From e1ce69df7e6e8cbdca78ae831ecf435b12b4c168 Mon Sep 17 00:00:00 2001 From: Huw Davies Date: Mon, 27 Jun 2016 15:02:48 -0400 Subject: [PATCH] netlabel: Add support for enumerating the CALIPSO DOI list. Enumerate the DOI list through the NLBL_CALIPSO_C_LISTALL command. It takes no attributes. Signed-off-by: Huw Davies Signed-off-by: Paul Moore --- include/net/netlabel.h | 4 ++ net/ipv6/calipso.c | 41 ++++++++++++ net/netlabel/netlabel_calipso.c | 106 ++++++++++++++++++++++++++++++++ net/netlabel/netlabel_calipso.h | 14 +++++ 4 files changed, 165 insertions(+) diff --git a/include/net/netlabel.h b/include/net/netlabel.h index 0f05b83851e2..2653d3a8cde8 100644 --- a/include/net/netlabel.h +++ b/include/net/netlabel.h @@ -225,6 +225,7 @@ struct netlbl_lsm_secattr { * @doi_free: free a CALIPSO DOI * @doi_getdef: returns a reference to a DOI * @doi_putdef: releases a reference of a DOI + * @doi_walk: enumerate the DOI list * * Description: * This structure is filled out by the CALIPSO engine and passed @@ -238,6 +239,9 @@ struct netlbl_calipso_ops { void (*doi_free)(struct calipso_doi *doi_def); struct calipso_doi *(*doi_getdef)(u32 doi); void (*doi_putdef)(struct calipso_doi *doi_def); + int (*doi_walk)(u32 *skip_cnt, + int (*callback)(struct calipso_doi *doi_def, void *arg), + void *cb_arg); }; /* diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c index 128cc6945e34..fa17c7a7f4be 100644 --- a/net/ipv6/calipso.c +++ b/net/ipv6/calipso.c @@ -210,11 +210,52 @@ static void calipso_doi_putdef(struct calipso_doi *doi_def) call_rcu(&doi_def->rcu, calipso_doi_free_rcu); } +/** + * calipso_doi_walk - Iterate through the DOI definitions + * @skip_cnt: skip past this number of DOI definitions, updated + * @callback: callback for each DOI definition + * @cb_arg: argument for the callback function + * + * Description: + * Iterate over the DOI definition list, skipping the first @skip_cnt entries. + * For each entry call @callback, if @callback returns a negative value stop + * 'walking' through the list and return. Updates the value in @skip_cnt upon + * return. Returns zero on success, negative values on failure. + * + */ +static int calipso_doi_walk(u32 *skip_cnt, + int (*callback)(struct calipso_doi *doi_def, + void *arg), + void *cb_arg) +{ + int ret_val = -ENOENT; + u32 doi_cnt = 0; + struct calipso_doi *iter_doi; + + rcu_read_lock(); + list_for_each_entry_rcu(iter_doi, &calipso_doi_list, list) + if (atomic_read(&iter_doi->refcount) > 0) { + if (doi_cnt++ < *skip_cnt) + continue; + ret_val = callback(iter_doi, cb_arg); + if (ret_val < 0) { + doi_cnt--; + goto doi_walk_return; + } + } + +doi_walk_return: + rcu_read_unlock(); + *skip_cnt = doi_cnt; + return ret_val; +} + static const struct netlbl_calipso_ops ops = { .doi_add = calipso_doi_add, .doi_free = calipso_doi_free, .doi_getdef = calipso_doi_getdef, .doi_putdef = calipso_doi_putdef, + .doi_walk = calipso_doi_walk, }; /** diff --git a/net/netlabel/netlabel_calipso.c b/net/netlabel/netlabel_calipso.c index 6161170dc5f4..214114575812 100644 --- a/net/netlabel/netlabel_calipso.c +++ b/net/netlabel/netlabel_calipso.c @@ -46,6 +46,13 @@ #include "netlabel_mgmt.h" #include "netlabel_domainhash.h" +/* Argument struct for calipso_doi_walk() */ +struct netlbl_calipso_doiwalk_arg { + struct netlink_callback *nl_cb; + struct sk_buff *skb; + u32 seq; +}; + /* NetLabel Generic NETLINK CALIPSO family */ static struct genl_family netlbl_calipso_gnl_family = { .id = GENL_ID_GENERATE, @@ -183,6 +190,73 @@ list_failure: return ret_val; } +/** + * netlbl_calipso_listall_cb - calipso_doi_walk() callback for LISTALL + * @doi_def: the CALIPSO DOI definition + * @arg: the netlbl_calipso_doiwalk_arg structure + * + * Description: + * This function is designed to be used as a callback to the + * calipso_doi_walk() function for use in generating a response for a LISTALL + * message. Returns the size of the message on success, negative values on + * failure. + * + */ +static int netlbl_calipso_listall_cb(struct calipso_doi *doi_def, void *arg) +{ + int ret_val = -ENOMEM; + struct netlbl_calipso_doiwalk_arg *cb_arg = arg; + void *data; + + data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid, + cb_arg->seq, &netlbl_calipso_gnl_family, + NLM_F_MULTI, NLBL_CALIPSO_C_LISTALL); + if (!data) + goto listall_cb_failure; + + ret_val = nla_put_u32(cb_arg->skb, NLBL_CALIPSO_A_DOI, doi_def->doi); + if (ret_val != 0) + goto listall_cb_failure; + ret_val = nla_put_u32(cb_arg->skb, + NLBL_CALIPSO_A_MTYPE, + doi_def->type); + if (ret_val != 0) + goto listall_cb_failure; + + genlmsg_end(cb_arg->skb, data); + return 0; + +listall_cb_failure: + genlmsg_cancel(cb_arg->skb, data); + return ret_val; +} + +/** + * netlbl_calipso_listall - Handle a LISTALL message + * @skb: the NETLINK buffer + * @cb: the NETLINK callback + * + * Description: + * Process a user generated LISTALL message and respond accordingly. Returns + * zero on success and negative values on error. + * + */ +static int netlbl_calipso_listall(struct sk_buff *skb, + struct netlink_callback *cb) +{ + struct netlbl_calipso_doiwalk_arg cb_arg; + u32 doi_skip = cb->args[0]; + + cb_arg.nl_cb = cb; + cb_arg.skb = skb; + cb_arg.seq = cb->nlh->nlmsg_seq; + + calipso_doi_walk(&doi_skip, netlbl_calipso_listall_cb, &cb_arg); + + cb->args[0] = doi_skip; + return skb->len; +} + /* NetLabel Generic NETLINK Command Definitions */ @@ -201,6 +275,13 @@ static const struct genl_ops netlbl_calipso_ops[] = { .doit = netlbl_calipso_list, .dumpit = NULL, }, + { + .cmd = NLBL_CALIPSO_C_LISTALL, + .flags = 0, + .policy = calipso_genl_policy, + .doit = NULL, + .dumpit = netlbl_calipso_listall, + }, }; /* NetLabel Generic NETLINK Protocol Functions @@ -316,3 +397,28 @@ void calipso_doi_putdef(struct calipso_doi *doi_def) if (ops) ops->doi_putdef(doi_def); } + +/** + * calipso_doi_walk - Iterate through the DOI definitions + * @skip_cnt: skip past this number of DOI definitions, updated + * @callback: callback for each DOI definition + * @cb_arg: argument for the callback function + * + * Description: + * Iterate over the DOI definition list, skipping the first @skip_cnt entries. + * For each entry call @callback, if @callback returns a negative value stop + * 'walking' through the list and return. Updates the value in @skip_cnt upon + * return. Returns zero on success, negative values on failure. + * + */ +int calipso_doi_walk(u32 *skip_cnt, + int (*callback)(struct calipso_doi *doi_def, void *arg), + void *cb_arg) +{ + int ret_val = -ENOMSG; + const struct netlbl_calipso_ops *ops = netlbl_calipso_ops_get(); + + if (ops) + ret_val = ops->doi_walk(skip_cnt, callback, cb_arg); + return ret_val; +} diff --git a/net/netlabel/netlabel_calipso.h b/net/netlabel/netlabel_calipso.h index 6da737a9f37a..1f24174466e4 100644 --- a/net/netlabel/netlabel_calipso.h +++ b/net/netlabel/netlabel_calipso.h @@ -63,6 +63,17 @@ * * If using CALIPSO_MAP_PASS no additional attributes are required. * + * o LISTALL: + * This message is sent by an application to list the valid DOIs on the + * system. When sent by an application there is no payload and the + * NLM_F_DUMP flag should be set. The kernel should respond with a series of + * the following messages. + * + * Required attributes: + * + * NLBL_CALIPSO_A_DOI + * NLBL_CALIPSO_A_MTYPE + * */ /* NetLabel CALIPSO commands */ @@ -105,5 +116,8 @@ int calipso_doi_add(struct calipso_doi *doi_def, void calipso_doi_free(struct calipso_doi *doi_def); struct calipso_doi *calipso_doi_getdef(u32 doi); void calipso_doi_putdef(struct calipso_doi *doi_def); +int calipso_doi_walk(u32 *skip_cnt, + int (*callback)(struct calipso_doi *doi_def, void *arg), + void *cb_arg); #endif -- 2.39.5