nlh->nlmsg_flags |= NLM_F_ACK_TLVS; - if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg)) - nlmsg_end(skb, nlh); +#ifdef CONFIG_COMPAT_NETLINK_MESSAGES + /* frag_list skb's data is used for compat tasks + * and the regular skb's data for normal (non-compat) tasks. + * See netlink_recvmsg(). + */ + if (unlikely(skb_shinfo(skb)->frag_list)) { + if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, &extack)) + goto errout_skb; } +#endif if (sk_filter(sk, skb)) kfree_skb(skb); @@ -2401,6 +2420,8 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, tlvlen += nla_total_size(sizeof(u32)); if (nlk_has_extack && extack && extack->cookie_len) tlvlen += nla_total_size(extack->cookie_len); + if (err && nlk_has_extack && extack && extack->policy) + tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); if (tlvlen) flags |= NLM_F_ACK_TLVS; @@ -2433,6 +2454,9 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, if (extack->cookie_len) WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, extack->cookie_len, extack->cookie)); + if (extack->policy) + netlink_policy_dump_write_attr(skb, extack->policy, + NLMSGERR_ATTR_POLICY); } nlmsg_end(skb, rep); diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index c4b4d3376227..c992424e4d63 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -107,16 +107,83 @@ static const struct genl_family *genl_family_find_byname(char *name) return NULL; } -static const struct genl_ops *genl_get_cmd(u8 cmd, - const struct genl_family *family) +static int genl_get_cmd_cnt(const struct genl_family *family) +{ + return family->n_ops + family->n_small_ops; +} + +static void genl_op_from_full(const struct genl_family *family, + unsigned int i, struct genl_ops *op) +{ + *op = family->ops[i]; + + if (!op->maxattr) + op->maxattr = family->maxattr; + if (!op->policy) + op->policy = family->policy; +} + +static int genl_get_cmd_full(u32 cmd, const struct genl_family *family, + struct genl_ops *op) { int i; for (i = 0; i < family->n_ops; i++) - if (family->ops[i].cmd == cmd) - return &family->ops[i]; + if (family->ops[i].cmd == cmd) { + genl_op_from_full(family, i, op); + return 0; + } - return NULL; + return -ENOENT; +} + +static void genl_op_from_small(const struct genl_family *family, + unsigned int i, struct genl_ops *op) +{ + memset(op, 0, sizeof(*op)); + op->doit = family->small_ops[i].doit; + op->dumpit = family->small_ops[i].dumpit; + op->cmd = family->small_ops[i].cmd; + op->internal_flags = family->small_ops[i].internal_flags; + op->flags = family->small_ops[i].flags; + op->validate = family->small_ops[i].validate; + + op->maxattr = family->maxattr; + op->policy = family->policy; +} + +static int genl_get_cmd_small(u32 cmd, const struct genl_family *family, + struct genl_ops *op) +{ + int i; + + for (i = 0; i < family->n_small_ops; i++) + if (family->small_ops[i].cmd == cmd) { + genl_op_from_small(family, i, op); + return 0; + } + + return -ENOENT; +} + +static int genl_get_cmd(u32 cmd, const struct genl_family *family, + struct genl_ops *op) +{ + if (!genl_get_cmd_full(cmd, family, op)) + return 0; + return genl_get_cmd_small(cmd, family, op); +} + +static void genl_get_cmd_by_index(unsigned int i, + const struct genl_family *family, + struct genl_ops *op) +{ + if (i < family->n_ops) + genl_op_from_full(family, i, op); + else if (i < family->n_ops + family->n_small_ops) + genl_op_from_small(family, i - family->n_ops, op); + else + WARN_ON_ONCE(1); } static int genl_allocate_reserve_groups(int n_groups, int *first_id) @@ -222,7 +289,7 @@ static int genl_validate_assign_mc_groups(struct genl_family *family) family->mcgrp_offset = first_id; - /* if still initializing, can't and don't need to to realloc bitmaps */ + /* if still initializing, can't and don't need to realloc bitmaps */ if (!init_net.genl_sock) return 0; @@ -286,22 +353,25 @@ static void genl_unregister_mc_groups(const struct genl_family *family) static int genl_validate_ops(const struct genl_family *family) { - const struct genl_ops *ops = family->ops; - unsigned int n_ops = family->n_ops; int i, j; - if (WARN_ON(n_ops && !ops)) + if (WARN_ON(family->n_ops && !family->ops) || + WARN_ON(family->n_small_ops && !family->small_ops)) return -EINVAL; - if (!n_ops) - return 0; + for (i = 0; i < genl_get_cmd_cnt(family); i++) { + struct genl_ops op; - for (i = 0; i < n_ops; i++) { - if (ops[i].dumpit == NULL && ops[i].doit == NULL) + genl_get_cmd_by_index(i, family, &op); + if (op.dumpit == NULL && op.doit == NULL) return -EINVAL; - for (j = i + 1; j < n_ops; j++) - if (ops[i].cmd == ops[j].cmd) + 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) return -EINVAL; + } } return 0; @@ -467,16 +537,16 @@ genl_family_rcv_msg_attrs_parse(const struct genl_family *family, struct nlattr **attrbuf; int err; - if (!family->maxattr) + if (!ops->maxattr) return NULL; - attrbuf = kmalloc_array(family->maxattr + 1, + attrbuf = kmalloc_array(ops->maxattr + 1, sizeof(struct nlattr *), GFP_KERNEL); if (!attrbuf) return ERR_PTR(-ENOMEM); - err = __nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr, - family->policy, validate, extack); + err = __nlmsg_parse(nlh, hdrlen, attrbuf, ops->maxattr, ops->policy, + validate, extack); if (err) { kfree(attrbuf); return ERR_PTR(err); @@ -524,7 +594,7 @@ no_attrs: return -ENOMEM; } info->family = ctx->family; - info->ops = ops; + info->op = *ops; info->attrs = attrs; cb->data = info; @@ -546,7 +616,7 @@ no_attrs: static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { - const struct genl_ops *ops = genl_dumpit_info(cb)->ops; + const struct genl_ops *ops = &genl_dumpit_info(cb)->op; int rc; genl_lock(); @@ -558,7 +628,7 @@ static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) static int genl_lock_done(struct netlink_callback *cb) { const struct genl_dumpit_info *info = genl_dumpit_info(cb); - const struct genl_ops *ops = info->ops; + const struct genl_ops *ops = &info->op; int rc = 0; if (ops->done) { @@ -574,7 +644,7 @@ static int genl_lock_done(struct netlink_callback *cb) static int genl_parallel_done(struct netlink_callback *cb) { const struct genl_dumpit_info *info = genl_dumpit_info(cb); - const struct genl_ops *ops = info->ops; + const struct genl_ops *ops = &info->op; int rc = 0; if (ops->done) @@ -682,9 +752,9 @@ static int genl_family_rcv_msg(const struct genl_family *family, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { - const struct genl_ops *ops; struct net *net = sock_net(skb->sk); struct genlmsghdr *hdr = nlmsg_data(nlh); + struct genl_ops op; int hdrlen; /* this family doesn't exist in this netns */ @@ -695,24 +765,23 @@ static int genl_family_rcv_msg(const struct genl_family *family, if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) return -EINVAL; - ops = genl_get_cmd(hdr->cmd, family); - if (ops == NULL) + if (genl_get_cmd(hdr->cmd, family, &op)) return -EOPNOTSUPP; - if ((ops->flags & GENL_ADMIN_PERM) && + if ((op.flags & GENL_ADMIN_PERM) && !netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; - if ((ops->flags & GENL_UNS_ADMIN_PERM) && + if ((op.flags & GENL_UNS_ADMIN_PERM) && !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) return genl_family_rcv_msg_dumpit(family, skb, nlh, extack, - ops, hdrlen, net); + &op, hdrlen, net); else return genl_family_rcv_msg_doit(family, skb, nlh, extack, - ops, hdrlen, net); + &op, hdrlen, net); } static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, @@ -765,7 +834,7 @@ 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 (family->n_ops) { + if (genl_get_cmd_cnt(family)) { struct nlattr *nla_ops; int i; @@ -773,23 +842,25 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, if (nla_ops == NULL) goto nla_put_failure; - for (i = 0; i < family->n_ops; i++) { + for (i = 0; i < genl_get_cmd_cnt(family); i++) { struct nlattr *nest; - const struct genl_ops *ops = &family->ops[i]; - u32 op_flags = ops->flags; + struct genl_ops op; + u32 op_flags; - if (ops->dumpit) + genl_get_cmd_by_index(i, family, &op); + op_flags = op.flags; + if (op.dumpit) op_flags |= GENL_CMD_CAP_DUMP; - if (ops->doit) + if (op.doit) op_flags |= GENL_CMD_CAP_DO; - if (family->policy) + if (op.policy) op_flags |= GENL_CMD_CAP_HASPOL; nest = nla_nest_start_noflag(skb, i + 1); if (nest == NULL) goto nla_put_failure; - if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) || + if (nla_put_u32(skb, CTRL_ATTR_OP_ID, op.cmd) || nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags)) goto nla_put_failure; @@ -945,7 +1016,7 @@ ctrl_build_mcgrp_msg(const struct genl_family *family, return skb; } -static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = { +static const struct nla_policy ctrl_policy_family[] = { [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, .len = GENL_NAMSIZ - 1 }, @@ -1039,83 +1110,218 @@ static int genl_ctrl_event(int event, const struct genl_family *family, return 0; } -static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) -{ +struct ctrl_dump_policy_ctx { + struct netlink_policy_dump_state *state; const struct genl_family *rt; - unsigned int fam_id = cb->args[0]; - int err; + unsigned int opidx; + u32 op; + u16 fam_id; + u8 policies:1, + single_op:1; +}; - if (!fam_id) { - struct nlattr *tb[CTRL_ATTR_MAX + 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 }, +}; - err = genlmsg_parse(cb->nlh, &genl_ctrl, tb, - genl_ctrl.maxattr, - genl_ctrl.policy, cb->extack); - if (err) - return err; +static int ctrl_dumppolicy_start(struct netlink_callback *cb) +{ + const struct genl_dumpit_info *info = genl_dumpit_info(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; - if (!tb[CTRL_ATTR_FAMILY_ID] && !tb[CTRL_ATTR_FAMILY_NAME]) - return -EINVAL; + BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx)); - if (tb[CTRL_ATTR_FAMILY_ID]) { - fam_id = nla_get_u16(tb[CTRL_ATTR_FAMILY_ID]); - } else { - rt = genl_family_find_byname( - nla_data(tb[CTRL_ATTR_FAMILY_NAME])); - if (!rt) - return -ENOENT; - fam_id = rt->id; - } + if (!tb[CTRL_ATTR_FAMILY_ID] && !tb[CTRL_ATTR_FAMILY_NAME]) + return -EINVAL; + + if (tb[CTRL_ATTR_FAMILY_ID]) { + ctx->fam_id = nla_get_u16(tb[CTRL_ATTR_FAMILY_ID]); + } else { + rt = genl_family_find_byname( + nla_data(tb[CTRL_ATTR_FAMILY_NAME])); + if (!rt) + return -ENOENT; + ctx->fam_id = rt->id; } - rt = genl_family_find_byid(fam_id); + rt = genl_family_find_byid(ctx->fam_id); if (!rt) return -ENOENT; - if (!rt->policy) + 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); + + if (op.policy) { + err = netlink_policy_dump_add_policy(&ctx->state, + op.policy, + op.maxattr); + if (err) + return err; + } + } + + if (!ctx->state) return -ENODATA; + return 0; +} - err = netlink_policy_dump_start(rt->policy, rt->maxattr, &cb->args[1]); - if (err) - return err; +static void *ctrl_dumppolicy_prep(struct sk_buff *skb, + struct netlink_callback *cb) +{ + struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; + void *hdr; + + hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, &genl_ctrl, + NLM_F_MULTI, CTRL_CMD_GETPOLICY); + if (!hdr) + return NULL; + + if (nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, ctx->fam_id)) + return NULL; + + return hdr; +} + +static int ctrl_dumppolicy_put_op(struct sk_buff *skb, + struct netlink_callback *cb, + struct genl_ops *op) +{ + struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; + struct nlattr *nest_pol, *nest_op; + void *hdr; + int idx; + + /* skip if we have nothing to show */ + if (!op->policy) + return 0; + if (!op->doit && + (!op->dumpit || op->validate & GENL_DONT_VALIDATE_DUMP)) + return 0; + + hdr = ctrl_dumppolicy_prep(skb, cb); + if (!hdr) + return -ENOBUFS; + + nest_pol = nla_nest_start(skb, CTRL_ATTR_OP_POLICY); + if (!nest_pol) + goto err; + + nest_op = nla_nest_start(skb, op->cmd); + if (!nest_op) + goto err; + + /* for now both do/dump are always the same */ + idx = netlink_policy_dump_get_policy_idx(ctx->state, + op->policy, + op->maxattr); + + if (op->doit && nla_put_u32(skb, CTRL_ATTR_POLICY_DO, idx)) + goto err; + + if (op->dumpit && !(op->validate & GENL_DONT_VALIDATE_DUMP) && + nla_put_u32(skb, CTRL_ATTR_POLICY_DUMP, idx)) + goto err; + + nla_nest_end(skb, nest_op); + nla_nest_end(skb, nest_pol); + genlmsg_end(skb, hdr); - while (netlink_policy_dump_loop(cb->args[1])) { - void *hdr; + return 0; +err: + genlmsg_cancel(skb, hdr); + return -ENOBUFS; +} + +static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; + void *hdr; + + if (!ctx->policies) { + while (ctx->opidx < genl_get_cmd_cnt(ctx->rt)) { + struct genl_ops 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; + + ctx->opidx++; + } + + /* completed with the per-op policy index list */ + ctx->policies = true; + } + + while (netlink_policy_dump_loop(ctx->state)) { struct nlattr *nest; - hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, &genl_ctrl, - NLM_F_MULTI, CTRL_CMD_GETPOLICY); + hdr = ctrl_dumppolicy_prep(skb, cb); if (!hdr) goto nla_put_failure; - if (nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, rt->id)) - goto nla_put_failure; - nest = nla_nest_start(skb, CTRL_ATTR_POLICY); if (!nest) goto nla_put_failure; - if (netlink_policy_dump_write(skb, cb->args[1])) + if (netlink_policy_dump_write(skb, ctx->state)) goto nla_put_failure; nla_nest_end(skb, nest); genlmsg_end(skb, hdr); - continue; - -nla_put_failure: - genlmsg_cancel(skb, hdr); - break; } - cb->args[0] = fam_id; + return skb->len; + +nla_put_failure: + genlmsg_cancel(skb, hdr); return skb->len; } static int ctrl_dumppolicy_done(struct netlink_callback *cb) { - netlink_policy_dump_free(cb->args[1]); + struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx; + + netlink_policy_dump_free(ctx->state); return 0; } @@ -1123,11 +1329,16 @@ static const struct genl_ops genl_ctrl_ops[] = { { .cmd = CTRL_CMD_GETFAMILY, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, + .policy = ctrl_policy_family, + .maxattr = ARRAY_SIZE(ctrl_policy_family) - 1, .doit = ctrl_getfamily, .dumpit = ctrl_dumpfamily, }, { .cmd = CTRL_CMD_GETPOLICY, + .policy = ctrl_policy_policy, + .maxattr = ARRAY_SIZE(ctrl_policy_policy) - 1, + .start = ctrl_dumppolicy_start, .dumpit = ctrl_dumppolicy, .done = ctrl_dumppolicy_done, }, @@ -1146,8 +1357,6 @@ static struct genl_family genl_ctrl __ro_after_init = { .id = GENL_ID_CTRL, .name = "nlctrl", .version = 0x2, - .maxattr = CTRL_ATTR_MAX, - .policy = ctrl_policy, .netnsok = true, }; diff --git a/net/netlink/policy.c b/net/netlink/policy.c index 0176b59ce530..8d7c900e27f4 100644 --- a/net/netlink/policy.c +++ b/net/netlink/policy.c @@ -14,7 +14,7 @@ #define INITIAL_POLICIES_ALLOC 10 -struct nl_policy_dump { +struct netlink_policy_dump_state { unsigned int policy_idx; unsigned int attr_idx; unsigned int n_alloc; @@ -24,18 +24,19 @@ struct nl_policy_dump { } policies[]; }; -static int add_policy(struct nl_policy_dump **statep, +static int add_policy(struct netlink_policy_dump_state **statep, const struct nla_policy *policy, unsigned int maxtype) { - struct nl_policy_dump *state = *statep; + struct netlink_policy_dump_state *state = *statep; unsigned int n_alloc, i; if (!policy || !maxtype) return 0; for (i = 0; i < state->n_alloc; i++) { - if (state->policies[i].policy == policy) + if (state->policies[i].policy == policy && + state->policies[i].maxtype == maxtype) return 0; if (!state->policies[i].policy) { @@ -62,42 +63,85 @@ static int add_policy(struct nl_policy_dump **statep, return 0; } -static unsigned int get_policy_idx(struct nl_policy_dump *state, - const struct nla_policy *policy) +/** + * netlink_policy_dump_get_policy_idx - retrieve policy index + * @state: the policy dump state + * @policy: the policy to find + * @maxtype: the policy's maxattr + * + * Returns: the index of the given policy in the dump state + * + * Call this to find a policy index when you've added multiple and e.g. + * need to tell userspace which command has which policy (by index). + * + * Note: this will WARN and return 0 if the policy isn't found, which + * means it wasn't added in the first place, which would be an + * internal consistency bug. + */ +int netlink_policy_dump_get_policy_idx(struct netlink_policy_dump_state *state, + const struct nla_policy *policy, + unsigned int maxtype) { unsigned int i; + if (WARN_ON(!policy || !maxtype)) + return 0; + for (i = 0; i < state->n_alloc; i++) { - if (state->policies[i].policy == policy) + if (state->policies[i].policy == policy && + state->policies[i].maxtype == maxtype) return i; } - WARN_ON_ONCE(1); - return -1; + WARN_ON(1); + return 0; +} + +static struct netlink_policy_dump_state *alloc_state(void) +{ + struct netlink_policy_dump_state *state; + + state = kzalloc(struct_size(state, policies, INITIAL_POLICIES_ALLOC), + GFP_KERNEL); + if (!state) + return ERR_PTR(-ENOMEM); + state->n_alloc = INITIAL_POLICIES_ALLOC; + + return state; } -int netlink_policy_dump_start(const struct nla_policy *policy, - unsigned int maxtype, - unsigned long *_state) +/** + * netlink_policy_dump_add_policy - add a policy to the dump + * @pstate: state to add to, may be reallocated, must be %NULL the first time + * @policy: the new policy to add to the dump + * @maxtype: the new policy's max attr type + * + * Returns: 0 on success, a negative error code otherwise. + * + * Call this to allocate a policy dump state, and to add policies to it. This + * should be called from the dump start() callback. + * + * Note: on failures, any previously allocated state is freed. + */ +int netlink_policy_dump_add_policy(struct netlink_policy_dump_state **pstate, + const struct nla_policy *policy, + unsigned int maxtype) { - struct nl_policy_dump *state; + struct netlink_policy_dump_state *state = *pstate; unsigned int policy_idx; int err; - if (*_state) - return 0; + if (!state) { + state = alloc_state(); + if (IS_ERR(state)) + return PTR_ERR(state); + } /* * walk the policies and nested ones first, and build * a linear list of them. */ - state = kzalloc(struct_size(state, policies, INITIAL_POLICIES_ALLOC), - GFP_KERNEL); - if (!state) - return -ENOMEM; - state->n_alloc = INITIAL_POLICIES_ALLOC; - err = add_policy(&state, policy, maxtype); if (err) return err; @@ -128,62 +172,103 @@ int netlink_policy_dump_start(const struct nla_policy *policy, } } - *_state = (unsigned long)state; - + *pstate = state; return 0; } -static bool netlink_policy_dump_finished(struct nl_policy_dump *state) +static bool +netlink_policy_dump_finished(struct netlink_policy_dump_state *state) { return state->policy_idx >= state->n_alloc || !state->policies[state->policy_idx].policy; } -bool netlink_policy_dump_loop(unsigned long _state) +/** + * netlink_policy_dump_loop - dumping loop indicator + * @state: the policy dump state + * + * Returns: %true if the dump continues, %false otherwise + * + * Note: this frees the dump state when finishing + */ +bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state) { - struct nl_policy_dump *state = (void *)_state; - return !netlink_policy_dump_finished(state); } -int netlink_policy_dump_write(struct sk_buff *skb, unsigned long _state) +int netlink_policy_dump_attr_size_estimate(const struct nla_policy *pt) { - struct nl_policy_dump *state = (void *)_state; - const struct nla_policy *pt; - struct nlattr *policy, *attr; - enum netlink_attribute_type type; - bool again; + /* nested + type */ + int common = 2 * nla_attr_size(sizeof(u32)); -send_attribute: - again = false; + switch (pt->type) { + case NLA_UNSPEC: + case NLA_REJECT: + /* these actually don't need any space */ + return 0; + case NLA_NESTED: + case NLA_NESTED_ARRAY: + /* common, policy idx, policy maxattr */ + return common + 2 * nla_attr_size(sizeof(u32)); + case NLA_U8: + case NLA_U16: + case NLA_U32: + case NLA_U64: + case NLA_MSECS: + case NLA_S8: + case NLA_S16: + case NLA_S32: + case NLA_S64: + /* maximum is common, u64 min/max with padding */ + return common + + 2 * (nla_attr_size(0) + nla_attr_size(sizeof(u64))); + case NLA_BITFIELD32: + return common + nla_attr_size(sizeof(u32)); + case NLA_STRING: + case NLA_NUL_STRING: + case NLA_BINARY: + /* maximum is common, u32 min-length/max-length */ + return common + 2 * nla_attr_size(sizeof(u32)); + case NLA_FLAG: + return common; + } - pt = &state->policies[state->policy_idx].policy[state->attr_idx]; + /* this should then cause a warning later */ + return 0; +} - policy = nla_nest_start(skb, state->policy_idx); - if (!policy) - return -ENOBUFS; +static int +__netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state, + struct sk_buff *skb, + const struct nla_policy *pt, + int nestattr) +{ + int estimate = netlink_policy_dump_attr_size_estimate(pt); + enum netlink_attribute_type type; + struct nlattr *attr; - attr = nla_nest_start(skb, state->attr_idx); + attr = nla_nest_start(skb, nestattr); if (!attr) - goto nla_put_failure; + return -ENOBUFS; switch (pt->type) { default: case NLA_UNSPEC: case NLA_REJECT: /* skip - use NLA_MIN_LEN to advertise such */ - nla_nest_cancel(skb, policy); - again = true; - goto next; + nla_nest_cancel(skb, attr); + return -ENODATA; case NLA_NESTED: type = NL_ATTR_TYPE_NESTED; fallthrough; case NLA_NESTED_ARRAY: if (pt->type == NLA_NESTED_ARRAY) type = NL_ATTR_TYPE_NESTED_ARRAY; - if (pt->nested_policy && pt->len && + if (state && pt->nested_policy && pt->len && (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_IDX, - get_policy_idx(state, pt->nested_policy)) || + netlink_policy_dump_get_policy_idx(state, + pt->nested_policy, + pt->len)) || nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE, pt->len))) goto nla_put_failure; @@ -204,6 +289,14 @@ send_attribute: else type = NL_ATTR_TYPE_U64; + if (pt->validation_type == NLA_VALIDATE_MASK) { + if (nla_put_u64_64bit(skb, NL_POLICY_TYPE_ATTR_MASK, + pt->mask, + NL_POLICY_TYPE_ATTR_PAD)) + goto nla_put_failure; + break; + } + nla_get_range_unsigned(pt, &range); if (nla_put_u64_64bit(skb, NL_POLICY_TYPE_ATTR_MIN_VALUE_U, @@ -243,12 +336,6 @@ send_attribute: pt->bitfield32_valid)) goto nla_put_failure; break; - case NLA_EXACT_LEN: - type = NL_ATTR_TYPE_BINARY; - if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len) || - nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, pt->len)) - goto nla_put_failure; - break; case NLA_STRING: case NLA_NUL_STRING: case NLA_BINARY: @@ -258,14 +345,27 @@ send_attribute: type = NL_ATTR_TYPE_NUL_STRING; else type = NL_ATTR_TYPE_BINARY; - if (pt->len && nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, - pt->len)) - goto nla_put_failure; - break; - case NLA_MIN_LEN: - type = NL_ATTR_TYPE_BINARY; - if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, pt->len)) + + if (pt->validation_type == NLA_VALIDATE_RANGE || + pt->validation_type == NLA_VALIDATE_RANGE_WARN_TOO_LONG) { + struct netlink_range_validation range; + + nla_get_range_unsigned(pt, &range); + + if (range.min && + nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MIN_LENGTH, + range.min)) + goto nla_put_failure; + + if (range.max < U16_MAX && + nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, + range.max)) + goto nla_put_failure; + } else if (pt->len && + nla_put_u32(skb, NL_POLICY_TYPE_ATTR_MAX_LENGTH, + pt->len)) { goto nla_put_failure; + } break; case NLA_FLAG: type = NL_ATTR_TYPE_FLAG; @@ -275,8 +375,66 @@ send_attribute: if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_TYPE, type)) goto nla_put_failure; - /* finish and move state to next attribute */ nla_nest_end(skb, attr); + WARN_ON(attr->nla_len > estimate); + + return 0; +nla_put_failure: + nla_nest_cancel(skb, attr); + return -ENOBUFS; +} + +/** + * netlink_policy_dump_write_attr - write a given attribute policy + * @skb: the message skb to write to + * @pt: the attribute's policy + * @nestattr: the nested attribute ID to use + * + * Returns: 0 on success, an error code otherwise; -%ENODATA is + * special, indicating that there's no policy data and + * the attribute is generally rejected. + */ +int netlink_policy_dump_write_attr(struct sk_buff *skb, + const struct nla_policy *pt, + int nestattr) +{ + return __netlink_policy_dump_write_attr(NULL, skb, pt, nestattr); +} + +/** + * netlink_policy_dump_write - write current policy dump attributes + * @skb: the message skb to write to + * @state: the policy dump state + * + * Returns: 0 on success, an error code otherwise + */ +int netlink_policy_dump_write(struct sk_buff *skb, + struct netlink_policy_dump_state *state) +{ + const struct nla_policy *pt; + struct nlattr *policy; + bool again; + int err; + +send_attribute: + again = false; + + pt = &state->policies[state->policy_idx].policy[state->attr_idx]; + + policy = nla_nest_start(skb, state->policy_idx); + if (!policy) + return -ENOBUFS; + + err = __netlink_policy_dump_write_attr(state, skb, pt, state->attr_idx); + if (err == -ENODATA) { + nla_nest_cancel(skb, policy); + again = true; + goto next; + } else if (err) { + goto nla_put_failure; + } + + /* finish and move state to next attribute */ nla_nest_end(skb, policy); next: @@ -299,9 +457,13 @@ nla_put_failure: return -ENOBUFS; } -void netlink_policy_dump_free(unsigned long _state) +/** + * netlink_policy_dump_free - free policy dump state + * @state: the policy dump state to free + * + * Call this from the done() method to ensure dump state is freed. + */ +void netlink_policy_dump_free(struct netlink_policy_dump_state *state) { - struct nl_policy_dump *state = (void *)_state; - kfree(state); } |