/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2015 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#ifndef NETLINK_H
#define NETLINK_H 1
-/* Netlink interface.
+/* Netlink message helpers.
*
* Netlink is a datagram-based network protocol primarily for communication
* between user processes and the kernel, and mainly on Linux. Netlink is
* specified in RFC 3549, "Linux Netlink as an IP Services Protocol".
*
* Netlink is not suitable for use in physical networks of heterogeneous
- * machines because host byte order is used throughout. */
+ * machines because host byte order is used throughout.
+ *
+ * This header file defines helper functions for working with Netlink messages.
+ * For Netlink protocol definitions, see netlink-protocol.h. For
+ * Linux-specific definitions for Netlink sockets, see netlink-socket.h.
+ */
+#include <netinet/in.h>
#include <stdbool.h>
-#include <sys/uio.h>
+#include <stddef.h>
#include <stdint.h>
+#include "netlink-protocol.h"
+#include "openvswitch/types.h"
struct ofpbuf;
-struct nl_sock;
struct nlattr;
-/* Netlink sockets. */
-
-int nl_sock_create(int protocol, int multicast_group,
- size_t so_sndbuf, size_t so_rcvbuf,
- struct nl_sock **);
-void nl_sock_destroy(struct nl_sock *);
-
-int nl_sock_send(struct nl_sock *, const struct ofpbuf *, bool wait);
-int nl_sock_sendv(struct nl_sock *sock, const struct iovec iov[], size_t n_iov,
- bool wait);
-int nl_sock_recv(struct nl_sock *, struct ofpbuf **, bool wait);
-int nl_sock_transact(struct nl_sock *, const struct ofpbuf *request,
- struct ofpbuf **reply);
-
-void nl_sock_wait(const struct nl_sock *, short int events);
-\f
-/* Netlink messages. */
-
/* Accessing headers and data. */
struct nlmsghdr *nl_msg_nlmsghdr(const struct ofpbuf *);
struct genlmsghdr *nl_msg_genlmsghdr(const struct ofpbuf *);
bool nl_msg_nlmsgerr(const struct ofpbuf *, int *error);
void nl_msg_reserve(struct ofpbuf *, size_t);
-/* Appending headers and raw data. */
-void nl_msg_put_nlmsghdr(struct ofpbuf *, struct nl_sock *,
- size_t expected_payload,
+/* Appending and prepending headers and raw data. */
+void nl_msg_put_nlmsghdr(struct ofpbuf *, size_t expected_payload,
uint32_t type, uint32_t flags);
-void nl_msg_put_genlmsghdr(struct ofpbuf *, struct nl_sock *,
- size_t expected_payload, int family, uint32_t flags,
+void nl_msg_put_genlmsghdr(struct ofpbuf *, size_t expected_payload,
+ int family, uint32_t flags,
uint8_t cmd, uint8_t version);
void nl_msg_put(struct ofpbuf *, const void *, size_t);
void *nl_msg_put_uninit(struct ofpbuf *, size_t);
+void nl_msg_push(struct ofpbuf *, const void *, size_t);
+void *nl_msg_push_uninit(struct ofpbuf *, size_t);
/* Appending attributes. */
void *nl_msg_put_unspec_uninit(struct ofpbuf *, uint16_t type, size_t);
+void *nl_msg_put_unspec_zero(struct ofpbuf *, uint16_t type, size_t);
void nl_msg_put_unspec(struct ofpbuf *, uint16_t type, const void *, size_t);
void nl_msg_put_flag(struct ofpbuf *, uint16_t type);
void nl_msg_put_u8(struct ofpbuf *, uint16_t type, uint8_t value);
void nl_msg_put_u16(struct ofpbuf *, uint16_t type, uint16_t value);
void nl_msg_put_u32(struct ofpbuf *, uint16_t type, uint32_t value);
void nl_msg_put_u64(struct ofpbuf *, uint16_t type, uint64_t value);
+void nl_msg_put_be16(struct ofpbuf *, uint16_t type, ovs_be16 value);
+void nl_msg_put_be32(struct ofpbuf *, uint16_t type, ovs_be32 value);
+void nl_msg_put_be64(struct ofpbuf *, uint16_t type, ovs_be64 value);
+void nl_msg_put_in6_addr(struct ofpbuf *msg, uint16_t type,
+ const struct in6_addr *value);
+void nl_msg_put_odp_port(struct ofpbuf *, uint16_t type, odp_port_t value);
+void nl_msg_put_string__(struct ofpbuf *, uint16_t type, const char *value,
+ size_t len);
void nl_msg_put_string(struct ofpbuf *, uint16_t type, const char *value);
-void nl_msg_put_nested(struct ofpbuf *, uint16_t type, struct ofpbuf *);
+
+size_t nl_msg_start_nested(struct ofpbuf *, uint16_t type);
+void nl_msg_end_nested(struct ofpbuf *, size_t offset);
+void nl_msg_put_nested(struct ofpbuf *, uint16_t type,
+ const void *data, size_t size);
+
+/* Prepending attributes. */
+void *nl_msg_push_unspec_uninit(struct ofpbuf *, uint16_t type, size_t);
+void nl_msg_push_unspec(struct ofpbuf *, uint16_t type, const void *, size_t);
+void nl_msg_push_flag(struct ofpbuf *, uint16_t type);
+void nl_msg_push_u8(struct ofpbuf *, uint16_t type, uint8_t value);
+void nl_msg_push_u16(struct ofpbuf *, uint16_t type, uint16_t value);
+void nl_msg_push_u32(struct ofpbuf *, uint16_t type, uint32_t value);
+void nl_msg_push_u64(struct ofpbuf *, uint16_t type, uint64_t value);
+void nl_msg_push_be16(struct ofpbuf *, uint16_t type, ovs_be16 value);
+void nl_msg_push_be32(struct ofpbuf *, uint16_t type, ovs_be32 value);
+void nl_msg_push_be64(struct ofpbuf *, uint16_t type, ovs_be64 value);
+void nl_msg_push_string(struct ofpbuf *, uint16_t type, const char *value);
+
+/* Separating buffers into individual messages. */
+struct nlmsghdr *nl_msg_next(struct ofpbuf *buffer, struct ofpbuf *msg);
+
+/* Sizes of various attribute types, in bytes, including the attribute header
+ * and padding.
+ *
+ * A minimum-size attribute is 4 bytes long: 4 bytes of header, no bytes of
+ * payload, no padding.
+ *
+ * A maximum-size attribute is 65536 bytes long: 4 bytes of header, 65531 bytes
+ * of payload, 1 byte of padding. (Thus, NL_ATTR_SIZE() of a maximum length
+ * attribute payload does not fit in 16 bits.) */
+#define NL_ATTR_SIZE(PAYLOAD_SIZE) (NLA_HDRLEN + NLA_ALIGN(PAYLOAD_SIZE))
+#define NL_A_U8_SIZE NL_ATTR_SIZE(sizeof(uint8_t))
+#define NL_A_U16_SIZE NL_ATTR_SIZE(sizeof(uint16_t))
+#define NL_A_U32_SIZE NL_ATTR_SIZE(sizeof(uint32_t))
+#define NL_A_U64_SIZE NL_ATTR_SIZE(sizeof(uint64_t))
+#define NL_A_BE16_SIZE NL_ATTR_SIZE(sizeof(ovs_be16))
+#define NL_A_BE32_SIZE NL_ATTR_SIZE(sizeof(ovs_be32))
+#define NL_A_BE64_SIZE NL_ATTR_SIZE(sizeof(ovs_be64))
+#define NL_A_FLAG_SIZE NL_ATTR_SIZE(0)
+#define NL_A_IPV6_SIZE NL_ATTR_SIZE(sizeof(struct in6_addr))
+
+bool nl_attr_oversized(size_t payload_size);
\f
/* Netlink attribute types. */
enum nl_attr_type
NL_A_UNSPEC,
NL_A_U8,
NL_A_U16,
+ NL_A_BE16 = NL_A_U16,
NL_A_U32,
+ NL_A_BE32 = NL_A_U32,
NL_A_U64,
+ NL_A_BE64 = NL_A_U64,
NL_A_STRING,
NL_A_FLAG,
+ NL_A_IPV6,
NL_A_NESTED,
N_NL_ATTR_TYPES
};
+/* Netlink attribute iteration. */
+static inline struct nlattr *
+nl_attr_next(const struct nlattr *nla)
+{
+ return (void *) ((uint8_t *) nla + NLA_ALIGN(nla->nla_len));
+}
+
+static inline bool
+nl_attr_is_valid(const struct nlattr *nla, size_t maxlen)
+{
+ return (maxlen >= sizeof *nla
+ && nla->nla_len >= sizeof *nla
+ && nla->nla_len <= maxlen);
+}
+
+static inline size_t
+nl_attr_len_pad(const struct nlattr *nla, size_t maxlen)
+{
+ size_t len = NLA_ALIGN(nla->nla_len);
+
+ return len <= maxlen ? len : nla->nla_len;
+}
+
+/* This macro is careful to check for attributes with bad lengths. */
+#define NL_ATTR_FOR_EACH(ITER, LEFT, ATTRS, ATTRS_LEN) \
+ for ((ITER) = (ATTRS), (LEFT) = (ATTRS_LEN); \
+ nl_attr_is_valid(ITER, LEFT); \
+ (LEFT) -= nl_attr_len_pad(ITER, LEFT), (ITER) = nl_attr_next(ITER))
+
+
+/* This macro does not check for attributes with bad lengths. It should only
+ * be used with messages from trusted sources or with messages that have
+ * already been validated (e.g. with NL_ATTR_FOR_EACH). */
+#define NL_ATTR_FOR_EACH_UNSAFE(ITER, LEFT, ATTRS, ATTRS_LEN) \
+ for ((ITER) = (ATTRS), (LEFT) = (ATTRS_LEN); \
+ (LEFT) > 0; \
+ (LEFT) -= nl_attr_len_pad(ITER, LEFT), (ITER) = nl_attr_next(ITER))
+
+/* These variants are convenient for iterating nested attributes. */
+#define NL_NESTED_FOR_EACH(ITER, LEFT, A) \
+ NL_ATTR_FOR_EACH(ITER, LEFT, nl_attr_get(A), nl_attr_get_size(A))
+#define NL_NESTED_FOR_EACH_UNSAFE(ITER, LEFT, A) \
+ NL_ATTR_FOR_EACH_UNSAFE(ITER, LEFT, nl_attr_get(A), nl_attr_get_size(A))
+
/* Netlink attribute parsing. */
+int nl_attr_type(const struct nlattr *);
const void *nl_attr_get(const struct nlattr *);
size_t nl_attr_get_size(const struct nlattr *);
const void *nl_attr_get_unspec(const struct nlattr *, size_t size);
uint16_t nl_attr_get_u16(const struct nlattr *);
uint32_t nl_attr_get_u32(const struct nlattr *);
uint64_t nl_attr_get_u64(const struct nlattr *);
+ovs_be16 nl_attr_get_be16(const struct nlattr *);
+ovs_be32 nl_attr_get_be32(const struct nlattr *);
+ovs_be64 nl_attr_get_be64(const struct nlattr *);
+struct in6_addr nl_attr_get_in6_addr(const struct nlattr *nla);
+odp_port_t nl_attr_get_odp_port(const struct nlattr *);
const char *nl_attr_get_string(const struct nlattr *);
+void nl_attr_get_nested(const struct nlattr *, struct ofpbuf *);
/* Netlink attribute policy.
*
bool optional;
};
+#define NL_POLICY_FOR(TYPE) \
+ .type = NL_A_UNSPEC, .min_len = sizeof(TYPE), .max_len = sizeof(TYPE)
+
+bool nl_attr_validate(const struct nlattr *, const struct nl_policy *);
+
bool nl_policy_parse(const struct ofpbuf *, size_t offset,
const struct nl_policy[],
struct nlattr *[], size_t n_attrs);
-\f
-/* Miscellaneous. */
+bool nl_parse_nested(const struct nlattr *, const struct nl_policy[],
+ struct nlattr *[], size_t n_attrs);
-int nl_lookup_genl_family(const char *name, int *number);
+const struct nlattr *nl_attr_find(const struct ofpbuf *, size_t hdr_len,
+ uint16_t type);
+const struct nlattr *nl_attr_find_nested(const struct nlattr *, uint16_t type);
+const struct nlattr *nl_attr_find__(const struct nlattr *attrs, size_t size,
+ uint16_t type);
#endif /* netlink.h */
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