libnl 1.1
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Modules | |
Link Info API | |
Defines | |
#define | RTNL_LINK_NOT_FOUND -1 |
Special interface index stating the link was not found. | |
Allocation/Freeing | |
struct rtnl_link * | rtnl_link_alloc (void) |
void | rtnl_link_put (struct rtnl_link *link) |
Cache Management | |
struct nl_cache * | rtnl_link_alloc_cache (struct nl_handle *handle) |
Allocate link cache and fill in all configured links. | |
struct rtnl_link * | rtnl_link_get (struct nl_cache *cache, int ifindex) |
Look up link by interface index in the provided cache. | |
struct rtnl_link * | rtnl_link_get_by_name (struct nl_cache *cache, const char *name) |
Look up link by link name in the provided cache. | |
Link Modifications | |
struct nl_msg * | rtnl_link_build_change_request (struct rtnl_link *old, struct rtnl_link *tmpl, int flags) |
Builds a netlink change request message to change link attributes. | |
int | rtnl_link_change (struct nl_handle *handle, struct rtnl_link *old, struct rtnl_link *tmpl, int flags) |
Change link attributes. | |
Name <-> Index Translations | |
char * | rtnl_link_i2name (struct nl_cache *cache, int ifindex, char *dst, size_t len) |
Translate an interface index to the corresponding link name. | |
int | rtnl_link_name2i (struct nl_cache *cache, const char *name) |
Translate a link name to the corresponding interface index. | |
Link Flags Translations | |
char * | rtnl_link_flags2str (int flags, char *buf, size_t len) |
int | rtnl_link_str2flags (const char *name) |
Link Statistics Translations | |
char * | rtnl_link_stat2str (int st, char *buf, size_t len) |
int | rtnl_link_str2stat (const char *name) |
Link Operstate Translations | |
char * | rtnl_link_operstate2str (int st, char *buf, size_t len) |
int | rtnl_link_str2operstate (const char *name) |
Link Mode Translations | |
char * | rtnl_link_mode2str (int st, char *buf, size_t len) |
int | rtnl_link_str2mode (const char *name) |
Attributes | |
void | rtnl_link_set_qdisc (struct rtnl_link *link, const char *qdisc) |
char * | rtnl_link_get_qdisc (struct rtnl_link *link) |
void | rtnl_link_set_name (struct rtnl_link *link, const char *name) |
char * | rtnl_link_get_name (struct rtnl_link *link) |
void | rtnl_link_set_addr (struct rtnl_link *link, struct nl_addr *addr) |
struct nl_addr * | rtnl_link_get_addr (struct rtnl_link *link) |
void | rtnl_link_set_broadcast (struct rtnl_link *link, struct nl_addr *brd) |
struct nl_addr * | rtnl_link_get_broadcast (struct rtnl_link *link) |
void | rtnl_link_set_flags (struct rtnl_link *link, unsigned int flags) |
void | rtnl_link_unset_flags (struct rtnl_link *link, unsigned int flags) |
unsigned int | rtnl_link_get_flags (struct rtnl_link *link) |
void | rtnl_link_set_family (struct rtnl_link *link, int family) |
int | rtnl_link_get_family (struct rtnl_link *link) |
void | rtnl_link_set_arptype (struct rtnl_link *link, unsigned int arptype) |
unsigned int | rtnl_link_get_arptype (struct rtnl_link *link) |
void | rtnl_link_set_ifindex (struct rtnl_link *link, int ifindex) |
int | rtnl_link_get_ifindex (struct rtnl_link *link) |
void | rtnl_link_set_mtu (struct rtnl_link *link, unsigned int mtu) |
unsigned int | rtnl_link_get_mtu (struct rtnl_link *link) |
void | rtnl_link_set_txqlen (struct rtnl_link *link, unsigned int txqlen) |
unsigned int | rtnl_link_get_txqlen (struct rtnl_link *link) |
void | rtnl_link_set_weight (struct rtnl_link *link, unsigned int weight) |
unsigned int | rtnl_link_get_weight (struct rtnl_link *link) |
void | rtnl_link_set_link (struct rtnl_link *link, int ifindex) |
int | rtnl_link_get_link (struct rtnl_link *link) |
void | rtnl_link_set_master (struct rtnl_link *link, int ifindex) |
int | rtnl_link_get_master (struct rtnl_link *link) |
void | rtnl_link_set_operstate (struct rtnl_link *link, uint8_t operstate) |
uint8_t | rtnl_link_get_operstate (struct rtnl_link *link) |
void | rtnl_link_set_linkmode (struct rtnl_link *link, uint8_t linkmode) |
uint8_t | rtnl_link_get_linkmode (struct rtnl_link *link) |
uint64_t | rtnl_link_get_stat (struct rtnl_link *link, int id) |
int | rtnl_link_set_info_type (struct rtnl_link *link, const char *type) |
Specify the info type of a link. | |
char * | rtnl_link_get_info_type (struct rtnl_link *link) |
Return info type of a link. |
IFF_UP Status of link (up|down) IFF_BROADCAST Indicates this link allows broadcasting IFF_MULTICAST Indicates this link allows multicasting IFF_ALLMULTI Indicates this link is doing multicast routing IFF_DEBUG Tell the driver to do debugging (currently unused) IFF_LOOPBACK This is the loopback link IFF_POINTOPOINT Point-to-point link IFF_NOARP Link is unable to perform ARP IFF_PROMISC Status of promiscious mode flag IFF_MASTER Used by teql IFF_SLAVE Used by teql IFF_PORTSEL Indicates this link allows port selection IFF_AUTOMEDIA Indicates this link selects port automatically IFF_DYNAMIC Indicates the address of this link is dynamic IFF_RUNNING Link is running and carrier is ok. IFF_NOTRAILERS Unused, BSD compat.
// The first step is to retrieve a list of all available interfaces within // the kernel and put them into a cache. struct nl_cache *cache = rtnl_link_alloc_cache(nl_handle); // In a second step, a specific link may be looked up by either interface // index or interface name. struct rtnl_link *link = rtnl_link_get_by_name(cache, "lo"); // rtnl_link_get_by_name() is the short version for translating the // interface name to an interface index first like this: int ifindex = rtnl_link_name2i(cache, "lo"); struct rtnl_link *link = rtnl_link_get(cache, ifindex); // After successful usage, the object must be given back to the cache rtnl_link_put(link);
// In order to change any attributes of an existing link, we must allocate // a new link to hold the change requests: struct rtnl_link *request = rtnl_link_alloc(); // Now we can go on and specify the attributes we want to change: rtnl_link_set_weight(request, 300); rtnl_link_set_mtu(request, 1360); // We can also shut an interface down administratively rtnl_link_unset_flags(request, rtnl_link_str2flags("up")); // Actually, we should know which link to change, so let's look it up struct rtnl_link *old = rtnl_link_get(cache, "eth0"); // Two ways exist to commit this change request, the first one is to // build the required netlink message and send it out in one single // step: rtnl_link_change(nl_handle, old, request); // An alternative way is to build the netlink message and send it // out yourself using nl_send_auto_complete() struct nl_msg *msg = rtnl_link_build_change_request(old, request); nl_send_auto_complete(nl_handle, nlmsg_hdr(msg)); nlmsg_free(msg); // Don't forget to give back the link object ;-> rtnl_link_put(old);
// Some link types offer additional parameters and statistics specific // to their type. F.e. a VLAN link can be configured like this: // // Allocate a new link and set the info type to "vlan". This is required // to prepare the link to hold vlan specific attributes. struct rtnl_link *request = rtnl_link_alloc(); rtnl_link_set_info_type(request, "vlan"); // Now vlan specific attributes can be set: rtnl_link_vlan_set_id(request, 10); rtnl_link_vlan_set_ingress_map(request, 2, 8); // Of course the attributes can also be read, check the info type // to make sure you are using the right access functions: char *type = rtnl_link_get_info_type(link); if (!strcmp(type, "vlan")) int id = rtnl_link_vlan_get_id(link);
struct nl_cache* rtnl_link_alloc_cache | ( | struct nl_handle * | handle | ) | [read] |
handle | Netlink handle. |
Allocates a new link cache, initializes it properly and updates it to include all links currently configured in the kernel.
Definition at line 869 of file link.c.
References nl_cache_alloc(), nl_cache_free(), and nl_cache_refill().
{ struct nl_cache * cache; cache = nl_cache_alloc(&rtnl_link_ops); if (cache == NULL) return NULL; if (handle && nl_cache_refill(handle, cache) < 0) { nl_cache_free(cache); return NULL; } return cache; }
struct rtnl_link* rtnl_link_get | ( | struct nl_cache * | cache, |
int | ifindex | ||
) | [read] |
cache | link cache |
ifindex | link interface index |
The caller owns a reference on the returned object and must give the object back via rtnl_link_put().
Definition at line 895 of file link.c.
References nl_object_get().
Referenced by rtnl_link_i2name().
{ struct rtnl_link *link; if (cache->c_ops != &rtnl_link_ops) return NULL; nl_list_for_each_entry(link, &cache->c_items, ce_list) { if (link->l_index == ifindex) { nl_object_get((struct nl_object *) link); return link; } } return NULL; }
struct rtnl_link* rtnl_link_get_by_name | ( | struct nl_cache * | cache, |
const char * | name | ||
) | [read] |
cache | link cache |
name | link name |
The caller owns a reference on the returned object and must give the object back via rtnl_link_put().
Definition at line 922 of file link.c.
References nl_object_get().
Referenced by rtnl_link_name2i().
{ struct rtnl_link *link; if (cache->c_ops != &rtnl_link_ops) return NULL; nl_list_for_each_entry(link, &cache->c_items, ce_list) { if (!strcmp(name, link->l_name)) { nl_object_get((struct nl_object *) link); return link; } } return NULL; }
struct nl_msg* rtnl_link_build_change_request | ( | struct rtnl_link * | old, |
struct rtnl_link * | tmpl, | ||
int | flags | ||
) | [read] |
old | link to be changed |
tmpl | template with requested changes |
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. old must point to a link currently configured in the kernel and tmpl must contain the attributes to be changed set via rtnl_link_set_*
functions.
Definition at line 965 of file link.c.
References nla_nest_end(), nla_nest_start(), NLA_PUT_ADDR, NLA_PUT_STRING, NLA_PUT_U32, NLA_PUT_U8, nlmsg_alloc_simple(), nlmsg_append(), and nlmsg_free().
Referenced by rtnl_link_change().
{ struct nl_msg *msg; struct ifinfomsg ifi = { .ifi_family = old->l_family, .ifi_index = old->l_index, }; if (tmpl->ce_mask & LINK_ATTR_FLAGS) { ifi.ifi_flags = old->l_flags & ~tmpl->l_flag_mask; ifi.ifi_flags |= tmpl->l_flags; } msg = nlmsg_alloc_simple(RTM_SETLINK, flags); if (!msg) goto nla_put_failure; if (nlmsg_append(msg, &ifi, sizeof(ifi), NLMSG_ALIGNTO) < 0) goto nla_put_failure; if (tmpl->ce_mask & LINK_ATTR_ADDR) NLA_PUT_ADDR(msg, IFLA_ADDRESS, tmpl->l_addr); if (tmpl->ce_mask & LINK_ATTR_BRD) NLA_PUT_ADDR(msg, IFLA_BROADCAST, tmpl->l_bcast); if (tmpl->ce_mask & LINK_ATTR_MTU) NLA_PUT_U32(msg, IFLA_MTU, tmpl->l_mtu); if (tmpl->ce_mask & LINK_ATTR_TXQLEN) NLA_PUT_U32(msg, IFLA_TXQLEN, tmpl->l_txqlen); if (tmpl->ce_mask & LINK_ATTR_WEIGHT) NLA_PUT_U32(msg, IFLA_WEIGHT, tmpl->l_weight); if (tmpl->ce_mask & LINK_ATTR_IFNAME) NLA_PUT_STRING(msg, IFLA_IFNAME, tmpl->l_name); if (tmpl->ce_mask & LINK_ATTR_OPERSTATE) NLA_PUT_U8(msg, IFLA_OPERSTATE, tmpl->l_operstate); if (tmpl->ce_mask & LINK_ATTR_LINKMODE) NLA_PUT_U8(msg, IFLA_LINKMODE, tmpl->l_linkmode); if ((tmpl->ce_mask & LINK_ATTR_LINKINFO) && tmpl->l_info_ops && tmpl->l_info_ops->io_put_attrs) { struct nlattr *info; if (!(info = nla_nest_start(msg, IFLA_LINKINFO))) goto nla_put_failure; NLA_PUT_STRING(msg, IFLA_INFO_KIND, tmpl->l_info_ops->io_name); if (tmpl->l_info_ops->io_put_attrs(msg, tmpl) < 0) goto nla_put_failure; nla_nest_end(msg, info); } return msg; nla_put_failure: nlmsg_free(msg); return NULL; }
int rtnl_link_change | ( | struct nl_handle * | handle, |
struct rtnl_link * | old, | ||
struct rtnl_link * | tmpl, | ||
int | flags | ||
) |
handle | netlink handle |
old | link to be changed |
tmpl | template with requested changes |
flags | additional netlink message flags |
Builds a new netlink message by calling rtnl_link_build_change_request(), sends the request to the kernel and waits for the next ACK to be received, i.e. blocks until the request has been processed.
Definition at line 1048 of file link.c.
References nl_send_auto_complete(), nl_wait_for_ack(), nlmsg_free(), and rtnl_link_build_change_request().
{ int err; struct nl_msg *msg; msg = rtnl_link_build_change_request(old, tmpl, flags); if (!msg) return nl_errno(ENOMEM); err = nl_send_auto_complete(handle, msg); if (err < 0) return err; nlmsg_free(msg); return nl_wait_for_ack(handle); }
char* rtnl_link_i2name | ( | struct nl_cache * | cache, |
int | ifindex, | ||
char * | dst, | ||
size_t | len | ||
) |
cache | link cache |
ifindex | link interface index |
dst | destination buffer |
len | length of destination buffer |
Translates the specified interface index to the corresponding link name and stores the name in the destination buffer.
Definition at line 1085 of file link.c.
References rtnl_link_get().
{ struct rtnl_link *link = rtnl_link_get(cache, ifindex); if (link) { strncpy(dst, link->l_name, len - 1); rtnl_link_put(link); return dst; } return NULL; }
int rtnl_link_name2i | ( | struct nl_cache * | cache, |
const char * | name | ||
) |
cache | link cache |
name | link name |
Definition at line 1106 of file link.c.
References rtnl_link_get_by_name(), and RTNL_LINK_NOT_FOUND.
{ int ifindex = RTNL_LINK_NOT_FOUND; struct rtnl_link *link; link = rtnl_link_get_by_name(cache, name); if (link) { ifindex = link->l_index; rtnl_link_put(link); } return ifindex; }
int rtnl_link_set_info_type | ( | struct rtnl_link * | link, |
const char * | type | ||
) |
link | link object |
type | info type |
Looks up the info type and prepares the link to store info type specific attributes. If an info type has been assigned already it will be released with all changes lost.
Definition at line 1501 of file link.c.
References rtnl_link_info_ops::io_alloc.
{ struct rtnl_link_info_ops *io; int err; if ((io = rtnl_link_info_ops_lookup(type)) == NULL) return nl_error(ENOENT, "No such link info type exists"); if (link->l_info_ops) release_link_info(link); if ((err = io->io_alloc(link)) < 0) return err; link->l_info_ops = io; return 0; }
char* rtnl_link_get_info_type | ( | struct rtnl_link * | link | ) |