haproxy/include/common/net_helper.h

372 lines
12 KiB
C

/*
* include/common/net_helper.h
* This file contains miscellaneous network helper functions.
*
* Copyright (C) 2017 Olivier Houchard
* Copyright (C) 2017 Willy Tarreau
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _COMMON_NET_HELPER_H
#define _COMMON_NET_HELPER_H
#include <common/compiler.h>
#include <common/standard.h>
#include <arpa/inet.h>
/* Functions to read/write various integers that may be unaligned */
/* Read a uint16_t in native host order */
static inline uint16_t read_u16(const void *p)
{
const union { uint16_t u16; } __attribute__((packed))*u = p;
return u->u16;
}
/* Write a uint16_t in native host order */
static inline void write_u16(void *p, const uint16_t u16)
{
union { uint16_t u16; } __attribute__((packed))*u = p;
u->u16 = u16;
}
/* Read a uint32_t in native host order */
static inline uint32_t read_u32(const void *p)
{
const union { uint32_t u32; } __attribute__((packed))*u = p;
return u->u32;
}
/* Write a uint32_t in native host order */
static inline void write_u32(void *p, const uint32_t u32)
{
union { uint32_t u32; } __attribute__((packed))*u = p;
u->u32 = u32;
}
/* Read a uint64_t in native host order */
static inline uint64_t read_u64(const void *p)
{
const union { uint64_t u64; } __attribute__((packed))*u = p;
return u->u64;
}
/* Write a uint64_t in native host order */
static inline void write_u64(void *p, const uint64_t u64)
{
union { uint64_t u64; } __attribute__((packed))*u = p;
u->u64 = u64;
}
/* Read a possibly wrapping number of bytes <bytes> into destination <dst>. The
* first segment is composed of <s1> bytes at p1. The remaining byte(s), if any,
* are read from <p2>. <s1> may be zero and may also be larger than <bytes>. The
* caller is always responsible for providing enough bytes. Note: the function
* is purposely *not* marked inline to let the compiler decide what to do with
* it, because it's around 34 bytes long, placed on critical path but rarely
* called, and uses uses a lot of arguments if not inlined. The compiler will
* thus decide what's best to do with it depending on the context.
*/
static void readv_bytes(void *dst, const size_t bytes, const void *p1, size_t s1, const void *p2)
{
size_t idx;
p2 -= s1;
for (idx = 0; idx < bytes; idx++) {
if (idx == s1)
p1 = p2;
((uint8_t *)dst)[idx] = ((const uint8_t *)p1)[idx];
}
/* this memory barrier is critical otherwise gcc may over-optimize this
* code, completely removing it as well as any surrounding boundary
* check (4.7.1..6.4.0)!
*/
__asm__ volatile("" ::: "memory");
}
/* Write a possibly wrapping number of bytes <bytes> from location <src>. The
* first segment is composed of <s1> bytes at p1. The remaining byte(s), if any,
* are written to <p2>. <s1> may be zero and may also be larger than <bytes>.
* The caller is always responsible for providing enough room. Note: the
* function is purposely *not* marked inline to let the compiler decide what to
* do with it, because it's around 34 bytes long, placed on critical path but
* rarely called, and uses uses a lot of arguments if not inlined. The compiler
* will thus decide what's best to do with it depending on the context.
*/
static void writev_bytes(const void *src, const size_t bytes, void *p1, size_t s1, void *p2)
{
size_t idx;
p2 -= s1;
for (idx = 0; idx < bytes; idx++) {
if (idx == s1)
p1 = p2;
((uint8_t *)p1)[idx] = ((const uint8_t *)src)[idx];
}
}
/* Read a possibly wrapping uint16_t in native host order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are read from
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough bytes.
*/
static inline uint16_t readv_u16(const void *p1, size_t s1, const void *p2)
{
if (unlikely(s1 == 1)) {
volatile uint16_t u16;
((uint8_t *)&u16)[0] = *(uint8_t *)p1;
((uint8_t *)&u16)[1] = *(uint8_t *)p2;
return u16;
}
else {
const union { uint16_t u16; } __attribute__((packed)) *u;
u = (s1 == 0) ? p2 : p1;
return u->u16;
}
}
/* Write a possibly wrapping uint16_t in native host order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are written to
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough room.
*/
static inline void writev_u16(void *p1, size_t s1, void *p2, const uint16_t u16)
{
union { uint16_t u16; } __attribute__((packed)) *u;
if (unlikely(s1 == 1)) {
*(uint8_t *)p1 = ((const uint8_t *)&u16)[0];
*(uint8_t *)p2 = ((const uint8_t *)&u16)[1];
}
else {
u = (s1 == 0) ? p2 : p1;
u->u16 = u16;
}
}
/* Read a possibly wrapping uint32_t in native host order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are read from
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough bytes.
*/
static inline uint32_t readv_u32(const void *p1, size_t s1, const void *p2)
{
uint32_t u32;
if (!unlikely(s1 < sizeof(u32)))
u32 = read_u32(p1);
else
readv_bytes(&u32, sizeof(u32), p1, s1, p2);
return u32;
}
/* Write a possibly wrapping uint32_t in native host order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are written to
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough room.
*/
static inline void writev_u32(void *p1, size_t s1, void *p2, const uint32_t u32)
{
if (!unlikely(s1 < sizeof(u32)))
write_u32(p1, u32);
else
writev_bytes(&u32, sizeof(u32), p1, s1, p2);
}
/* Read a possibly wrapping uint64_t in native host order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are read from
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough bytes.
*/
static inline uint64_t readv_u64(const void *p1, size_t s1, const void *p2)
{
uint64_t u64;
if (!unlikely(s1 < sizeof(u64)))
u64 = read_u64(p1);
else
readv_bytes(&u64, sizeof(u64), p1, s1, p2);
return u64;
}
/* Write a possibly wrapping uint64_t in native host order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are written to
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough room.
*/
static inline void writev_u64(void *p1, size_t s1, void *p2, const uint64_t u64)
{
if (!unlikely(s1 < sizeof(u64)))
write_u64(p1, u64);
else
writev_bytes(&u64, sizeof(u64), p1, s1, p2);
}
/* Signed integer versions : return the same data but signed */
/* Read an int16_t in native host order */
static inline int16_t read_i16(const void *p)
{
return read_u16(p);
}
/* Read an int32_t in native host order */
static inline int32_t read_i32(const void *p)
{
return read_u32(p);
}
/* Read an int64_t in native host order */
static inline int64_t read_i64(const void *p)
{
return read_u64(p);
}
/* Read a possibly wrapping int16_t in native host order */
static inline int16_t readv_i16(const void *p1, size_t s1, const void *p2)
{
return readv_u16(p1, s1, p2);
}
/* Read a possibly wrapping int32_t in native host order */
static inline int32_t readv_i32(const void *p1, size_t s1, const void *p2)
{
return readv_u32(p1, s1, p2);
}
/* Read a possibly wrapping int64_t in native host order */
static inline int64_t readv_i64(const void *p1, size_t s1, const void *p2)
{
return readv_u64(p1, s1, p2);
}
/* Read a uint16_t, and convert from network order to host order */
static inline uint16_t read_n16(const void *p)
{
return ntohs(read_u16(p));
}
/* Write a uint16_t after converting it from host order to network order */
static inline void write_n16(void *p, const uint16_t u16)
{
write_u16(p, htons(u16));
}
/* Read a uint32_t, and convert from network order to host order */
static inline uint32_t read_n32(const void *p)
{
return ntohl(read_u32(p));
}
/* Write a uint32_t after converting it from host order to network order */
static inline void write_n32(void *p, const uint32_t u32)
{
write_u32(p, htonl(u32));
}
/* Read a uint64_t, and convert from network order to host order */
static inline uint64_t read_n64(const void *p)
{
return my_ntohll(read_u64(p));
}
/* Write a uint64_t after converting it from host order to network order */
static inline void write_n64(void *p, const uint64_t u64)
{
write_u64(p, my_htonll(u64));
}
/* Read a possibly wrapping uint16_t in network order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are read from
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough bytes.
*/
static inline uint16_t readv_n16(const void *p1, size_t s1, const void *p2)
{
if (unlikely(s1 < 2)) {
if (s1 == 0)
p1 = p2++;
}
else
p2 = p1 + 1;
return (*(uint8_t *)p1 << 8) + *(uint8_t *)p2;
}
/* Write a possibly wrapping uint16_t in network order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are written to
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough room.
*/
static inline void writev_n16(const void *p1, size_t s1, const void *p2, const uint16_t u16)
{
if (unlikely(s1 < 2)) {
if (s1 == 0)
p1 = p2++;
}
else
p2 = p1 + 1;
*(uint8_t *)p1 = u16 >> 8;
*(uint8_t *)p2 = u16;
}
/* Read a possibly wrapping uint32_t in network order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are read from
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough bytes.
*/
static inline uint32_t readv_n32(const void *p1, size_t s1, const void *p2)
{
return ntohl(readv_u32(p1, s1, p2));
}
/* Write a possibly wrapping uint32_t in network order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are written to
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough room.
*/
static inline void writev_n32(void *p1, size_t s1, void *p2, const uint32_t u32)
{
writev_u32(p1, s1, p2, htonl(u32));
}
/* Read a possibly wrapping uint64_t in network order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are read from
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough bytes.
*/
static inline uint64_t readv_n64(const void *p1, size_t s1, const void *p2)
{
return my_ntohll(readv_u64(p1, s1, p2));
}
/* Write a possibly wrapping uint64_t in network order. The first segment is
* composed of <s1> bytes at p1. The remaining byte(s), if any, are written to
* <p2>. <s1> may be zero and may be larger than the type. The caller is always
* responsible for providing enough room.
*/
static inline void writev_n64(void *p1, size_t s1, void *p2, const uint64_t u64)
{
writev_u64(p1, s1, p2, my_htonll(u64));
}
#endif /* COMMON_NET_HELPER_H */