/*
- * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "netlink.h"
-#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <sys/types.h>
#include "netlink-protocol.h"
#include "ofpbuf.h"
#include "timeval.h"
+#include "unaligned.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(netlink);
ofpbuf_prealloc_tailroom(msg, NLMSG_ALIGN(size));
}
-static uint32_t
-get_nlmsg_seq(void)
-{
- /* Next nlmsghdr sequence number.
- *
- * This implementation uses sequence numbers that are unique process-wide,
- * to avoid a hypothetical race: send request, close socket, open new
- * socket that reuses the old socket's PID value, send request on new
- * socket, receive reply from kernel to old socket but with same PID and
- * sequence number. (This race could be avoided other ways, e.g. by
- * preventing PIDs from being quickly reused). */
- static uint32_t next_seq;
-
- if (next_seq == 0) {
- /* Pick initial sequence number. */
- next_seq = getpid() ^ time_wall();
- }
- return next_seq++;
-}
-
/* Puts a nlmsghdr at the beginning of 'msg', which must be initially empty.
* Uses the given 'type' and 'flags'. 'expected_payload' should be
* an estimate of the number of payload bytes to be supplied; if the size of
* is often NLM_F_REQUEST indicating that a request is being made, commonly
* or'd with NLM_F_ACK to request an acknowledgement.
*
- * Sets the new nlmsghdr's nlmsg_pid field to 0 for now. nl_sock_send() will
- * fill it in just before sending the message.
+ * Sets the new nlmsghdr's nlmsg_len, nlmsg_seq, and nlmsg_pid fields to 0 for
+ * now. Functions that send Netlink messages will fill these in just before
+ * sending the message.
*
* nl_msg_put_genlmsghdr() is more convenient for composing a Generic Netlink
* message. */
{
struct nlmsghdr *nlmsghdr;
- assert(msg->size == 0);
+ ovs_assert(msg->size == 0);
nl_msg_reserve(msg, NLMSG_HDRLEN + expected_payload);
nlmsghdr = nl_msg_put_uninit(msg, NLMSG_HDRLEN);
nlmsghdr->nlmsg_len = 0;
nlmsghdr->nlmsg_type = type;
nlmsghdr->nlmsg_flags = flags;
- nlmsghdr->nlmsg_seq = get_nlmsg_seq();
+ nlmsghdr->nlmsg_seq = 0;
nlmsghdr->nlmsg_pid = 0;
}
struct genlmsghdr *genlmsghdr;
nl_msg_put_nlmsghdr(msg, GENL_HDRLEN + expected_payload, family, flags);
- assert(msg->size == NLMSG_HDRLEN);
+ ovs_assert(msg->size == NLMSG_HDRLEN);
genlmsghdr = nl_msg_put_uninit(msg, GENL_HDRLEN);
genlmsghdr->cmd = cmd;
genlmsghdr->version = version;
return p;
}
+/* Prepends the 'size' bytes of data in 'p', plus Netlink padding if needed, to
+ * the head end of 'msg'. Data in 'msg' is reallocated and copied if
+ * necessary. */
+void
+nl_msg_push(struct ofpbuf *msg, const void *data, size_t size)
+{
+ memcpy(nl_msg_push_uninit(msg, size), data, size);
+}
+
+/* Prepends 'size' bytes of data, plus Netlink padding if needed, to the head
+ * end of 'msg', reallocating and copying its data if necessary. Returns a
+ * pointer to the first byte of the new data, which is left uninitialized. */
+void *
+nl_msg_push_uninit(struct ofpbuf *msg, size_t size)
+{
+ size_t pad = NLMSG_ALIGN(size) - size;
+ char *p = ofpbuf_push_uninit(msg, size + pad);
+ if (pad) {
+ memset(p + size, 0, pad);
+ }
+ return p;
+}
+
/* Appends a Netlink attribute of the given 'type' and room for 'size' bytes of
* data as its payload, plus Netlink padding if needed, to the tail end of
* 'msg', reallocating and copying its data if necessary. Returns a pointer to
{
size_t total_size = NLA_HDRLEN + size;
struct nlattr* nla = nl_msg_put_uninit(msg, total_size);
- assert(NLA_ALIGN(total_size) <= UINT16_MAX);
+ ovs_assert(NLA_ALIGN(total_size) <= UINT16_MAX);
nla->nla_len = total_size;
nla->nla_type = type;
return nla + 1;
nl_msg_put_unspec(msg, type, value, strlen(value) + 1);
}
+/* Prepends a Netlink attribute of the given 'type' and room for 'size' bytes
+ * of data as its payload, plus Netlink padding if needed, to the head end of
+ * 'msg', reallocating and copying its data if necessary. Returns a pointer to
+ * the first byte of data in the attribute, which is left uninitialized. */
+void *
+nl_msg_push_unspec_uninit(struct ofpbuf *msg, uint16_t type, size_t size)
+{
+ size_t total_size = NLA_HDRLEN + size;
+ struct nlattr* nla = nl_msg_push_uninit(msg, total_size);
+ ovs_assert(NLA_ALIGN(total_size) <= UINT16_MAX);
+ nla->nla_len = total_size;
+ nla->nla_type = type;
+ return nla + 1;
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the 'size' bytes of
+ * 'data' as its payload, to the head end of 'msg', reallocating and copying
+ * its data if necessary. Returns a pointer to the first byte of data in the
+ * attribute, which is left uninitialized. */
+void
+nl_msg_push_unspec(struct ofpbuf *msg, uint16_t type,
+ const void *data, size_t size)
+{
+ memcpy(nl_msg_push_unspec_uninit(msg, type, size), data, size);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and no payload to 'msg'.
+ * (Some Netlink protocols use the presence or absence of an attribute as a
+ * Boolean flag.) */
+void
+nl_msg_push_flag(struct ofpbuf *msg, uint16_t type)
+{
+ nl_msg_push_unspec(msg, type, NULL, 0);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 8-bit 'value'
+ * to 'msg'. */
+void
+nl_msg_push_u8(struct ofpbuf *msg, uint16_t type, uint8_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 16-bit host
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_push_u16(struct ofpbuf *msg, uint16_t type, uint16_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 32-bit host
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_push_u32(struct ofpbuf *msg, uint16_t type, uint32_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 64-bit host
+ * byte order 'value' to 'msg'. */
+void
+nl_msg_push_u64(struct ofpbuf *msg, uint16_t type, uint64_t value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 16-bit
+ * network byte order 'value' to 'msg'. */
+void
+nl_msg_push_be16(struct ofpbuf *msg, uint16_t type, ovs_be16 value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 32-bit
+ * network byte order 'value' to 'msg'. */
+void
+nl_msg_push_be32(struct ofpbuf *msg, uint16_t type, ovs_be32 value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given 64-bit
+ * network byte order 'value' to 'msg'. */
+void
+nl_msg_push_be64(struct ofpbuf *msg, uint16_t type, ovs_be64 value)
+{
+ nl_msg_push_unspec(msg, type, &value, sizeof value);
+}
+
+/* Prepends a Netlink attribute of the given 'type' and the given
+ * null-terminated string 'value' to 'msg'. */
+void
+nl_msg_push_string(struct ofpbuf *msg, uint16_t type, const char *value)
+{
+ nl_msg_push_unspec(msg, type, value, strlen(value) + 1);
+}
+
/* Adds the header for nested Netlink attributes to 'msg', with the specified
* 'type', and returns the header's offset within 'msg'. The caller should add
* the content for the nested Netlink attribute to 'msg' (e.g. using the other
const void *
nl_attr_get(const struct nlattr *nla)
{
- assert(nla->nla_len >= NLA_HDRLEN);
+ ovs_assert(nla->nla_len >= NLA_HDRLEN);
return nla + 1;
}
size_t
nl_attr_get_size(const struct nlattr *nla)
{
- assert(nla->nla_len >= NLA_HDRLEN);
+ ovs_assert(nla->nla_len >= NLA_HDRLEN);
return nla->nla_len - NLA_HDRLEN;
}
const void *
nl_attr_get_unspec(const struct nlattr *nla, size_t size)
{
- assert(nla->nla_len >= NLA_HDRLEN + size);
+ ovs_assert(nla->nla_len >= NLA_HDRLEN + size);
return nla + 1;
}
uint64_t
nl_attr_get_u64(const struct nlattr *nla)
{
- return NL_ATTR_GET_AS(nla, uint64_t);
+ const ovs_32aligned_u64 *x = nl_attr_get_unspec(nla, sizeof *x);
+ return get_32aligned_u64(x);
}
/* Returns the 16-bit network byte order value in 'nla''s payload.
ovs_be64
nl_attr_get_be64(const struct nlattr *nla)
{
- return NL_ATTR_GET_AS(nla, ovs_be64);
+ const ovs_32aligned_be64 *x = nl_attr_get_unspec(nla, sizeof *x);
+ return get_32aligned_be64(x);
}
/* Returns the null-terminated string value in 'nla''s payload.
const char *
nl_attr_get_string(const struct nlattr *nla)
{
- assert(nla->nla_len > NLA_HDRLEN);
- assert(memchr(nl_attr_get(nla), '\0', nla->nla_len - NLA_HDRLEN) != NULL);
+ ovs_assert(nla->nla_len > NLA_HDRLEN);
+ ovs_assert(memchr(nl_attr_get(nla), '\0', nla->nla_len - NLA_HDRLEN));
return nl_attr_get(nla);
}
[NL_A_NESTED] = { 0, SIZE_MAX },
};
+bool
+nl_attr_validate(const struct nlattr *nla, const struct nl_policy *policy)
+{
+ uint16_t type = nl_attr_type(nla);
+ size_t min_len;
+ size_t max_len;
+ size_t len;
+
+ if (policy->type == NL_A_NO_ATTR) {
+ return true;
+ }
+
+ /* Figure out min and max length. */
+ min_len = policy->min_len;
+ if (!min_len) {
+ min_len = attr_len_range[policy->type][0];
+ }
+ max_len = policy->max_len;
+ if (!max_len) {
+ max_len = attr_len_range[policy->type][1];
+ }
+
+ /* Verify length. */
+ len = nl_attr_get_size(nla);
+ if (len < min_len || len > max_len) {
+ VLOG_DBG_RL(&rl, "attr %"PRIu16" length %zu not in "
+ "allowed range %zu...%zu", type, len, min_len, max_len);
+ return false;
+ }
+
+ /* Strings must be null terminated and must not have embedded nulls. */
+ if (policy->type == NL_A_STRING) {
+ if (((char *) nla)[nla->nla_len - 1]) {
+ VLOG_DBG_RL(&rl, "attr %"PRIu16" lacks null at end", type);
+ return false;
+ }
+ if (memchr(nla + 1, '\0', len - 1) != NULL) {
+ VLOG_DBG_RL(&rl, "attr %"PRIu16" has bad length", type);
+ return false;
+ }
+ }
+
+ return true;
+}
+
/* Parses the 'msg' starting at the given 'nla_offset' as a sequence of Netlink
* attributes. 'policy[i]', for 0 <= i < n_attrs, specifies how the attribute
* with nla_type == i is parsed; a pointer to attribute i is stored in
const struct nl_policy policy[],
struct nlattr *attrs[], size_t n_attrs)
{
- void *p, *tail;
- size_t n_required;
+ struct nlattr *nla;
+ size_t left;
size_t i;
- n_required = 0;
- for (i = 0; i < n_attrs; i++) {
- attrs[i] = NULL;
-
- assert(policy[i].type < N_NL_ATTR_TYPES);
- if (policy[i].type != NL_A_NO_ATTR
- && policy[i].type != NL_A_FLAG
- && !policy[i].optional) {
- n_required++;
- }
- }
+ memset(attrs, 0, n_attrs * sizeof *attrs);
- p = ofpbuf_at(msg, nla_offset, 0);
- if (p == NULL) {
+ if (msg->size < nla_offset) {
VLOG_DBG_RL(&rl, "missing headers in nl_policy_parse");
return false;
}
- tail = ofpbuf_tail(msg);
-
- while (p < tail) {
- size_t offset = (char*)p - (char*)msg->data;
- struct nlattr *nla = p;
- size_t len, aligned_len;
- uint16_t type;
-
- /* Make sure its claimed length is plausible. */
- if (nla->nla_len < NLA_HDRLEN) {
- VLOG_DBG_RL(&rl, "%zu: attr shorter than NLA_HDRLEN (%"PRIu16")",
- offset, nla->nla_len);
- return false;
- }
- len = nla->nla_len - NLA_HDRLEN;
- aligned_len = NLA_ALIGN(len);
- if (aligned_len > (char*)tail - (char*)p) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" aligned data len (%zu) "
- "> bytes left (%tu)",
- offset, nl_attr_type(nla), aligned_len,
- (char*)tail - (char*)p);
- return false;
- }
- type = nl_attr_type(nla);
+ NL_ATTR_FOR_EACH (nla, left,
+ (struct nlattr *) ((char *) msg->data + nla_offset),
+ msg->size - nla_offset)
+ {
+ uint16_t type = nl_attr_type(nla);
if (type < n_attrs && policy[type].type != NL_A_NO_ATTR) {
const struct nl_policy *e = &policy[type];
- size_t min_len, max_len;
-
- /* Validate length and content. */
- min_len = e->min_len ? e->min_len : attr_len_range[e->type][0];
- max_len = e->max_len ? e->max_len : attr_len_range[e->type][1];
- if (len < min_len || len > max_len) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" length %zu not in "
- "allowed range %zu...%zu",
- offset, type, len, min_len, max_len);
+ if (!nl_attr_validate(nla, e)) {
return false;
}
- if (e->type == NL_A_STRING) {
- if (((char *) nla)[nla->nla_len - 1]) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" lacks null at end",
- offset, type);
- return false;
- }
- if (memchr(nla + 1, '\0', len - 1) != NULL) {
- VLOG_DBG_RL(&rl, "%zu: attr %"PRIu16" has bad length",
- offset, type);
- return false;
- }
- }
- if (!e->optional && attrs[type] == NULL) {
- assert(n_required > 0);
- --n_required;
- }
if (attrs[type]) {
- VLOG_DBG_RL(&rl, "%zu: duplicate attr %"PRIu16, offset, type);
+ VLOG_DBG_RL(&rl, "duplicate attr %"PRIu16, type);
}
attrs[type] = nla;
- } else {
- /* Skip attribute type that we don't care about. */
}
- p = (char*)p + NLA_ALIGN(nla->nla_len);
}
- if (n_required) {
- VLOG_DBG_RL(&rl, "%zu required attrs missing", n_required);
+ if (left) {
+ VLOG_DBG_RL(&rl, "attributes followed by garbage");
return false;
}
+
+ for (i = 0; i < n_attrs; i++) {
+ const struct nl_policy *e = &policy[i];
+ if (!e->optional && e->type != NL_A_NO_ATTR && !attrs[i]) {
+ VLOG_DBG_RL(&rl, "required attr %zu missing", i);
+ return false;
+ }
+ }
return true;
}
return nl_policy_parse(&buf, 0, policy, attrs, n_attrs);
}
-static const struct nlattr *
+const struct nlattr *
nl_attr_find__(const struct nlattr *attrs, size_t size, uint16_t type)
{
const struct nlattr *nla;
size_t left;
NL_ATTR_FOR_EACH (nla, left, attrs, size) {
- if (nl_attr_type (nla) == type) {
+ if (nl_attr_type(nla) == type) {
return nla;
}
}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff