/**
* Builds a netlink request message to do a lookup
* @arg req Requested match.
* @arg flags additional netlink message flags
*
* Builds a new netlink message requesting a change of link attributes.
* The netlink message header isn't fully equipped with all relevant
* fields and must be sent out via nl_send_auto_complete() or
* supplemented as needed.
* \a old must point to a link currently configured in the kernel
* and \a tmpl must contain the attributes to be changed set via
* \c rtnl_link_set_* functions.
*
* @return New netlink message
* @note Not all attributes can be changed, see
* \ref link_changeable "Changeable Attributes" for more details.
*/
struct nl_msg *flnl_lookup_build_request(struct flnl_request *req, int flags)
{
struct nl_msg *msg;
struct nl_addr *addr;
uint64_t fwmark;
int tos, scope, table;
struct fib_result_nl fr = {0};
fwmark = flnl_request_get_fwmark(req);
tos = flnl_request_get_tos(req);
scope = flnl_request_get_scope(req);
table = flnl_request_get_table(req);
fr.fl_fwmark = fwmark != UINT_LEAST64_MAX ? fwmark : 0;
fr.fl_tos = tos >= 0 ? tos : 0;
fr.fl_scope = scope >= 0 ? scope : RT_SCOPE_UNIVERSE;
fr.tb_id_in = table >= 0 ? table : RT_TABLE_UNSPEC;
addr = flnl_request_get_addr(req);
if (!addr) {
nl_error(EINVAL, "Request must specify the address");
return NULL;
}
fr.fl_addr = *(uint32_t *) nl_addr_get_binary_addr(addr);
msg = nlmsg_alloc_simple(0, flags);
if (!msg)
goto errout;
if (nlmsg_append(msg, &fr, sizeof(fr), NLMSG_ALIGNTO) < 0)
goto errout;
return msg;
errout:
nlmsg_free(msg);
return NULL;
}
/**
* Builds a netlink request message to do a lookup
* @arg req Requested match.
* @arg flags additional netlink message flags
* @arg result Result pointer
*
* Builds a new netlink message requesting a change of link attributes.
* The netlink message header isn't fully equipped with all relevant
* fields and must be sent out via nl_send_auto_complete() or
* supplemented as needed.
* \a old must point to a link currently configured in the kernel
* and \a tmpl must contain the attributes to be changed set via
* \c rtnl_link_set_* functions.
*
* @return 0 on success or a negative error code.
*/
int flnl_lookup_build_request(struct flnl_request *req, int flags,
struct nl_msg **result)
{
struct nl_msg *msg;
struct nl_addr *addr;
uint64_t fwmark;
int tos, scope, table;
struct fib_result_nl fr = {0};
fwmark = flnl_request_get_fwmark(req);
tos = flnl_request_get_tos(req);
scope = flnl_request_get_scope(req);
table = flnl_request_get_table(req);
fr.fl_fwmark = fwmark != UINT_LEAST64_MAX ? fwmark : 0;
fr.fl_tos = tos >= 0 ? tos : 0;
fr.fl_scope = scope >= 0 ? scope : RT_SCOPE_UNIVERSE;
fr.tb_id_in = table >= 0 ? table : RT_TABLE_UNSPEC;
addr = flnl_request_get_addr(req);
if (!addr)
return -NLE_MISSING_ATTR;
fr.fl_addr = *(uint32_t *) nl_addr_get_binary_addr(addr);
msg = nlmsg_alloc_simple(0, flags);
if (!msg)
return -NLE_NOMEM;
if (nlmsg_append(msg, &fr, sizeof(fr), NLMSG_ALIGNTO) < 0)
goto errout;
*result = msg;
return 0;
errout:
nlmsg_free(msg);
return -NLE_MSGSIZE;
}
