libnl 1.1
|
Netlink Message Construction/Parsing Interface. More...
Data Structures | |
struct | nlmsghdr |
Netlink message header. More... | |
struct | nlmsgerr |
Netlink error message. More... | |
Modules | |
Attributes | |
Netlink Attributes Construction/Parsing Interface. | |
Defines | |
#define | NL_AUTO_PID 0 |
Will cause the netlink pid to be set to the pid assigned to the netlink handle (socket) just before sending the message off. | |
#define | NL_AUTO_SEQ 0 |
May be used to refer to a sequence number which should be automatically set just before sending the message off. | |
Size Calculations | |
int | nlmsg_msg_size (int payload) |
length of netlink message not including padding | |
int | nlmsg_total_size (int payload) |
length of netlink message including padding | |
int | nlmsg_padlen (int payload) |
length of padding at the message's tail | |
Payload Access | |
void * | nlmsg_data (const struct nlmsghdr *nlh) |
head of message payload | |
void * | nlmsg_tail (const struct nlmsghdr *nlh) |
int | nlmsg_len (const struct nlmsghdr *nlh) |
length of message payload | |
Attribute Access | |
struct nlattr * | nlmsg_attrdata (const struct nlmsghdr *nlh, int hdrlen) |
head of attributes data | |
int | nlmsg_attrlen (const struct nlmsghdr *nlh, int hdrlen) |
length of attributes data | |
Message Parsing | |
int | nlmsg_valid_hdr (const struct nlmsghdr *nlh, int hdrlen) |
int | nlmsg_ok (const struct nlmsghdr *nlh, int remaining) |
check if the netlink message fits into the remaining bytes | |
struct nlmsghdr * | nlmsg_next (struct nlmsghdr *nlh, int *remaining) |
next netlink message in message stream | |
int | nlmsg_parse (struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[], int maxtype, struct nla_policy *policy) |
parse attributes of a netlink message | |
struct nlattr * | nlmsg_find_attr (struct nlmsghdr *nlh, int hdrlen, int attrtype) |
nlmsg_find_attr - find a specific attribute in a netlink message | |
int | nlmsg_validate (struct nlmsghdr *nlh, int hdrlen, int maxtype, struct nla_policy *policy) |
nlmsg_validate - validate a netlink message including attributes | |
Message Building/Access | |
struct nl_msg * | nlmsg_alloc (void) |
Allocate a new netlink message with the default maximum payload size. | |
struct nl_msg * | nlmsg_alloc_size (size_t max) |
Allocate a new netlink message with maximum payload size specified. | |
struct nl_msg * | nlmsg_inherit (struct nlmsghdr *hdr) |
Allocate a new netlink message and inherit netlink message header. | |
struct nl_msg * | nlmsg_alloc_simple (int nlmsgtype, int flags) |
Allocate a new netlink message. | |
void | nlmsg_set_default_size (size_t max) |
Set the default maximum message payload size for allocated messages. | |
struct nl_msg * | nlmsg_convert (struct nlmsghdr *hdr) |
Convert a netlink message received from a netlink socket to a nl_msg. | |
void * | nlmsg_reserve (struct nl_msg *n, size_t len, int pad) |
Reserve room for additional data in a netlink message. | |
int | nlmsg_append (struct nl_msg *n, void *data, size_t len, int pad) |
Append data to tail of a netlink message. | |
int | nlmsg_expand (struct nl_msg *n, size_t newlen) |
Expand maximum payload size of a netlink message. | |
struct nlmsghdr * | nlmsg_put (struct nl_msg *n, uint32_t pid, uint32_t seq, int type, int payload, int flags) |
Add a netlink message header to a netlink message. | |
struct nlmsghdr * | nlmsg_hdr (struct nl_msg *n) |
Return actual netlink message. | |
void | nlmsg_free (struct nl_msg *n) |
Free a netlink message. | |
Attributes | |
void | nlmsg_set_proto (struct nl_msg *msg, int protocol) |
int | nlmsg_get_proto (struct nl_msg *msg) |
size_t | nlmsg_get_max_size (struct nl_msg *msg) |
void | nlmsg_set_src (struct nl_msg *msg, struct sockaddr_nl *addr) |
struct sockaddr_nl * | nlmsg_get_src (struct nl_msg *msg) |
void | nlmsg_set_dst (struct nl_msg *msg, struct sockaddr_nl *addr) |
struct sockaddr_nl * | nlmsg_get_dst (struct nl_msg *msg) |
void | nlmsg_set_creds (struct nl_msg *msg, struct ucred *creds) |
struct ucred * | nlmsg_get_creds (struct nl_msg *msg) |
Netlink Message Type Translations | |
char * | nl_nlmsgtype2str (int type, char *buf, size_t size) |
int | nl_str2nlmsgtype (const char *name) |
Netlink Message Flags Translations | |
char * | nl_nlmsg_flags2str (int flags, char *buf, size_t len) |
Direct Parsing | |
int | nl_msg_parse (struct nl_msg *msg, void(*cb)(struct nl_object *, void *), void *arg) |
Dumping | |
void | nl_msg_dump (struct nl_msg *msg, FILE *ofd) |
Dump message in human readable format to file descriptor. | |
Iterators | |
#define | nlmsg_for_each_attr(pos, nlh, hdrlen, rem) |
Iterate over a stream of attributes in a message. | |
#define | nlmsg_for_each_msg(pos, head, len, rem) |
Iterate over a stream of messages. | |
Standard message flags | |
#define | NLM_F_REQUEST 1 |
Must be set on all request messages (typically from user space to kernel space). | |
#define | NLM_F_MULTI 2 |
Indicates the message is part of a multipart message terminated by NLMSG_DONE. | |
#define | NLM_F_ACK 4 |
Request for an acknowledgment on success. | |
#define | NLM_F_ECHO 8 |
Echo this request. | |
Additional message flags for GET requests | |
#define | NLM_F_ROOT 0x100 |
Return the complete table instead of a single entry. | |
#define | NLM_F_MATCH 0x200 |
Return all entries matching criteria passed in message content. | |
#define | NLM_F_ATOMIC 0x400 |
Return an atomic snapshot of the table being referenced. | |
#define | NLM_F_DUMP (NLM_F_ROOT|NLM_F_MATCH) |
Dump all entries. | |
Additional messsage flags for NEW requests | |
#define | NLM_F_REPLACE 0x100 |
Replace existing matching config object with this request. | |
#define | NLM_F_EXCL 0x200 |
Don't replace the config object if it already exists. | |
#define | NLM_F_CREATE 0x400 |
Create config object if it doesn't already exist. | |
#define | NLM_F_APPEND 0x800 |
Add to the end of the object list. | |
Standard Message types | |
#define | NLMSG_NOOP 0x1 |
No operation, message must be ignored. | |
#define | NLMSG_ERROR 0x2 |
The message signals an error and the payload contains a nlmsgerr structure. | |
#define | NLMSG_DONE 0x3 |
Message terminates a multipart message. | |
#define | NLMSG_OVERRUN 0x4 |
The message signals that data got lost. | |
#define | NLMSG_MIN_TYPE 0x10 |
Lower limit of reserved message types. |
The following information is partly extracted from RFC3549 (ftp://ftp.rfc-editor.org/in-notes/rfc3549.txt)
NLM_F_MULTI
Netlink header flag set, except for the last header which has the Netlink header type NLMSG_DONE
.0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Process ID (PID) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
<------- NLMSG_ALIGN(hlen) ------> <---- NLMSG_ALIGN(len) ---> +----------------------------+- - -+- - - - - - - - - - -+- - -+ | Header | Pad | Payload | Pad | | struct nlmsghdr | | | | +----------------------------+- - -+- - - - - - - - - - -+- - -+
<--- nlmsg_total_size(payload) ---> <-- nlmsg_msg_size(payload) -> +----------+- - -+-------------+- - -+-------- - - | nlmsghdr | Pad | Payload | Pad | nlmsghdr +----------+- - -+-------------+- - -+-------- - - nlmsg_data(nlh)---^ ^ nlmsg_next(nlh)-----------------------+
<---------------------- nlmsg_len(nlh) ---------------------> <------ hdrlen ------> <- nlmsg_attrlen(nlh, hdrlen) -> +----------------------+- - -+--------------------------------+ | Family Header | Pad | Attributes | +----------------------+- - -+--------------------------------+ nlmsg_attrdata(nlh, hdrlen)---^
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Netlink message header | | type = NLMSG_ERROR | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error code | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OLD Netlink message header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// Various methods exist to create/allocate a new netlink // message. // // nlmsg_alloc() will allocate an empty netlink message with // a maximum payload size which defaults to the page size of // the system. This default size can be modified using the // function nlmsg_set_default_size(). struct nl_msg *msg = nlmsg_alloc(); // Very often, the message type and message flags are known // at allocation time while the other fields are auto generated: struct nl_msg *msg = nlmsg_alloc_simple(MY_TYPE, MY_FLAGS); // Alternatively an existing netlink message header can be used // to inherit the header values: struct nlmsghdr hdr = { .nlmsg_type = MY_TYPE, .nlmsg_flags = MY_FLAGS, }; struct nl_msg *msg = nlmsg_inherit(&hdr); // Last but not least, netlink messages received from netlink sockets // can be converted into nl_msg objects using nlmsg_convert(). This // will create a message with a maximum payload size which equals the // length of the existing netlink message, therefore no more data can // be appened without calling nlmsg_expand() first. struct nl_msg *msg = nlmsg_convert(nlh_from_nl_sock); // Payload may be added to the message via nlmsg_append(). The fourth // parameter specifies the number of alignment bytes the data should // be padding with at the end. Common values are 0 to disable it or // NLMSG_ALIGNTO to ensure proper netlink message padding. nlmsg_append(msg, &mydata, sizeof(mydata), 0); // Sometimes it may be necessary to reserve room for data but defer // the actual copying to a later point, nlmsg_reserve() can be used // for this purpose: void *data = nlmsg_reserve(msg, sizeof(mydata), NLMSG_ALIGNTO); // Attributes may be added using the attributes interface. // After successful use of the message, the memory must be freed // using nlmsg_free() nlmsg_free(msg);
int n; unsigned char *buf; struct nlmsghdr *hdr; n = nl_recv(handle, NULL, &buf); hdr = (struct nlmsghdr *) buf; while (nlmsg_ok(hdr, n)) { // Process message here... hdr = nlmsg_next(hdr, &n); }
#define NL_AUTO_PID 0 |
#define NL_AUTO_SEQ 0 |
#define nlmsg_for_each_attr | ( | pos, | |
nlh, | |||
hdrlen, | |||
rem | |||
) |
nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \ nlmsg_attrlen(nlh, hdrlen), rem)
pos | loop counter, set to current attribute |
nlh | netlink message header |
hdrlen | length of family header |
rem | initialized to len, holds bytes currently remaining in stream |
#define nlmsg_for_each_msg | ( | pos, | |
head, | |||
len, | |||
rem | |||
) |
for (pos = head, rem = len; \ nlmsg_ok(pos, rem); \ pos = nlmsg_next(pos, &(rem)))
pos | loop counter, set to current message |
head | head of message stream |
len | length of message stream |
rem | initialized to len, holds bytes currently remaining in stream |
#define NLM_F_ATOMIC 0x400 |
This may require special privileges because it has the potential to interrupt service in the FE for a longer time.
Definition at line 106 of file netlink-kernel.h.
#define NLMSG_ERROR 0x2 |
This can be looked at as a NACK and typically it is from FEC to CPC.
Definition at line 159 of file netlink-kernel.h.
int nlmsg_msg_size | ( | int | payload | ) |
payload | length of message payload |
Definition at line 184 of file msg.c.
Referenced by nl_msg_dump(), nlmsg_padlen(), and nlmsg_total_size().
{
return NLMSG_HDRLEN + payload;
}
int nlmsg_total_size | ( | int | payload | ) |
payload | length of message payload |
Definition at line 193 of file msg.c.
References nlmsg_msg_size().
Referenced by nlmsg_padlen(), and nlmsg_set_default_size().
{ return NLMSG_ALIGN(nlmsg_msg_size(payload)); }
int nlmsg_padlen | ( | int | payload | ) |
payload | length of message payload |
Definition at line 202 of file msg.c.
References nlmsg_msg_size(), and nlmsg_total_size().
{ return nlmsg_total_size(payload) - nlmsg_msg_size(payload); }
void* nlmsg_data | ( | const struct nlmsghdr * | nlh | ) |
nlh | netlink messsage header |
Definition at line 218 of file msg.c.
Referenced by genlmsg_put(), nfnlmsg_family(), nfnlmsg_res_id(), nl_msg_dump(), nla_put(), nla_put_nested(), nla_reserve(), and nlmsg_attrdata().
{ return (unsigned char *) nlh + NLMSG_HDRLEN; }
int nlmsg_len | ( | const struct nlmsghdr * | nlh | ) |
nlh | netlink message header |
Definition at line 232 of file msg.c.
References nlmsghdr::nlmsg_len.
Referenced by nl_msg_dump(), nla_put_nested(), nlmsg_attrlen(), and nlmsg_reserve().
{ return nlh->nlmsg_len - NLMSG_HDRLEN; }
struct nlattr* nlmsg_attrdata | ( | const struct nlmsghdr * | nlh, |
int | hdrlen | ||
) | [read] |
nlh | netlink message header |
hdrlen | length of family specific header |
Definition at line 249 of file msg.c.
References nlmsg_data().
Referenced by nl_msg_dump(), nlmsg_find_attr(), nlmsg_parse(), and nlmsg_validate().
{ unsigned char *data = nlmsg_data(nlh); return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen)); }
int nlmsg_attrlen | ( | const struct nlmsghdr * | nlh, |
int | hdrlen | ||
) |
nlh | netlink message header |
hdrlen | length of family specific header |
Definition at line 260 of file msg.c.
References nlmsg_len().
Referenced by nl_msg_dump(), nlmsg_find_attr(), nlmsg_parse(), and nlmsg_validate().
{ return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen); }
int nlmsg_ok | ( | const struct nlmsghdr * | nlh, |
int | remaining | ||
) |
nlh | netlink message header |
remaining | number of bytes remaining in message stream |
Definition at line 300 of file msg.c.
References nlmsghdr::nlmsg_len.
int nlmsg_parse | ( | struct nlmsghdr * | nlh, |
int | hdrlen, | ||
struct nlattr * | tb[], | ||
int | maxtype, | ||
struct nla_policy * | policy | ||
) |
nlh | netlink message header |
hdrlen | length of family specific header |
tb | destination array with maxtype+1 elements |
maxtype | maximum attribute type to be expected |
policy | validation policy |
See nla_parse()
Definition at line 319 of file msg.c.
References nla_parse(), nlmsg_attrdata(), and nlmsg_attrlen().
{ if (!nlmsg_valid_hdr(nlh, hdrlen)) return nl_errno(EINVAL); return nla_parse(tb, maxtype, nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen), policy); }
struct nlattr* nlmsg_find_attr | ( | struct nlmsghdr * | nlh, |
int | hdrlen, | ||
int | attrtype | ||
) | [read] |
nlh | netlink message header |
hdrlen | length of familiy specific header |
attrtype | type of attribute to look for |
Returns the first attribute which matches the specified type.
Definition at line 337 of file msg.c.
References nla_find(), nlmsg_attrdata(), and nlmsg_attrlen().
{ return nla_find(nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen), attrtype); }
int nlmsg_validate | ( | struct nlmsghdr * | nlh, |
int | hdrlen, | ||
int | maxtype, | ||
struct nla_policy * | policy | ||
) |
nlh | netlinket message header |
hdrlen | length of familiy specific header |
maxtype | maximum attribute type to be expected |
policy | validation policy |
Definition at line 350 of file msg.c.
References nla_validate(), nlmsg_attrdata(), and nlmsg_attrlen().
{ if (!nlmsg_valid_hdr(nlh, hdrlen)) return nl_errno(EINVAL); return nla_validate(nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen), maxtype, policy); }
struct nl_msg* nlmsg_alloc | ( | void | ) | [read] |
Allocates a new netlink message without any further payload. The maximum payload size defaults to PAGESIZE or as otherwise specified with nlmsg_set_default_size().
Definition at line 401 of file msg.c.
Referenced by nlmsg_inherit(), and rtnl_neightbl_build_change_request().
{
return __nlmsg_alloc(default_msg_size);
}
struct nl_msg* nlmsg_inherit | ( | struct nlmsghdr * | hdr | ) | [read] |
hdr | Netlink message header template |
Allocates a new netlink message and inherits the original message header. If hdr is not NULL it will be used as a template for the netlink message header, otherwise the header is left blank.
Definition at line 424 of file msg.c.
References nlmsg_alloc(), nlmsghdr::nlmsg_flags, nlmsghdr::nlmsg_pid, nlmsghdr::nlmsg_seq, and nlmsghdr::nlmsg_type.
Referenced by nl_msg_dump(), and nlmsg_alloc_simple().
{ struct nl_msg *nm; nm = nlmsg_alloc(); if (nm && hdr) { struct nlmsghdr *new = nm->nm_nlh; new->nlmsg_type = hdr->nlmsg_type; new->nlmsg_flags = hdr->nlmsg_flags; new->nlmsg_seq = hdr->nlmsg_seq; new->nlmsg_pid = hdr->nlmsg_pid; } return nm; }
struct nl_msg* nlmsg_alloc_simple | ( | int | nlmsgtype, |
int | flags | ||
) | [read] |
nlmsgtype | Netlink message type |
flags | Message flags. |
Definition at line 448 of file msg.c.
References nlmsg_inherit(), and nlmsghdr::nlmsg_type.
Referenced by flnl_lookup_build_request(), nfnlmsg_alloc_simple(), nl_send_simple(), rtnl_link_build_change_request(), rtnl_neightbl_build_change_request(), and rtnl_qdisc_build_delete_request().
{ struct nl_msg *msg; struct nlmsghdr nlh = { .nlmsg_type = nlmsgtype, .nlmsg_flags = flags, }; msg = nlmsg_inherit(&nlh); if (msg) NL_DBG(2, "msg %p: Allocated new simple message\n", msg); return msg; }
void nlmsg_set_default_size | ( | size_t | max | ) |
max | Size of payload in bytes. |
Definition at line 467 of file msg.c.
References nlmsg_total_size().
{ if (max < nlmsg_total_size(0)) max = nlmsg_total_size(0); default_msg_size = max; }
struct nl_msg* nlmsg_convert | ( | struct nlmsghdr * | hdr | ) | [read] |
hdr | Netlink message received from netlink socket. |
Allocates a new netlink message and copies all of the data pointed to by hdr into the new message object.
Definition at line 484 of file msg.c.
References nlmsg_free(), and nlmsghdr::nlmsg_len.
{ struct nl_msg *nm; nm = __nlmsg_alloc(NLMSG_ALIGN(hdr->nlmsg_len)); if (!nm) goto errout; memcpy(nm->nm_nlh, hdr, hdr->nlmsg_len); return nm; errout: nlmsg_free(nm); return NULL; }
void* nlmsg_reserve | ( | struct nl_msg * | n, |
size_t | len, | ||
int | pad | ||
) |
n | netlink message |
len | length of additional data to reserve room for |
pad | number of bytes to align data to |
Reserves room for additional data at the tail of the an existing netlink message. Eventual padding required will be zeroed out.
Definition at line 512 of file msg.c.
References nlmsg_len().
Referenced by nlmsg_append(), and nlmsg_put().
{ void *buf = n->nm_nlh; size_t nlmsg_len = n->nm_nlh->nlmsg_len; size_t tlen; tlen = pad ? ((len + (pad - 1)) & ~(pad - 1)) : len; if ((tlen + nlmsg_len) > n->nm_size) { nl_errno(ENOBUFS); return NULL; } buf += nlmsg_len; n->nm_nlh->nlmsg_len += tlen; if (tlen > len) memset(buf + len, 0, tlen - len); NL_DBG(2, "msg %p: Reserved %zu bytes, pad=%d, nlmsg_len=%d\n", n, len, pad, n->nm_nlh->nlmsg_len); return buf; }
int nlmsg_append | ( | struct nl_msg * | n, |
void * | data, | ||
size_t | len, | ||
int | pad | ||
) |
n | netlink message |
data | data to add |
len | length of data |
pad | Number of bytes to align data to. |
Extends the netlink message as needed and appends the data of given length to the message.
Definition at line 549 of file msg.c.
References nlmsg_reserve().
Referenced by flnl_lookup_build_request(), nl_send_simple(), rtnl_link_build_change_request(), rtnl_neightbl_build_change_request(), and rtnl_qdisc_build_delete_request().
{ void *tmp; tmp = nlmsg_reserve(n, len, pad); if (tmp == NULL) return nl_errno(ENOMEM); memcpy(tmp, data, len); NL_DBG(2, "msg %p: Appended %zu bytes with padding %d\n", n, len, pad); return 0; }
int nlmsg_expand | ( | struct nl_msg * | n, |
size_t | newlen | ||
) |
n | Netlink message. |
newlen | New maximum payload size. |
Reallocates the payload section of a netlink message and increases the maximum payload size of the message.
Definition at line 577 of file msg.c.
{ void *tmp; if (newlen <= n->nm_size) return nl_errno(EINVAL); tmp = realloc(n->nm_nlh, newlen); if (tmp == NULL) return nl_errno(ENOMEM); n->nm_nlh = tmp; n->nm_size = newlen; return 0; }
struct nlmsghdr* nlmsg_put | ( | struct nl_msg * | n, |
uint32_t | pid, | ||
uint32_t | seq, | ||
int | type, | ||
int | payload, | ||
int | flags | ||
) | [read] |
n | netlink message |
pid | netlink process id or NL_AUTO_PID |
seq | sequence number of message or NL_AUTO_SEQ |
type | message type |
payload | length of message payload |
flags | message flags |
Adds or overwrites the netlink message header in an existing message object. If payload is greater-than zero additional room will be reserved, f.e. for family specific headers. It can be accesed via nlmsg_data().
Definition at line 610 of file msg.c.
References nlmsghdr::nlmsg_flags, nlmsghdr::nlmsg_pid, nlmsg_reserve(), nlmsghdr::nlmsg_seq, and nlmsghdr::nlmsg_type.
Referenced by genlmsg_put(), and nfnlmsg_put().
{ struct nlmsghdr *nlh; if (n->nm_nlh->nlmsg_len < NLMSG_HDRLEN) BUG(); nlh = (struct nlmsghdr *) n->nm_nlh; nlh->nlmsg_type = type; nlh->nlmsg_flags = flags; nlh->nlmsg_pid = pid; nlh->nlmsg_seq = seq; NL_DBG(2, "msg %p: Added netlink header type=%d, flags=%d, pid=%d, " "seq=%d\n", n, type, flags, pid, seq); if (payload > 0 && nlmsg_reserve(n, payload, NLMSG_ALIGNTO) == NULL) return NULL; return nlh; }
struct nlmsghdr* nlmsg_hdr | ( | struct nl_msg * | n | ) | [read] |
n | netlink message |
Returns the actual netlink message casted to the type of the netlink message header.
Definition at line 643 of file msg.c.
Referenced by nl_cache_parse_and_add(), nl_msg_dump(), nl_send_auto_complete(), and nl_sendmsg().
{
return n->nm_nlh;
}
void nlmsg_free | ( | struct nl_msg * | n | ) |
n | netlink message |
Destroys a netlink message and frees up all used memory.
Definition at line 656 of file msg.c.
Referenced by flnl_lookup(), flnl_lookup_build_request(), nfnlmsg_alloc_simple(), nl_msg_dump(), nl_send_simple(), nlmsg_convert(), rtnl_addr_add(), rtnl_addr_delete(), rtnl_class_add(), rtnl_cls_add(), rtnl_cls_change(), rtnl_cls_delete(), rtnl_link_build_change_request(), rtnl_link_change(), rtnl_neigh_add(), rtnl_neigh_change(), rtnl_neigh_delete(), rtnl_neightbl_build_change_request(), rtnl_neightbl_change(), rtnl_qdisc_add(), rtnl_qdisc_change(), rtnl_qdisc_delete(), rtnl_rule_add(), and rtnl_rule_delete().
{ if (!n) return; free(n->nm_nlh); free(n); NL_DBG(2, "msg %p: Freed\n", n); }
void nl_msg_dump | ( | struct nl_msg * | msg, |
FILE * | ofd | ||
) |
msg | Message to print |
ofd | File descriptor. |
Definition at line 947 of file msg.c.
References nlmsgerr::error, nlmsgerr::msg, nl_cache_ops_associate(), nlmsg_attrdata(), nlmsg_attrlen(), nlmsg_data(), nlmsg_free(), nlmsg_hdr(), nlmsg_inherit(), nlmsg_len(), nlmsghdr::nlmsg_len, nlmsg_msg_size(), and nlmsghdr::nlmsg_type.
{ struct nlmsghdr *hdr = nlmsg_hdr(msg); fprintf(ofd, "-------------------------- BEGIN NETLINK MESSAGE " "---------------------------\n"); fprintf(ofd, " [HEADER] %Zu octets\n", sizeof(struct nlmsghdr)); print_hdr(ofd, msg); if (hdr->nlmsg_type == NLMSG_ERROR && hdr->nlmsg_len >= nlmsg_msg_size(sizeof(struct nlmsgerr))) { struct nl_msg *errmsg; struct nlmsgerr *err = nlmsg_data(hdr); fprintf(ofd, " [ERRORMSG] %Zu octets\n", sizeof(*err)); fprintf(ofd, " .error = %d \"%s\"\n", err->error, strerror(-err->error)); fprintf(ofd, " [ORIGINAL MESSAGE] %Zu octets\n", sizeof(*hdr)); errmsg = nlmsg_inherit(&err->msg); print_hdr(ofd, errmsg); nlmsg_free(errmsg); } else if (nlmsg_len(hdr) > 0) { struct nl_cache_ops *ops; int payloadlen = nlmsg_len(hdr); int attrlen = 0; ops = nl_cache_ops_associate(nlmsg_get_proto(msg), hdr->nlmsg_type); if (ops) { attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize); payloadlen -= attrlen; } fprintf(ofd, " [PAYLOAD] %d octets\n", payloadlen); dump_hex(ofd, nlmsg_data(hdr), payloadlen, 0); if (attrlen) { struct nlattr *attrs; int attrlen; attrs = nlmsg_attrdata(hdr, ops->co_hdrsize); attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize); dump_attrs(ofd, attrs, attrlen, 0); } } fprintf(ofd, "--------------------------- END NETLINK MESSAGE " "---------------------------\n"); }