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aosp12/external/libpcap/extract.h

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/*
* Copyright (c) 1992, 1993, 1994, 1995, 1996
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef _WIN32
#include <arpa/inet.h>
#endif
#include <pcap/pcap-inttypes.h>
#include <pcap/compiler-tests.h>
#include "portability.h"
/*
* If we have versions of GCC or Clang that support an __attribute__
* to say "if we're building with unsigned behavior sanitization,
* don't complain about undefined behavior in this function", we
* label these functions with that attribute - we *know* it's undefined
* in the C standard, but we *also* know it does what we want with
* the ISA we're targeting and the compiler we're using.
*
* For GCC 4.9.0 and later, we use __attribute__((no_sanitize_undefined));
* pre-5.0 GCC doesn't have __has_attribute, and I'm not sure whether
* GCC or Clang first had __attribute__((no_sanitize(XXX)).
*
* For Clang, we check for __attribute__((no_sanitize(XXX)) with
* __has_attribute, as there are versions of Clang that support
* __attribute__((no_sanitize("undefined")) but don't support
* __attribute__((no_sanitize_undefined)).
*
* We define this here, rather than in funcattrs.h, because we
* only want it used here, we don't want it to be broadly used.
* (Any printer will get this defined, but this should at least
* make it harder for people to find.)
*/
#if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 409)
#define UNALIGNED_OK __attribute__((no_sanitize_undefined))
#elif __has_attribute(no_sanitize)
#define UNALIGNED_OK __attribute__((no_sanitize("undefined")))
#else
#define UNALIGNED_OK
#endif
#if (defined(__i386__) || defined(_M_IX86) || defined(__X86__) || defined(__x86_64__) || defined(_M_X64)) || \
(defined(__m68k__) && (!defined(__mc68000__) && !defined(__mc68010__))) || \
(defined(__ppc__) || defined(__ppc64__) || defined(_M_PPC) || defined(_ARCH_PPC) || defined(_ARCH_PPC64)) || \
(defined(__s390__) || defined(__s390x__) || defined(__zarch__))
/*
* The processor natively handles unaligned loads, so we can just
* cast the pointer and fetch through it.
*
* XXX - are those all the x86 tests we need?
* XXX - are those the only 68k tests we need not to generated
* unaligned accesses if the target is the 68000 or 68010?
* XXX - are there any tests we don't need, because some definitions are for
* compilers that also predefine the GCC symbols?
* XXX - do we need to test for both 32-bit and 64-bit versions of those
* architectures in all cases?
*/
UNALIGNED_OK static inline uint16_t
EXTRACT_BE_U_2(const void *p)
{
return ((uint16_t)ntohs(*(const uint16_t *)(p)));
}
UNALIGNED_OK static inline int16_t
EXTRACT_BE_S_2(const void *p)
{
return ((int16_t)ntohs(*(const int16_t *)(p)));
}
UNALIGNED_OK static inline uint32_t
EXTRACT_BE_U_4(const void *p)
{
return ((uint32_t)ntohl(*(const uint32_t *)(p)));
}
UNALIGNED_OK static inline int32_t
EXTRACT_BE_S_4(const void *p)
{
return ((int32_t)ntohl(*(const int32_t *)(p)));
}
UNALIGNED_OK static inline uint64_t
EXTRACT_BE_U_8(const void *p)
{
return ((uint64_t)(((uint64_t)ntohl(*((const uint32_t *)(p) + 0))) << 32 |
((uint64_t)ntohl(*((const uint32_t *)(p) + 1))) << 0));
}
UNALIGNED_OK static inline int64_t
EXTRACT_BE_S_8(const void *p)
{
return ((int64_t)(((int64_t)ntohl(*((const uint32_t *)(p) + 0))) << 32 |
((uint64_t)ntohl(*((const uint32_t *)(p) + 1))) << 0));
}
#elif PCAP_IS_AT_LEAST_GNUC_VERSION(2,0) && \
(defined(__alpha) || defined(__alpha__) || \
defined(__mips) || defined(__mips__))
/*
* This is MIPS or Alpha, which don't natively handle unaligned loads,
* but which have instructions that can help when doing unaligned
* loads, and this is GCC 2.0 or later or a compiler that claims to
* be GCC 2.0 or later, which we assume that mean we have
* __attribute__((packed)), which we can use to convince the compiler
* to generate those instructions.
*
* Declare packed structures containing a uint16_t and a uint32_t,
* cast the pointer to point to one of those, and fetch through it;
* the GCC manual doesn't appear to explicitly say that
* __attribute__((packed)) causes the compiler to generate unaligned-safe
* code, but it apppears to do so.
*
* We do this in case the compiler can generate code using those
* instructions to do an unaligned load and pass stuff to "ntohs()" or
* "ntohl()", which might be better than the code to fetch the
* bytes one at a time and assemble them. (That might not be the
* case on a little-endian platform, such as DEC's MIPS machines and
* Alpha machines, where "ntohs()" and "ntohl()" might not be done
* inline.)
*
* We do this only for specific architectures because, for example,
* at least some versions of GCC, when compiling for 64-bit SPARC,
* generate code that assumes alignment if we do this.
*
* XXX - add other architectures and compilers as possible and
* appropriate.
*
* HP's C compiler, indicated by __HP_cc being defined, supports
* "#pragma unaligned N" in version A.05.50 and later, where "N"
* specifies a number of bytes at which the typedef on the next
* line is aligned, e.g.
*
* #pragma unalign 1
* typedef uint16_t unaligned_uint16_t;
*
* to define unaligned_uint16_t as a 16-bit unaligned data type.
* This could be presumably used, in sufficiently recent versions of
* the compiler, with macros similar to those below. This would be
* useful only if that compiler could generate better code for PA-RISC
* or Itanium than would be generated by a bunch of shifts-and-ORs.
*
* DEC C, indicated by __DECC being defined, has, at least on Alpha,
* an __unaligned qualifier that can be applied to pointers to get the
* compiler to generate code that does unaligned loads and stores when
* dereferencing the pointer in question.
*
* XXX - what if the native C compiler doesn't support
* __attribute__((packed))? How can we get it to generate unaligned
* accesses for *specific* items?
*/
typedef struct {
uint16_t val;
} __attribute__((packed)) unaligned_uint16_t;
typedef struct {
int16_t val;
} __attribute__((packed)) unaligned_int16_t;
typedef struct {
uint32_t val;
} __attribute__((packed)) unaligned_uint32_t;
typedef struct {
int32_t val;
} __attribute__((packed)) unaligned_int32_t;
UNALIGNED_OK static inline uint16_t
EXTRACT_BE_U_2(const void *p)
{
return ((uint16_t)ntohs(((const unaligned_uint16_t *)(p))->val));
}
UNALIGNED_OK static inline int16_t
EXTRACT_BE_S_2(const void *p)
{
return ((int16_t)ntohs(((const unaligned_int16_t *)(p))->val));
}
UNALIGNED_OK static inline uint32_t
EXTRACT_BE_U_4(const void *p)
{
return ((uint32_t)ntohl(((const unaligned_uint32_t *)(p))->val));
}
UNALIGNED_OK static inline int32_t
EXTRACT_BE_S_4(const void *p)
{
return ((int32_t)ntohl(((const unaligned_int32_t *)(p))->val));
}
UNALIGNED_OK static inline uint64_t
EXTRACT_BE_U_8(const void *p)
{
return ((uint64_t)(((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 0)->val)) << 32 |
((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 1)->val)) << 0));
}
UNALIGNED_OK static inline int64_t
EXTRACT_BE_S_8(const void *p)
{
return ((int64_t)(((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 0)->val)) << 32 |
((uint64_t)ntohl(((const unaligned_uint32_t *)(p) + 1)->val)) << 0));
}
#else
/*
* This architecture doesn't natively support unaligned loads, and either
* this isn't a GCC-compatible compiler, we don't have __attribute__,
* or we do but we don't know of any better way with this instruction
* set to do unaligned loads, so do unaligned loads of big-endian
* quantities the hard way - fetch the bytes one at a time and
* assemble them.
*
* XXX - ARM is a special case. ARMv1 through ARMv5 didn't suppory
* unaligned loads; ARMv6 and later support it *but* have a bit in
* the system control register that the OS can set and that causes
* unaligned loads to fault rather than succeeding.
*
* At least some OSes may set that flag, so we do *not* treat ARM
* as supporting unaligned loads. If your OS supports them on ARM,
* and you want to use them, please update the tests in the #if above
* to check for ARM *and* for your OS.
*/
#define EXTRACT_BE_U_2(p) \
((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
#define EXTRACT_BE_S_2(p) \
((int16_t)(((uint16_t)(*((const uint8_t *)(p) + 0)) << 8) | \
((uint16_t)(*((const uint8_t *)(p) + 1)) << 0)))
#define EXTRACT_BE_U_4(p) \
((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
#define EXTRACT_BE_S_4(p) \
((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
#define EXTRACT_BE_U_8(p) \
((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
#define EXTRACT_BE_S_8(p) \
((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 56) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 7)) << 0)))
/*
* Extract an IPv4 address, which is in network byte order, and not
* necessarily aligned, and provide the result in host byte order.
*/
#define EXTRACT_IPV4_TO_HOST_ORDER(p) \
((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 24) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 3)) << 0)))
#endif /* unaligned access checks */
/*
* Non-power-of-2 sizes.
*/
#define EXTRACT_BE_U_3(p) \
((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 0)))
#define EXTRACT_BE_S_3(p) \
(((*((const uint8_t *)(p) + 0)) & 0x80) ? \
((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 0))) : \
((int32_t)(0xFF000000U | \
((uint32_t)(*((const uint8_t *)(p) + 0)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 0))))
#define EXTRACT_BE_U_5(p) \
((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 0)))
#define EXTRACT_BE_S_5(p) \
(((*((const uint8_t *)(p) + 0)) & 0x80) ? \
((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 0))) : \
((int64_t)(INT64_T_CONSTANT(0xFFFFFF0000000000U) | \
((uint64_t)(*((const uint8_t *)(p) + 0)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 0))))
#define EXTRACT_BE_U_6(p) \
((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 0)))
#define EXTRACT_BE_S_6(p) \
(((*((const uint8_t *)(p) + 0)) & 0x80) ? \
((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 0))) : \
((int64_t)(INT64_T_CONSTANT(0xFFFFFFFF00000000U) | \
((uint64_t)(*((const uint8_t *)(p) + 0)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 0))))
#define EXTRACT_BE_U_7(p) \
((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 0)))
#define EXTRACT_BE_S_7(p) \
(((*((const uint8_t *)(p) + 0)) & 0x80) ? \
((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 0))) : \
((int64_t)(INT64_T_CONSTANT(0xFFFFFFFFFF000000U) | \
((uint64_t)(*((const uint8_t *)(p) + 0)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 0))))
/*
* Macros to extract possibly-unaligned little-endian integral values.
* XXX - do loads on little-endian machines that support unaligned loads?
*/
#define EXTRACT_LE_U_2(p) \
((uint16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_S_2(p) \
((int16_t)(((uint16_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint16_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_U_4(p) \
((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_S_4(p) \
((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_U_3(p) \
((uint32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_S_3(p) \
((int32_t)(((uint32_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint32_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint32_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_U_8(p) \
((uint64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
#define EXTRACT_LE_S_8(p) \
((int64_t)(((uint64_t)(*((const uint8_t *)(p) + 7)) << 56) | \
((uint64_t)(*((const uint8_t *)(p) + 6)) << 48) | \
((uint64_t)(*((const uint8_t *)(p) + 5)) << 40) | \
((uint64_t)(*((const uint8_t *)(p) + 4)) << 32) | \
((uint64_t)(*((const uint8_t *)(p) + 3)) << 24) | \
((uint64_t)(*((const uint8_t *)(p) + 2)) << 16) | \
((uint64_t)(*((const uint8_t *)(p) + 1)) << 8) | \
((uint64_t)(*((const uint8_t *)(p) + 0)) << 0)))
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