From 3f935c75eb52dd968351dba824adf466fb9c9429 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Thu, 9 Jul 2020 15:12:39 +0200 Subject: [PATCH] inet_diag: support for wider protocol numbers After commit bf9765145b85 ("sock: Make sk_protocol a 16-bit value") the current size of 'sdiag_protocol' is not sufficient to represent the possible protocol values. This change introduces a new inet diag request attribute to let user space specify the relevant protocol number using u32 values. The attribute is parsed by inet diag core on get/dump command and the extended protocol value, if available, is preferred to 'sdiag_protocol' to lookup the diag handler. The parse attributed are exposed to all the diag handlers via the cb->data. Note that inet_diag_dump_one_icsk() is left unmodified, as it will not be used by protocol using the extended attribute. Suggested-by: David S. Miller Co-developed-by: Christoph Paasch Signed-off-by: Christoph Paasch Acked-by: Mat Martineau Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- include/uapi/linux/inet_diag.h | 1 + net/core/sock.c | 1 + net/ipv4/inet_diag.c | 65 +++++++++++++++++++++++++++++++----------- 3 files changed, 50 insertions(+), 17 deletions(-) diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h index e6f183e..5ba122c 100644 --- a/include/uapi/linux/inet_diag.h +++ b/include/uapi/linux/inet_diag.h @@ -65,6 +65,7 @@ enum { INET_DIAG_REQ_NONE, INET_DIAG_REQ_BYTECODE, INET_DIAG_REQ_SK_BPF_STORAGES, + INET_DIAG_REQ_PROTOCOL, __INET_DIAG_REQ_MAX, }; diff --git a/net/core/sock.c b/net/core/sock.c index f5b5fdd..de26fe4 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3566,6 +3566,7 @@ int sock_load_diag_module(int family, int protocol) #ifdef CONFIG_INET if (family == AF_INET && protocol != IPPROTO_RAW && + protocol < MAX_INET_PROTOS && !rcu_access_pointer(inet_protos[protocol])) return -ENOENT; #endif diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 125f4f8..4a98dd7 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -52,6 +52,11 @@ static DEFINE_MUTEX(inet_diag_table_mutex); static const struct inet_diag_handler *inet_diag_lock_handler(int proto) { + if (proto < 0 || proto >= IPPROTO_MAX) { + mutex_lock(&inet_diag_table_mutex); + return ERR_PTR(-ENOENT); + } + if (!inet_diag_table[proto]) sock_load_diag_module(AF_INET, proto); @@ -181,6 +186,28 @@ errout: } EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill); +static void inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen, + struct nlattr **req_nlas) +{ + struct nlattr *nla; + int remaining; + + nlmsg_for_each_attr(nla, nlh, hdrlen, remaining) { + int type = nla_type(nla); + + if (type < __INET_DIAG_REQ_MAX) + req_nlas[type] = nla; + } +} + +static int inet_diag_get_protocol(const struct inet_diag_req_v2 *req, + const struct inet_diag_dump_data *data) +{ + if (data->req_nlas[INET_DIAG_REQ_PROTOCOL]) + return nla_get_u32(data->req_nlas[INET_DIAG_REQ_PROTOCOL]); + return req->sdiag_protocol; +} + #define MAX_DUMP_ALLOC_SIZE (KMALLOC_MAX_SIZE - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, @@ -198,7 +225,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk, void *info = NULL; cb_data = cb->data; - handler = inet_diag_table[req->sdiag_protocol]; + handler = inet_diag_table[inet_diag_get_protocol(req, cb_data)]; BUG_ON(!handler); nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, @@ -539,20 +566,25 @@ EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk); static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb, const struct nlmsghdr *nlh, + int hdrlen, const struct inet_diag_req_v2 *req) { const struct inet_diag_handler *handler; - int err; + struct inet_diag_dump_data dump_data; + int err, protocol; - handler = inet_diag_lock_handler(req->sdiag_protocol); + memset(&dump_data, 0, sizeof(dump_data)); + inet_diag_parse_attrs(nlh, hdrlen, dump_data.req_nlas); + protocol = inet_diag_get_protocol(req, &dump_data); + + handler = inet_diag_lock_handler(protocol); if (IS_ERR(handler)) { err = PTR_ERR(handler); } else if (cmd == SOCK_DIAG_BY_FAMILY) { - struct inet_diag_dump_data empty_dump_data = {}; struct netlink_callback cb = { .nlh = nlh, .skb = in_skb, - .data = &empty_dump_data, + .data = &dump_data, }; err = handler->dump_one(&cb, req); } else if (cmd == SOCK_DESTROY && handler->destroy) { @@ -1103,13 +1135,16 @@ EXPORT_SYMBOL_GPL(inet_diag_dump_icsk); static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, const struct inet_diag_req_v2 *r) { + struct inet_diag_dump_data *cb_data = cb->data; const struct inet_diag_handler *handler; u32 prev_min_dump_alloc; - int err = 0; + int protocol, err = 0; + + protocol = inet_diag_get_protocol(r, cb_data); again: prev_min_dump_alloc = cb->min_dump_alloc; - handler = inet_diag_lock_handler(r->sdiag_protocol); + handler = inet_diag_lock_handler(protocol); if (!IS_ERR(handler)) handler->dump(skb, cb, r); else @@ -1139,19 +1174,13 @@ static int __inet_diag_dump_start(struct netlink_callback *cb, int hdrlen) struct inet_diag_dump_data *cb_data; struct sk_buff *skb = cb->skb; struct nlattr *nla; - int rem, err; + int err; cb_data = kzalloc(sizeof(*cb_data), GFP_KERNEL); if (!cb_data) return -ENOMEM; - nla_for_each_attr(nla, nlmsg_attrdata(nlh, hdrlen), - nlmsg_attrlen(nlh, hdrlen), rem) { - int type = nla_type(nla); - - if (type < __INET_DIAG_REQ_MAX) - cb_data->req_nlas[type] = nla; - } + inet_diag_parse_attrs(nlh, hdrlen, cb_data->req_nlas); nla = cb_data->inet_diag_nla_bc; if (nla) { @@ -1237,7 +1266,8 @@ static int inet_diag_get_exact_compat(struct sk_buff *in_skb, req.idiag_states = rc->idiag_states; req.id = rc->id; - return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh, &req); + return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh, + sizeof(struct inet_diag_req), &req); } static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh) @@ -1279,7 +1309,8 @@ static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h) return netlink_dump_start(net->diag_nlsk, skb, h, &c); } - return inet_diag_cmd_exact(h->nlmsg_type, skb, h, nlmsg_data(h)); + return inet_diag_cmd_exact(h->nlmsg_type, skb, h, hdrlen, + nlmsg_data(h)); } static -- 2.7.4