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libnl/lib/route/rule.c

758 lines
18 KiB
C

/*
* lib/route/rule.c Routing Rules
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2010 Thomas Graf <tgraf@suug.ch>
*/
/**
* @ingroup rtnl
* @defgroup rule Routing Rules
* @brief
* @{
*/
#include <netlink-private/netlink.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink/route/rtnl.h>
#include <netlink/route/rule.h>
#include <inttypes.h>
/** @cond SKIP */
#define RULE_ATTR_FAMILY 0x0001
#define RULE_ATTR_TABLE 0x0002
#define RULE_ATTR_ACTION 0x0004
#define RULE_ATTR_FLAGS 0x0008
#define RULE_ATTR_IIFNAME 0x0010
#define RULE_ATTR_OIFNAME 0x0020
#define RULE_ATTR_PRIO 0x0040
#define RULE_ATTR_MARK 0x0080
#define RULE_ATTR_MASK 0x0100
#define RULE_ATTR_GOTO 0x0200
#define RULE_ATTR_SRC 0x0400
#define RULE_ATTR_DST 0x0800
#define RULE_ATTR_DSFIELD 0x1000
#define RULE_ATTR_FLOW 0x2000
static struct nl_cache_ops rtnl_rule_ops;
static struct nl_object_ops rule_obj_ops;
/** @endcond */
static void rule_free_data(struct nl_object *c)
{
struct rtnl_rule *rule = nl_object_priv(c);
if (!rule)
return;
nl_addr_put(rule->r_src);
nl_addr_put(rule->r_dst);
}
static int rule_clone(struct nl_object *_dst, struct nl_object *_src)
{
struct rtnl_rule *dst = nl_object_priv(_dst);
struct rtnl_rule *src = nl_object_priv(_src);
if (src->r_src)
if (!(dst->r_src = nl_addr_clone(src->r_src)))
return -NLE_NOMEM;
if (src->r_dst)
if (!(dst->r_dst = nl_addr_clone(src->r_dst)))
return -NLE_NOMEM;
return 0;
}
static struct nla_policy rule_policy[FRA_MAX+1] = {
[FRA_TABLE] = { .type = NLA_U32 },
[FRA_IIFNAME] = { .type = NLA_STRING, .maxlen = IFNAMSIZ },
[FRA_OIFNAME] = { .type = NLA_STRING, .maxlen = IFNAMSIZ },
[FRA_PRIORITY] = { .type = NLA_U32 },
[FRA_FWMARK] = { .type = NLA_U32 },
[FRA_FWMASK] = { .type = NLA_U32 },
[FRA_GOTO] = { .type = NLA_U32 },
[FRA_FLOW] = { .type = NLA_U32 },
};
static int rule_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
struct nlmsghdr *n, struct nl_parser_param *pp)
{
struct rtnl_rule *rule;
struct fib_rule_hdr *frh;
struct nlattr *tb[FRA_MAX+1];
int err = 1, family;
rule = rtnl_rule_alloc();
if (!rule) {
err = -NLE_NOMEM;
goto errout;
}
rule->ce_msgtype = n->nlmsg_type;
frh = nlmsg_data(n);
err = nlmsg_parse(n, sizeof(*frh), tb, FRA_MAX, rule_policy);
if (err < 0)
goto errout;
rule->r_family = family = frh->family;
rule->r_table = frh->table;
rule->r_action = frh->action;
rule->r_flags = frh->flags;
rule->ce_mask = (RULE_ATTR_FAMILY | RULE_ATTR_TABLE | RULE_ATTR_ACTION |
RULE_ATTR_FLAGS);
/* ipv4 only */
if (frh->tos) {
rule->r_dsfield = frh->tos;
rule->ce_mask |= RULE_ATTR_DSFIELD;
}
if (tb[FRA_TABLE]) {
rule->r_table = nla_get_u32(tb[FRA_TABLE]);
rule->ce_mask |= RULE_ATTR_TABLE;
}
if (tb[FRA_IIFNAME]) {
nla_strlcpy(rule->r_iifname, tb[FRA_IIFNAME], IFNAMSIZ);
rule->ce_mask |= RULE_ATTR_IIFNAME;
}
if (tb[FRA_OIFNAME]) {
nla_strlcpy(rule->r_oifname, tb[FRA_OIFNAME], IFNAMSIZ);
rule->ce_mask |= RULE_ATTR_OIFNAME;
}
if (tb[FRA_PRIORITY]) {
rule->r_prio = nla_get_u32(tb[FRA_PRIORITY]);
rule->ce_mask |= RULE_ATTR_PRIO;
}
if (tb[FRA_FWMARK]) {
rule->r_mark = nla_get_u32(tb[FRA_FWMARK]);
rule->ce_mask |= RULE_ATTR_MARK;
}
if (tb[FRA_FWMASK]) {
rule->r_mask = nla_get_u32(tb[FRA_FWMASK]);
rule->ce_mask |= RULE_ATTR_MASK;
}
if (tb[FRA_GOTO]) {
rule->r_goto = nla_get_u32(tb[FRA_GOTO]);
rule->ce_mask |= RULE_ATTR_GOTO;
}
if (tb[FRA_SRC]) {
if (!(rule->r_src = nl_addr_alloc_attr(tb[FRA_SRC], family)))
goto errout_enomem;
nl_addr_set_prefixlen(rule->r_src, frh->src_len);
rule->ce_mask |= RULE_ATTR_SRC;
}
if (tb[FRA_DST]) {
if (!(rule->r_dst = nl_addr_alloc_attr(tb[FRA_DST], family)))
goto errout_enomem;
nl_addr_set_prefixlen(rule->r_dst, frh->dst_len);
rule->ce_mask |= RULE_ATTR_DST;
}
/* ipv4 only */
if (tb[FRA_FLOW]) {
rule->r_flow = nla_get_u32(tb[FRA_FLOW]);
rule->ce_mask |= RULE_ATTR_FLOW;
}
err = pp->pp_cb((struct nl_object *) rule, pp);
errout:
rtnl_rule_put(rule);
return err;
errout_enomem:
err = -NLE_NOMEM;
goto errout;
}
static int rule_request_update(struct nl_cache *c, struct nl_sock *h)
{
return nl_rtgen_request(h, RTM_GETRULE, AF_UNSPEC, NLM_F_DUMP);
}
static void rule_dump_line(struct nl_object *o, struct nl_dump_params *p)
{
struct rtnl_rule *r = (struct rtnl_rule *) o;
char buf[128];
nl_dump_line(p, "%8d ", (r->ce_mask & RULE_ATTR_PRIO) ? r->r_prio : 0);
nl_dump(p, "%s ", nl_af2str(r->r_family, buf, sizeof(buf)));
if (r->ce_mask & RULE_ATTR_SRC)
nl_dump(p, "from %s ",
nl_addr2str(r->r_src, buf, sizeof(buf)));
if (r->ce_mask & RULE_ATTR_DST)
nl_dump(p, "to %s ",
nl_addr2str(r->r_dst, buf, sizeof(buf)));
if (r->ce_mask & RULE_ATTR_DSFIELD)
nl_dump(p, "tos %u ", r->r_dsfield);
if (r->ce_mask & (RULE_ATTR_MARK | RULE_ATTR_MASK))
nl_dump(p, "mark %#x/%#x", r->r_mark, r->r_mask);
if (r->ce_mask & RULE_ATTR_IIFNAME)
nl_dump(p, "iif %s ", r->r_iifname);
if (r->ce_mask & RULE_ATTR_OIFNAME)
nl_dump(p, "oif %s ", r->r_oifname);
if (r->ce_mask & RULE_ATTR_TABLE)
nl_dump(p, "lookup %s ",
rtnl_route_table2str(r->r_table, buf, sizeof(buf)));
if (r->ce_mask & RULE_ATTR_FLOW)
nl_dump(p, "flow %s ",
rtnl_realms2str(r->r_flow, buf, sizeof(buf)));
if (r->ce_mask & RULE_ATTR_GOTO)
nl_dump(p, "goto %u ", r->r_goto);
if (r->ce_mask & RULE_ATTR_ACTION)
nl_dump(p, "action %s",
nl_rtntype2str(r->r_action, buf, sizeof(buf)));
nl_dump(p, "\n");
}
static void rule_dump_details(struct nl_object *obj, struct nl_dump_params *p)
{
rule_dump_line(obj, p);
}
static void rule_dump_stats(struct nl_object *obj, struct nl_dump_params *p)
{
rule_dump_details(obj, p);
}
#define RULE_ATTR_FLAGS 0x0008
static int rule_compare(struct nl_object *_a, struct nl_object *_b,
uint32_t attrs, int flags)
{
struct rtnl_rule *a = (struct rtnl_rule *) _a;
struct rtnl_rule *b = (struct rtnl_rule *) _b;
int diff = 0;
#define RULE_DIFF(ATTR, EXPR) ATTR_DIFF(attrs, RULE_ATTR_##ATTR, a, b, EXPR)
diff |= RULE_DIFF(FAMILY, a->r_family != b->r_family);
diff |= RULE_DIFF(TABLE, a->r_table != b->r_table);
diff |= RULE_DIFF(ACTION, a->r_action != b->r_action);
diff |= RULE_DIFF(IIFNAME, strcmp(a->r_iifname, b->r_iifname));
diff |= RULE_DIFF(OIFNAME, strcmp(a->r_oifname, b->r_oifname));
diff |= RULE_DIFF(PRIO, a->r_prio != b->r_prio);
diff |= RULE_DIFF(MARK, a->r_mark != b->r_mark);
diff |= RULE_DIFF(MASK, a->r_mask != b->r_mask);
diff |= RULE_DIFF(GOTO, a->r_goto != b->r_goto);
diff |= RULE_DIFF(SRC, nl_addr_cmp(a->r_src, b->r_src));
diff |= RULE_DIFF(DST, nl_addr_cmp(a->r_dst, b->r_dst));
diff |= RULE_DIFF(DSFIELD, a->r_dsfield != b->r_dsfield);
diff |= RULE_DIFF(FLOW, a->r_flow != b->r_flow);
#undef RULE_DIFF
return diff;
}
static const struct trans_tbl rule_attrs[] = {
__ADD(RULE_ATTR_FAMILY, family)
__ADD(RULE_ATTR_TABLE, table)
__ADD(RULE_ATTR_ACTION, action)
__ADD(RULE_ATTR_IIFNAME, iifname)
__ADD(RULE_ATTR_OIFNAME, oifname)
__ADD(RULE_ATTR_PRIO, prio)
__ADD(RULE_ATTR_MARK, mark)
__ADD(RULE_ATTR_MASK, mask)
__ADD(RULE_ATTR_GOTO, goto)
__ADD(RULE_ATTR_SRC, src)
__ADD(RULE_ATTR_DST, dst)
__ADD(RULE_ATTR_DSFIELD, dsfield)
__ADD(RULE_ATTR_FLOW, flow)
};
static char *rule_attrs2str(int attrs, char *buf, size_t len)
{
return __flags2str(attrs, buf, len, rule_attrs,
ARRAY_SIZE(rule_attrs));
}
/**
* @name Allocation/Freeing
* @{
*/
struct rtnl_rule *rtnl_rule_alloc(void)
{
return (struct rtnl_rule *) nl_object_alloc(&rule_obj_ops);
}
void rtnl_rule_put(struct rtnl_rule *rule)
{
nl_object_put((struct nl_object *) rule);
}
/** @} */
/**
* @name Cache Management
* @{
*/
/**
* Build a rule cache including all rules currently configured in the kernel.
* @arg sock Netlink socket.
* @arg family Address family or AF_UNSPEC.
* @arg result Pointer to store resulting cache.
*
* Allocates a new rule cache, initializes it properly and updates it
* to include all rules currently configured in the kernel.
*
* @return 0 on success or a negative error code.
*/
int rtnl_rule_alloc_cache(struct nl_sock *sock, int family,
struct nl_cache **result)
{
struct nl_cache * cache;
int err;
if (!(cache = nl_cache_alloc(&rtnl_rule_ops)))
return -NLE_NOMEM;
cache->c_iarg1 = family;
if (sock && (err = nl_cache_refill(sock, cache)) < 0) {
free(cache);
return err;
}
*result = cache;
return 0;
}
/** @} */
/**
* @name Rule Addition
* @{
*/
static int build_rule_msg(struct rtnl_rule *tmpl, int cmd, int flags,
struct nl_msg **result)
{
struct nl_msg *msg;
struct fib_rule_hdr frh = {
.family = tmpl->r_family,
.table = tmpl->r_table,
.action = tmpl->r_action,
.flags = tmpl->r_flags,
.tos = tmpl->r_dsfield,
};
if (!(tmpl->ce_mask & RULE_ATTR_FAMILY))
return -NLE_MISSING_ATTR;
msg = nlmsg_alloc_simple(cmd, flags);
if (!msg)
return -NLE_NOMEM;
if (tmpl->ce_mask & RULE_ATTR_SRC)
frh.src_len = nl_addr_get_prefixlen(tmpl->r_src);
if (tmpl->ce_mask & RULE_ATTR_DST)
frh.dst_len = nl_addr_get_prefixlen(tmpl->r_dst);
if (nlmsg_append(msg, &frh, sizeof(frh), NLMSG_ALIGNTO) < 0)
goto nla_put_failure;
/* Additional table attribute replacing the 8bit in the header, was
* required to allow more than 256 tables. */
NLA_PUT_U32(msg, FRA_TABLE, tmpl->r_table);
if (tmpl->ce_mask & RULE_ATTR_SRC)
NLA_PUT_ADDR(msg, FRA_SRC, tmpl->r_src);
if (tmpl->ce_mask & RULE_ATTR_DST)
NLA_PUT_ADDR(msg, FRA_DST, tmpl->r_dst);
if (tmpl->ce_mask & RULE_ATTR_IIFNAME)
NLA_PUT_STRING(msg, FRA_IIFNAME, tmpl->r_iifname);
if (tmpl->ce_mask & RULE_ATTR_OIFNAME)
NLA_PUT_STRING(msg, FRA_OIFNAME, tmpl->r_oifname);
if (tmpl->ce_mask & RULE_ATTR_PRIO)
NLA_PUT_U32(msg, FRA_PRIORITY, tmpl->r_prio);
if (tmpl->ce_mask & RULE_ATTR_MARK)
NLA_PUT_U32(msg, FRA_FWMARK, tmpl->r_mark);
if (tmpl->ce_mask & RULE_ATTR_MASK)
NLA_PUT_U32(msg, FRA_FWMASK, tmpl->r_mask);
if (tmpl->ce_mask & RULE_ATTR_GOTO)
NLA_PUT_U32(msg, FRA_GOTO, tmpl->r_goto);
if (tmpl->ce_mask & RULE_ATTR_FLOW)
NLA_PUT_U32(msg, FRA_FLOW, tmpl->r_flow);
*result = msg;
return 0;
nla_put_failure:
nlmsg_free(msg);
return -NLE_MSGSIZE;
}
/**
* Build netlink request message to add a new rule
* @arg tmpl template with data of new rule
* @arg flags additional netlink message flags
* @arg result Result pointer
*
* Builds a new netlink message requesting a addition of a new
* rule. The netlink message header isn't fully equipped with
* all relevant fields and must thus be sent out via nl_send_auto_complete()
* or supplemented as needed. \a tmpl must contain the attributes of the new
* address set via \c rtnl_rule_set_* functions.
*
* @return 0 on success or a negative error code.
*/
int rtnl_rule_build_add_request(struct rtnl_rule *tmpl, int flags,
struct nl_msg **result)
{
return build_rule_msg(tmpl, RTM_NEWRULE, NLM_F_CREATE | flags,
result);
}
/**
* Add a new rule
* @arg sk Netlink socket.
* @arg tmpl template with requested changes
* @arg flags additional netlink message flags
*
* Builds a netlink message by calling rtnl_rule_build_add_request(),
* sends the request to the kernel and waits for the next ACK to be
* received and thus blocks until the request has been fullfilled.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_rule_add(struct nl_sock *sk, struct rtnl_rule *tmpl, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_rule_build_add_request(tmpl, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
/** @} */
/**
* @name Rule Deletion
* @{
*/
/**
* Build a netlink request message to delete a rule
* @arg rule rule to delete
* @arg flags additional netlink message flags
* @arg result Result pointer
*
* Builds a new netlink message requesting a deletion of a rule.
* The netlink message header isn't fully equipped with all relevant
* fields and must thus be sent out via nl_send_auto_complete()
* or supplemented as needed. \a rule must point to an existing
* address.
*
* @return 0 on success or a negative error code.
*/
int rtnl_rule_build_delete_request(struct rtnl_rule *rule, int flags,
struct nl_msg **result)
{
return build_rule_msg(rule, RTM_DELRULE, flags, result);
}
/**
* Delete a rule
* @arg sk Netlink socket.
* @arg rule rule to delete
* @arg flags additional netlink message flags
*
* Builds a netlink message by calling rtnl_rule_build_delete_request(),
* sends the request to the kernel and waits for the next ACK to be
* received and thus blocks until the request has been fullfilled.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_rule_delete(struct nl_sock *sk, struct rtnl_rule *rule, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_rule_build_delete_request(rule, flags, &msg)) < 0)
return err;
err = nl_send_auto_complete(sk, msg);
nlmsg_free(msg);
if (err < 0)
return err;
return wait_for_ack(sk);
}
/** @} */
/**
* @name Attribute Modification
* @{
*/
void rtnl_rule_set_family(struct rtnl_rule *rule, int family)
{
rule->r_family = family;
rule->ce_mask |= RULE_ATTR_FAMILY;
}
int rtnl_rule_get_family(struct rtnl_rule *rule)
{
if (rule->ce_mask & RULE_ATTR_FAMILY)
return rule->r_family;
else
return AF_UNSPEC;
}
void rtnl_rule_set_prio(struct rtnl_rule *rule, uint32_t prio)
{
rule->r_prio = prio;
rule->ce_mask |= RULE_ATTR_PRIO;
}
uint32_t rtnl_rule_get_prio(struct rtnl_rule *rule)
{
return rule->r_prio;
}
void rtnl_rule_set_mark(struct rtnl_rule *rule, uint32_t mark)
{
rule->r_mark = mark;
rule->ce_mask |= RULE_ATTR_MARK;
}
uint32_t rtnl_rule_get_mark(struct rtnl_rule *rule)
{
return rule->r_mark;
}
void rtnl_rule_set_mask(struct rtnl_rule *rule, uint32_t mask)
{
rule->r_mask = mask;
rule->ce_mask |= RULE_ATTR_MASK;
}
uint32_t rtnl_rule_get_mask(struct rtnl_rule *rule)
{
return rule->r_mask;
}
void rtnl_rule_set_table(struct rtnl_rule *rule, uint32_t table)
{
rule->r_table = table;
rule->ce_mask |= RULE_ATTR_TABLE;
}
uint32_t rtnl_rule_get_table(struct rtnl_rule *rule)
{
return rule->r_table;
}
void rtnl_rule_set_dsfield(struct rtnl_rule *rule, uint8_t dsfield)
{
rule->r_dsfield = dsfield;
rule->ce_mask |= RULE_ATTR_DSFIELD;
}
uint8_t rtnl_rule_get_dsfield(struct rtnl_rule *rule)
{
return rule->r_dsfield;
}
static inline int __assign_addr(struct rtnl_rule *rule, struct nl_addr **pos,
struct nl_addr *new, int flag)
{
if (rule->ce_mask & RULE_ATTR_FAMILY) {
if (new->a_family != rule->r_family)
return -NLE_AF_MISMATCH;
} else
rule->r_family = new->a_family;
if (*pos)
nl_addr_put(*pos);
nl_addr_get(new);
*pos = new;
rule->ce_mask |= (flag | RULE_ATTR_FAMILY);
return 0;
}
int rtnl_rule_set_src(struct rtnl_rule *rule, struct nl_addr *src)
{
return __assign_addr(rule, &rule->r_src, src, RULE_ATTR_SRC);
}
struct nl_addr *rtnl_rule_get_src(struct rtnl_rule *rule)
{
return rule->r_src;
}
int rtnl_rule_set_dst(struct rtnl_rule *rule, struct nl_addr *dst)
{
return __assign_addr(rule, &rule->r_dst, dst, RULE_ATTR_DST);
}
struct nl_addr *rtnl_rule_get_dst(struct rtnl_rule *rule)
{
return rule->r_dst;
}
int rtnl_rule_set_iif(struct rtnl_rule *rule, const char *dev)
{
if (strlen(dev) > IFNAMSIZ-1)
return -NLE_RANGE;
strcpy(rule->r_iifname, dev);
rule->ce_mask |= RULE_ATTR_IIFNAME;
return 0;
}
char *rtnl_rule_get_iif(struct rtnl_rule *rule)
{
if (rule->ce_mask & RULE_ATTR_IIFNAME)
return rule->r_iifname;
else
return NULL;
}
int rtnl_rule_set_oif(struct rtnl_rule *rule, const char *dev)
{
if (strlen(dev) > IFNAMSIZ-1)
return -NLE_RANGE;
strcpy(rule->r_oifname, dev);
rule->ce_mask |= RULE_ATTR_OIFNAME;
return 0;
}
char *rtnl_rule_get_oif(struct rtnl_rule *rule)
{
if (rule->ce_mask & RULE_ATTR_OIFNAME)
return rule->r_oifname;
else
return NULL;
}
void rtnl_rule_set_action(struct rtnl_rule *rule, uint8_t action)
{
rule->r_action = action;
rule->ce_mask |= RULE_ATTR_ACTION;
}
uint8_t rtnl_rule_get_action(struct rtnl_rule *rule)
{
return rule->r_action;
}
void rtnl_rule_set_realms(struct rtnl_rule *rule, uint32_t realms)
{
rule->r_flow = realms;
rule->ce_mask |= RULE_ATTR_FLOW;
}
uint32_t rtnl_rule_get_realms(struct rtnl_rule *rule)
{
return rule->r_flow;
}
void rtnl_rule_set_goto(struct rtnl_rule *rule, uint32_t ref)
{
rule->r_goto = ref;
rule->ce_mask |= RULE_ATTR_GOTO;
}
uint32_t rtnl_rule_get_goto(struct rtnl_rule *rule)
{
return rule->r_goto;
}
/** @} */
static struct nl_object_ops rule_obj_ops = {
.oo_name = "route/rule",
.oo_size = sizeof(struct rtnl_rule),
.oo_free_data = rule_free_data,
.oo_clone = rule_clone,
.oo_dump = {
[NL_DUMP_LINE] = rule_dump_line,
[NL_DUMP_DETAILS] = rule_dump_details,
[NL_DUMP_STATS] = rule_dump_stats,
},
.oo_compare = rule_compare,
.oo_attrs2str = rule_attrs2str,
.oo_id_attrs = ~0,
};
static struct nl_cache_ops rtnl_rule_ops = {
.co_name = "route/rule",
.co_hdrsize = sizeof(struct fib_rule_hdr),
.co_msgtypes = {
{ RTM_NEWRULE, NL_ACT_NEW, "new" },
{ RTM_DELRULE, NL_ACT_DEL, "del" },
{ RTM_GETRULE, NL_ACT_GET, "get" },
END_OF_MSGTYPES_LIST,
},
.co_protocol = NETLINK_ROUTE,
.co_request_update = rule_request_update,
.co_msg_parser = rule_msg_parser,
.co_obj_ops = &rule_obj_ops,
};
static void __init rule_init(void)
{
nl_cache_mngt_register(&rtnl_rule_ops);
}
static void __exit rule_exit(void)
{
nl_cache_mngt_unregister(&rtnl_rule_ops);
}
/** @} */