Moyka/OS/uc/tcpip/Source/net_util.c
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/*
*********************************************************************************************************
* uC/TCP-IP
* The Embedded TCP/IP Suite
*
* (c) Copyright 2003-2007; Micrium, Inc.; Weston, FL
*
* All rights reserved. Protected by international copyright laws.
*
* uC/TCP-IP is provided in source form for FREE evaluation, for educational
* use or peaceful research. If you plan on using uC/TCP-IP in a commercial
* product you need to contact Micrium to properly license its use in your
* product. We provide ALL the source code for your convenience and to help
* you experience uC/TCP-IP. The fact that the source code is provided does
* NOT mean that you can use it without paying a licensing fee.
*
* Knowledge of the source code may NOT be used to develop a similar product.
*
* Please help us continue to provide the Embedded community with the finest
* software available. Your honesty is greatly appreciated.
*********************************************************************************************************
*/
/*
*********************************************************************************************************
*
* NETWORK UTILITY LIBRARY
*
* Filename : net_util.c
* Version : V1.89
* Programmer(s) : ITJ
*********************************************************************************************************
* Note(s) : (1) NO compiler-supplied standard library functions are used by the network protocol suite.
* 'net_util.*' implements ALL network-specific library functions.
*
* See also 'net.h NETWORK INCLUDE FILES Note #3'.
*********************************************************************************************************
*/
/*
*********************************************************************************************************
* INCLUDE FILES
*********************************************************************************************************
*/
#define NET_UTIL_MODULE
#include <net.h>
/*$PAGE*/
/*
*********************************************************************************************************
* LOCAL DEFINES
*********************************************************************************************************
*/
#define NET_UTIL_16_BIT_ONES_CPL_NEG_ZERO 0xFFFF
#define NET_UTIL_16_BIT_SUM_ERR_NONE DEF_BIT_NONE
#define NET_UTIL_16_BIT_SUM_ERR_NULL_SIZE DEF_BIT_01
#define NET_UTIL_16_BIT_SUM_ERR_LAST_OCTET DEF_BIT_02
/*
*********************************************************************************************************
* LOCAL CONSTANTS
*********************************************************************************************************
*/
/*
*********************************************************************************************************
* LOCAL DATA TYPES
*********************************************************************************************************
*/
/*
*********************************************************************************************************
* LOCAL TABLES
*********************************************************************************************************
*/
/*
*********************************************************************************************************
* LOCAL GLOBAL VARIABLES
*********************************************************************************************************
*/
/*$PAGE*/
/*
*********************************************************************************************************
* LOCAL FUNCTION PROTOTYPES
*********************************************************************************************************
*/
static CPU_INT32U NetUtil_16BitSumHdrCalc (void *phdr,
CPU_INT16U hdr_size);
static CPU_INT32U NetUtil_16BitSumDataCalc (void *p_data,
CPU_INT16U data_size,
CPU_INT08U *poctet_prev,
CPU_INT08U *poctet_last,
CPU_BOOLEAN prev_octet_valid,
CPU_BOOLEAN last_pkt_buf,
CPU_INT08U *psum_err);
static CPU_INT16U NetUtil_16BitOnesCplSumDataCalc(void *pdata_buf,
void *ppseudo_hdr,
CPU_INT16U pseudo_hdr_size,
NET_ERR *perr);
/*
*********************************************************************************************************
* LOCAL CONFIGURATION ERRORS
*********************************************************************************************************
*/
/*$PAGE*/
/*
*********************************************************************************************************
* NetUtil_16BitOnesCplChkSumHdrCalc()
*
* Description : Calculate 16-bit one's-complement check-sum on packet header.
*
* (1) See RFC #1071, Sections 1, 2.(1), & 4.1 for summary of 16-bit one's-complement
* check-sum & algorithm.
*
* (2) To correctly calculate 16-bit one's-complement check-sums on memory buffers of any
* octet-length & word-alignment, the check-sums MUST be calculated in network-order
* on headers that are arranged in network-order (see also 'NetUtil_16BitSumHdrCalc()
* Note #5b').
*
*
* Argument(s) : phdr Pointer to packet header.
*
* hdr_size Size of packet header.
*
* perr Pointer to variable that will receive the return error code from this function :
*
* NET_UTIL_ERR_NONE Check-sum calculated; check return value.
* NET_UTIL_ERR_NULL_PTR Argument 'phdr' passed a NULL pointer.
* NET_UTIL_ERR_NULL_SIZE Argument 'hdr_size' passed a zero size.
*
* Return(s) : 16-bit one's-complement check-sum, if NO errors.
*
* 0, otherwise.
*
* Caller(s) : various.
*
* This function is an INTERNAL network protocol suite function & SHOULD NOT be called by
* application function(s).
*
* Note(s) : (3) (a) Since the 16-bit sum calculation is returned as a 32-bit network-order value
* (see 'NetUtil_16BitSumHdrCalc() Note #5c1'), ...
*
* (b) ... the final check-sum MUST be converted to host-order but MUST NOT be re-
* converted back to network-order (see 'NetUtil_16BitSumHdrCalc() Note #5c3').
*********************************************************************************************************
*/
NET_CHK_SUM NetUtil_16BitOnesCplChkSumHdrCalc (void *phdr,
CPU_INT16U hdr_size,
NET_ERR *perr)
{
CPU_INT32U sum;
NET_CHK_SUM chk_sum;
NET_CHK_SUM chk_sum_host;
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
/* ------------------ VALIDATE PTR -------------------- */
if (phdr == (void *)0) {
*perr = NET_UTIL_ERR_NULL_PTR;
return (0);
}
/* ------------------ VALIDATE SIZE ------------------- */
if (hdr_size < 1) {
*perr = NET_UTIL_ERR_NULL_SIZE;
return (0);
}
#endif
/* --------- CALC HDR'S 16-BIT ONE'S-CPL SUM ---------- */
sum = NetUtil_16BitSumHdrCalc(phdr, hdr_size); /* Calc 16-bit sum (see Note #3a). */
while (sum >> 16) { /* While 16-bit sum ovf's, ... */
sum = (sum & 0x0000FFFF) + (sum >> 16); /* ... sum ovf bits back into 16-bit one's-cpl sum. */
}
chk_sum = ~((NET_CHK_SUM)sum); /* Perform one's cpl on one's-cpl sum. */
chk_sum_host = NET_UTIL_NET_TO_HOST_16(chk_sum); /* Conv back to host-order (see Note #3b). */
*perr = NET_UTIL_ERR_NONE;
return (chk_sum_host); /* Rtn 16-bit chk sum (see Note #3). */
}
/*$PAGE*/
/*
*********************************************************************************************************
* NetUtil_16BitOnesCplChkSumHdrVerify()
*
* Description : (1) Verify 16-bit one's-complement check-sum on packet header :
*
* (a) Calculate one's-complement sum on packet header
* (b) Verify check-sum by comparison of one's-complement sum to one's-complement
* '-0' value (negative zero)
*
* (2) See RFC #1071, Sections 1, 2.(1), & 4.1 for summary of 16-bit one's-complement
* check-sum & algorithm.
*
* (3) To correctly calculate 16-bit one's-complement check-sums on memory buffers of any
* octet-length & word-alignment, the check-sums MUST be calculated in network-order
* on headers that are arranged in network-order (see also 'NetUtil_16BitSumHdrCalc()
* Note #5b').
*
*
* Argument(s) : phdr Pointer to packet header.
*
* hdr_size Size of packet header.
*
* perr Pointer to variable that will receive the return error code from this function :
*
* NET_UTIL_ERR_NONE Check-sum verified; check return value.
* NET_UTIL_ERR_NULL_PTR Argument 'phdr' passed a NULL pointer.
* NET_UTIL_ERR_NULL_SIZE Argument 'hdr_size' passed a zero size.
*
* Return(s) : DEF_OK, if valid check-sum.
*
* DEF_FAIL, otherwise.
*
* Caller(s) : various.
*
* This function is an INTERNAL network protocol suite function & SHOULD NOT be called by
* application function(s).
*
* Note(s) : (4) (a) Since the 16-bit sum calculation is returned as a 32-bit network-order value
* (see 'NetUtil_16BitSumHdrCalc() Note #5c1'), ...
*
* (b) ... the check-sum MUST be converted to host-order but MUST NOT be re-converted
* back to network-order for the final check-sum comparison
* (see 'NetUtil_16BitSumHdrCalc() Note #5c3').
*********************************************************************************************************
*/
CPU_BOOLEAN NetUtil_16BitOnesCplChkSumHdrVerify (void *phdr,
CPU_INT16U hdr_size,
NET_ERR *perr)
{
CPU_INT32U sum;
NET_CHK_SUM chk_sum;
NET_CHK_SUM chk_sum_host;
CPU_BOOLEAN valid;
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
/* ------------------ VALIDATE PTR -------------------- */
if (phdr == (void *)0) {
*perr = NET_UTIL_ERR_NULL_PTR;
return (DEF_FAIL);
}
/* ------------------ VALIDATE SIZE ------------------- */
if (hdr_size < 1) {
*perr = NET_UTIL_ERR_NULL_SIZE;
return (DEF_FAIL);
}
#endif
/* -------- VERIFY HDR'S 16-BIT ONE'S-CPL SUM --------- */
sum = NetUtil_16BitSumHdrCalc(phdr, hdr_size); /* Calc 16-bit sum (see Note #4a). */
while (sum >> 16) { /* While 16-bit sum ovf's, ... */
sum = (sum & 0x0000FFFF) + (sum >> 16); /* ... sum ovf bits back into 16-bit one's-cpl sum. */
}
chk_sum = (NET_CHK_SUM)sum;
chk_sum_host = NET_UTIL_NET_TO_HOST_16(chk_sum); /* Conv back to host-order (see Note #4b). */
/* Verify chk sum (see Note #1b). */
valid = (chk_sum_host == NET_UTIL_16_BIT_ONES_CPL_NEG_ZERO) ? DEF_OK : DEF_FAIL;
*perr = NET_UTIL_ERR_NONE;
return (valid);
}
/*$PAGE*/
/*
*********************************************************************************************************
* NetUtil_16BitOnesCplChkSumDataCalc()
*
* Description : Calculate 16-bit one's-complement check-sum on packet data.
*
* (1) See RFC #1071, Sections 1, 2.(1), & 4.1 for summary of 16-bit one's-complement
* check-sum & algorithm.
*
* (2) Check-sum calculated on packet data encapsulated in :
*
* (a) One or more network buffers Support non-fragmented & fragmented packets
* (b) Transport layer pseudo-header See RFC #768, Section 'Fields : Checksum' &
* RFC #793, Section 3.1 'Header Format :
* Checksum'.
*
* (3) To correctly calculate 16-bit one's-complement check-sums on memory buffers of any
* octet-length & word-alignment, the check-sums MUST be calculated in network-order on
* data & headers that are arranged in network-order (see also 'NetUtil_16BitSumDataCalc()
* Note #5b').
*
*
* Argument(s) : pdata_buf Pointer to packet data network buffer(s) (see Note #2a).
*
* ppseudo_hdr Pointer to transport layer pseudo-header (see Note #2b).
*
* pseudo_hdr_size Size of transport layer pseudo-header.
*
* perr Pointer to variable that will receive the return error code from this function :
*
* NET_UTIL_ERR_NONE Check-sum calculated; check return value.
*
* - RETURNED BY NetUtil_16BitOnesCplSumDataCalc() : -
* NET_UTIL_ERR_NULL_PTR Argument 'pdata_buf' passed a NULL pointer.
* NET_UTIL_ERR_NULL_SIZE Packet data is a zero size.
* NET_UTIL_ERR_INVALID_PROTOCOL Invalid data packet protocol.
* NET_BUF_ERR_INVALID_IX Invalid buffer index.
*
* Return(s) : 16-bit one's-complement check-sum, if NO errors.
*
* 0, otherwise.
*
* Caller(s) : various.
*
* This function is an INTERNAL network protocol suite function & SHOULD NOT be called by
* application function(s).
*
* Note(s) : (4) (a) Since the 16-bit one's-complement check-sum calculations are returned in host-
* order, ...
*
* (b) ... the returned check-sum MUST NOT be re-converted back to network-order.
*
* See also 'NetUtil_16BitSumDataCalc() Note #5c3' &
* 'NetUtil_16BitOnesCplSumDataCalc() Note #4'.
*********************************************************************************************************
*/
NET_CHK_SUM NetUtil_16BitOnesCplChkSumDataCalc (void *pdata_buf,
void *ppseudo_hdr,
CPU_INT16U pseudo_hdr_size,
NET_ERR *perr)
{
CPU_INT16U sum;
NET_CHK_SUM chk_sum;
/* Calc 16-bit one's-cpl sum (see Note #4a). */
sum = NetUtil_16BitOnesCplSumDataCalc(pdata_buf, ppseudo_hdr, pseudo_hdr_size, perr);
if (*perr != NET_UTIL_ERR_NONE) {
return (0);
}
chk_sum = ~((NET_CHK_SUM)sum); /* Perform one's cpl on one's-cpl sum. */
*perr = NET_UTIL_ERR_NONE;
return (chk_sum); /* Rtn 16-bit chk sum (see Note #4). */
}
/*$PAGE*/
/*
*********************************************************************************************************
* NetUtil_16BitOnesCplChkSumDataVerify()
*
* Description : (1) Verify 16-bit one's-complement check-sum on packet data :
*
* (a) Calculate one's-complement sum on packet data & packet pseudo-header
* (b) Verify check-sum by comparison of one's-complement sum to one's-complement
* '-0' value (negative zero)
*
* (2) See RFC #1071, Sections 1, 2.(1), & 4.1 for summary of 16-bit one's-complement
* check-sum & algorithm.
*
* (3) Check-sum calculated on packet data encapsulated in :
*
* (a) One or more network buffers Support non-fragmented & fragmented packets
* (b) Transport layer pseudo-header See RFC #768, Section 'Fields : Checksum' &
* RFC #793, Section 3.1 'Header Format :
* Checksum'.
*
* (4) To correctly calculate 16-bit one's-complement check-sums on memory buffers of any
* octet-length & word-alignment, the check-sums MUST be calculated in network-order on
* data & headers that are arranged in network-order (see also 'NetUtil_16BitSumDataCalc()
* Note #5b').
*
*
* Argument(s) : pdata_buf Pointer to packet data network buffer(s) (see Note #3a).
*
* ppseudo_hdr Pointer to transport layer pseudo-header (see Note #3b).
*
* pseudo_hdr_size Size of transport layer pseudo-header.
*
* perr Pointer to variable that will receive the return error code from this function :
*
* NET_UTIL_ERR_NONE Check-sum calculated; check return value.
*
* - RETURNED BY NetUtil_16BitOnesCplSumDataCalc() : -
* NET_UTIL_ERR_NULL_PTR Argument 'pdata_buf' passed a NULL pointer.
* NET_UTIL_ERR_NULL_SIZE Packet data is a zero size.
* NET_UTIL_ERR_INVALID_PROTOCOL Invalid data packet protocol.
* NET_BUF_ERR_INVALID_IX Invalid buffer index.
*
* Return(s) : DEF_OK, if valid check-sum.
*
* DEF_FAIL, otherwise.
*
* Caller(s) : various.
*
* This function is an INTERNAL network protocol suite function & SHOULD NOT be called by
* application function(s).
*
* Note(s) : (5) (a) Since the 16-bit one's-complement check-sum calculations are returned in host-
* order, ...
*
* (b) ... the returned check-sum MUST NOT be re-converted back to network-order for
* the final check-sum comparison.
*
* See also 'NetUtil_16BitSumDataCalc() Note #5c3' &
* 'NetUtil_16BitOnesCplSumDataCalc() Note #4'.
*********************************************************************************************************
*/
CPU_BOOLEAN NetUtil_16BitOnesCplChkSumDataVerify (void *pdata_buf,
void *ppseudo_hdr,
CPU_INT16U pseudo_hdr_size,
NET_ERR *perr)
{
CPU_INT16U sum;
NET_CHK_SUM chk_sum;
CPU_BOOLEAN valid;
/* Calc 16-bit one's-cpl sum (see Note #5a). */
sum = NetUtil_16BitOnesCplSumDataCalc(pdata_buf, ppseudo_hdr, pseudo_hdr_size, perr);
if (*perr != NET_UTIL_ERR_NONE) {
return (DEF_FAIL);
}
/* Verify chk sum (see Notes #1b & #5b). */
chk_sum = (NET_CHK_SUM)sum;
valid = (chk_sum == NET_UTIL_16_BIT_ONES_CPL_NEG_ZERO) ? DEF_OK : DEF_FAIL;
*perr = NET_UTIL_ERR_NONE;
return (valid);
}
/*$PAGE*/
/*
*********************************************************************************************************
*********************************************************************************************************
* LOCAL FUNCTIONS
*********************************************************************************************************
*********************************************************************************************************
*/
/*
*********************************************************************************************************
* NetUtil_16BitSumHdrCalc()
*
* Description : Calculate 16-bit sum on packet header memory buffer.
*
* (1) Calculates the sum of consecutive 16-bit values.
*
* (2) 16-bit sum is returned as a 32-bit value to preserve possible 16-bit summation overflow
* in the upper 16-bits.
*
*
* Argument(s) : phdr Pointer to packet header.
* ---- Argument checked in NetUtil_16BitOnesCplChkSumHdrCalc(),
* NetUtil_16BitOnesCplChkSumHdrVerify(),
* NetUtil_16BitOnesCplSumDataCalc().
*
* hdr_size Size of packet header.
*
* Return(s) : 16-bit sum (see Note #2), if NO errors.
*
* 0, otherwise.
*
* Caller(s) : NetUtil_16BitOnesCplChkSumHdrCalc(),
* NetUtil_16BitOnesCplChkSumHdrVerify(),
* NetUtil_16BitOnesCplSumDataCalc().
*
* Note(s) : (3) Since many word-aligned processors REQUIRE that multi-octet words be located on word-
* aligned addresses, 16-bit sum calculation MUST ensure that 16-bit words are accessed
* on addresses that are multiples of 2 octets.
*
* If packet header memory buffer does NOT start on a 16-bit word address boundary, then
* 16-bit sum calculation MUST be performed by concatenating two consecutive 8-bit values.
*
* (4) Modulo arithmetic is used to determine whether a memory buffer starts on the desired
* word-aligned address boundary.
*
* Modulo arithmetic in ANSI-C REQUIREs operations performed on integer values. Thus,
* address values MUST be cast to an appropriately-sized integer value PRIOR to any
* modulo arithmetic operation.
*
* (5) (a) Although "the sum of 16-bit integers can be computed in either byte order"
* [RFC #1071, Section 2.(B)], the handling of odd-length &/or off-word-boundary
* memory buffers is performed assuming network-order.
*
* (b) However, to correctly & consistently calculate 16-bit integer sums for even-/
* odd-length & word-/off-word-boundary memory buffers, the sums MUST be calculated
* in network-order.
*
* (c) (1) To preserve possible 16-bit summation overflow (see Note #2) during all check-
* sum calculations, the 16-bit sum is returned as a 32-bit network-order value.
*
* (2) To encapsulate the network-order transform to the 16-bit check-sum calculations
* ONLY, the final check-sum MUST be converted to host-order.
*
* See 'NetUtil_16BitOnesCplChkSumHdrCalc() Note #3b' &
* 'NetUtil_16BitOnesCplChkSumHdrVerify() Note #4b').
*
* (3) However, since network-to-host-order conversion & host-order memory access are
* inverse operations, the final host-order check-sum value MUST NOT be converted
* back to network-order for calculation or comparison.
*
* (6) RFC #1071, Section 4.1 explicitly casts & sums the last odd-length octet in a check-sum
* calculation as a 16-bit value.
*
* ???? However, this contradicts the following sections which state that "if the total
* length is odd, ... the last octet is padded on the right with ... one octet of zeros
* ... to form a 16 bit word for ... purposes ... [of] computing the checksum" :
*
* (a) RFC #768, Section 'Fields : Checksum'
* (b) RFC #792, Section 'Echo or Echo Reply Message : Checksum'
* (c) RFC #793, Section 3.1 'Header Format : Checksum'
*
* See also 'NetUtil_16BitSumDataCalc() Note #8'.
*********************************************************************************************************
*/
/*$PAGE*/
static CPU_INT32U NetUtil_16BitSumHdrCalc (void *phdr,
CPU_INT16U hdr_size)
{
CPU_INT32U sum_32;
CPU_INT32U sum_val_32;
CPU_INT16U hdr_val_16;
CPU_INT16U size_rem;
CPU_INT16U *phdr_16;
CPU_INT08U *phdr_08;
CPU_INT08U modulo_16;
/* ---------------- VALIDATE SIZE ----------------- */
if (hdr_size < 1) {
return (0);
}
size_rem = hdr_size;
sum_32 = 0;
modulo_16 = (CPU_INT08U)((CPU_ADDR)phdr % sizeof(CPU_INT16U)); /* See Note #4. */
if (modulo_16 == 0) { /* If pkt hdr on 16-bit word boundary (see Note #3),*/
phdr_16 = (CPU_INT16U *)phdr;
while (size_rem >= sizeof(CPU_INT16U)) {
hdr_val_16 = (CPU_INT16U)*phdr_16++;
sum_val_32 = (CPU_INT32U) NET_UTIL_HOST_TO_NET_16(hdr_val_16); /* Conv to net-order (see Note #5b). */
sum_32 += (CPU_INT32U) sum_val_32; /* ... calc sum with 16-bit data words. */
size_rem -= sizeof(CPU_INT16U);
}
phdr_08 = (CPU_INT08U *)phdr_16;
} else { /* Else if pkt hdr NOT on 16-bit word boundary, ... */
phdr_08 = (CPU_INT08U *)phdr;
while (size_rem >= sizeof(CPU_INT16U)) {
sum_val_32 = (CPU_INT32U)*phdr_08++;
sum_val_32 <<= DEF_OCTET_NBR_BITS;
sum_val_32 += (CPU_INT32U)*phdr_08++;
sum_32 += (CPU_INT32U) sum_val_32; /* ... calc sum with 8-bit data vals. */
size_rem -= sizeof(CPU_INT16U);
}
}
if (size_rem > 0) { /* Sum last octet, if any (see Note #6). */
sum_32 += (CPU_INT32U)*phdr_08;
}
return (sum_32); /* Rtn 16-bit sum (see Note #5c1). */
}
/*$PAGE*/
/*
*********************************************************************************************************
* NetUtil_16BitSumDataCalc()
*
* Description : Calculate 16-bit sum on packet data memory buffer.
*
* (1) Calculates the sum of consecutive 16-bit values.
*
* (2) 16-bit sum is returned as a 32-bit value to preserve possible 16-bit summation overflow
* in the upper 16-bits.
*
*
* Argument(s) : p_data Pointer to packet data.
* ------ Argument validated in NetUtil_16BitOnesCplSumDataCalc().
*
* data_size Size of packet data (in this network buffer only
* [see 'NetUtil_16BitOnesCplSumDataCalc() Note #1a']).
*
* poctet_prev Pointer to last octet from a fragmented packet's previous buffer.
* ----------- Argument validated in NetUtil_16BitOnesCplSumDataCalc().
*
* poctet_last Pointer to variable that will receive the value of the last octet from a
* ----------- fragmented packet's current buffer.
*
* Argument validated in NetUtil_16BitOnesCplSumDataCalc().
*
* prev_octet_valid Indicate whether pointer to the last octet of the packet's previous
* ---------------- buffer is valid.
*
* Argument validated in NetUtil_16BitOnesCplSumDataCalc().
*
* last_pkt_buf Indicate whether the current packet buffer is the last packet buffer.
* ------------ Argument validated in NetUtil_16BitOnesCplSumDataCalc().
*
* psum_err Pointer to variable that will receive the error return code(s) from this function :
*
* NET_UTIL_16_BIT_SUM_ERR_NONE No error return codes.
*
* The following error return codes are bit-field codes logically OR'd & MUST
* be individually tested by bit-wise tests :
*
* NET_UTIL_16_BIT_SUM_ERR_NULL_SIZE Packet buffer's data size is
* a zero size.
* NET_UTIL_16_BIT_SUM_ERR_LAST_OCTET Last odd-length octet in packet
* buffer is available; check
* 'poctet_last' return value.
*
* Return(s) : 16-bit sum (see Note #2), if NO errors.
*
* 0, otherwise.
*
* Caller(s) : NetUtil_16BitOnesCplSumDataCalc().
*$PAGE*
* Note(s) : (3) Since many word-aligned processors REQUIRE that multi-octet words be located on word-
* aligned addresses, 16-bit sum calculation MUST ensure that 16-bit words are accessed
* on addresses that are multiples of 2 octets.
*
* If packet data memory buffer does NOT start on a 16-bit word address boundary, then
* 16-bit sum calculation MUST be performed by concatenating two consecutive 8-bit values.
*
* (4) Modulo arithmetic is used to determine whether a memory buffer starts on the desired
* word-aligned address boundary.
*
* Modulo arithmetic in ANSI-C REQUIREs operations performed on integer values. Thus,
* address values MUST be cast to an appropriately-sized integer value PRIOR to any
* modulo arithmetic operation.
*
* (5) (a) Although "the sum of 16-bit integers can be computed in either byte order"
* [RFC #1071, Section 2.(B)], the handling of odd-length &/or off-word-boundary
* memory buffers is performed assuming network-order.
*
* (b) However, to correctly & consistently calculate 16-bit integer sums for even-/
* odd-length & word-/off-word-boundary memory buffers, the sums MUST be calculated
* in network-order so that the last octet of any packet buffer is correctly pre-
* pended to the first octet of the next packet buffer.
*
* (c) (1) To preserve possible 16-bit summation overflow (see Note #2) during all check-
* sum calculations, the 16-bit sum is returned as a 32-bit network-order value.
*
* (2) To encapsulate the network-order transform to the 16-bit check-sum calculations
* ONLY, the final check-sum MUST be converted to host-order
* (see 'NetUtil_16BitOnesCplSumDataCalc() Note #4').
*
* (3) However, since network-to-host-order conversion & host-order memory access are
* inverse operations, the final host-order check-sum value MUST NOT be converted
* back to network-order for calculation or comparison.
*
* (6) Optimized 32-bit sum calculations implemented in the network protocol suite's network-
* specific library port optimization file(s).
*
* See also 'net_util.h FUNCTION PROTOTYPES DEFINED IN PRODUCT'S net_util_a.* Note #1'.
*
* (7) Since pointer arithmetic is based on the specific pointer data type & inherent pointer
* data type size, pointer arithmetic operands :
*
* (a) MUST be in terms of the specific pointer data type & data type size; ...
* (b) SHOULD NOT & in some cases MUST NOT be cast to other data types or data type sizes.
*
* (8) The following sections state that "if the total length is odd, ... the last octet
* is padded on the right with ... one octet of zeros ... to form a 16 bit word for
* ... purposes ... [of] computing the checksum" :
*
* (a) RFC #768, Section 'Fields : Checksum'
* (b) RFC #792, Section 'Echo or Echo Reply Message : Checksum'
* (c) RFC #793, Section 3.1 'Header Format : Checksum'
*
* See also 'NetUtil_16BitSumHdrCalc() Note #6'.
*********************************************************************************************************
*/
/*$PAGE*/
static CPU_INT32U NetUtil_16BitSumDataCalc (void *p_data,
CPU_INT16U data_size,
CPU_INT08U *poctet_prev,
CPU_INT08U *poctet_last,
CPU_BOOLEAN prev_octet_valid,
CPU_BOOLEAN last_pkt_buf,
CPU_INT08U *psum_err)
{
#if (NET_CFG_OPTIMIZE == NET_OPTIMIZE_SPD)
CPU_INT08U modulo_32;
#if ((defined(uC_CFG_OPTIMIZE_ASM_EN)) && \
(uC_CFG_OPTIMIZE_ASM_EN == DEF_ENABLED))
CPU_INT16U size_rem_32_offset;
CPU_INT16U size_rem_32;
#else
CPU_INT32U data_val_32;
CPU_INT32U *pdata_32;
#endif
#endif
CPU_INT32U sum_32;
CPU_INT32U sum_val_32;
CPU_INT16U data_val_16;
CPU_INT16U size_rem;
CPU_INT16U *pdata_16;
CPU_INT08U *pdata_08;
CPU_INT08U modulo_16;
CPU_BOOLEAN pkt_aligned_16;
sum_32 = 0;
if (data_size < 1) { /* ------------ HANDLE NULL-SIZE DATA PKT ------------- */
*psum_err = NET_UTIL_16_BIT_SUM_ERR_NULL_SIZE;
if (prev_octet_valid != DEF_NO) { /* If null size & last octet from prev pkt buf avail .. */
if (last_pkt_buf != DEF_NO) { /* ... & on last pkt buf, ... */
sum_val_32 = (CPU_INT32U)*poctet_prev; /* ... cast prev pkt buf's last octet, ... */
sum_val_32 <<= DEF_OCTET_NBR_BITS; /* ... pad odd-len pkt len (see Note #5) ... */
sum_32 = sum_val_32; /* ... & rtn prev pkt buf's last octet as last sum. */
} else { /* ... & NOT on last pkt buf, ... */
*poctet_last = *poctet_prev; /* ... rtn last octet from prev pkt buf as last octet. */
DEF_BIT_SET(*psum_err, NET_UTIL_16_BIT_SUM_ERR_LAST_OCTET);
}
} else {
; /* If null size & NO prev octet, NO action(s) req'd. */
}
return (sum_32); /* Rtn 16-bit sum (see Note #5c1). */
}
/*$PAGE*/
/* ----------- HANDLE NON-NULL DATA PKT ----------- */
size_rem = data_size;
*psum_err = NET_UTIL_16_BIT_SUM_ERR_NONE;
/* See Notes #3 & #4. */
modulo_16 = (CPU_INT08U)((CPU_ADDR)p_data % sizeof(CPU_INT16U));
pkt_aligned_16 = (((modulo_16 == 0) && (prev_octet_valid == DEF_NO )) ||
((modulo_16 != 0) && (prev_octet_valid == DEF_YES))) ? DEF_YES : DEF_NO;
pdata_08 = (CPU_INT08U *)p_data;
if (prev_octet_valid == DEF_YES) { /* If last octet from prev pkt buf avail, ... */
sum_val_32 = (CPU_INT32U)*poctet_prev;
sum_val_32 <<= DEF_OCTET_NBR_BITS; /* ... prepend last octet from prev pkt buf ... */
sum_val_32 += (CPU_INT32U)*pdata_08++;
sum_32 += (CPU_INT32U) sum_val_32; /* ... to first octet in cur pkt buf. */
size_rem -= sizeof(CPU_INT08U);
}
if (pkt_aligned_16 == DEF_YES) { /* If pkt data aligned on 16-bit boundary, .. */
/* .. calc sum with 16- & 32-bit data words. */
pdata_16 = (CPU_INT16U *)pdata_08;
#if (NET_CFG_OPTIMIZE == NET_OPTIMIZE_SPD)
modulo_32 = (CPU_INT08U )((CPU_ADDR)pdata_16 % sizeof(CPU_INT32U)); /* See Note #4. */
if ((modulo_32 != 0) && /* If leading 16-bit pkt data avail, .. */
(size_rem >= sizeof(CPU_INT16U))) {
data_val_16 = (CPU_INT16U)*pdata_16++;
sum_val_32 = (CPU_INT32U) NET_UTIL_HOST_TO_NET_16(data_val_16); /* Conv to net-order (see Note #5b). */
sum_32 += (CPU_INT32U) sum_val_32; /* .. start calc sum with leading 16-bit data word. */
size_rem -= sizeof(CPU_INT16U);
}
#if ((defined(uC_CFG_OPTIMIZE_ASM_EN)) && \
(uC_CFG_OPTIMIZE_ASM_EN == DEF_ENABLED))
/* Calc optimized 32-bit size rem. */
size_rem_32_offset = (CPU_INT16U)(size_rem % sizeof(CPU_INT32U));
size_rem_32 = (CPU_INT16U)(size_rem - size_rem_32_offset);
/* Calc optimized 32-bit sum (see Note #6). */
sum_val_32 = (CPU_INT32U)NetUtil_16BitSumDataCalcAlign_32((void *)pdata_16,
(CPU_INT32U)size_rem_32);
sum_32 += (CPU_INT32U)sum_val_32;
size_rem -= (CPU_INT32U)size_rem_32;
pdata_08 = (CPU_INT08U *)pdata_16;
pdata_08 += size_rem_32; /* MUST NOT cast ptr operand (see Note #7b). */
pdata_16 = (CPU_INT16U *)pdata_08;
#else
pdata_32 = (CPU_INT32U *)pdata_16;
while (size_rem >= sizeof(CPU_INT32U)) { /* While pkt data aligned on 32-bit boundary; ... */
data_val_32 = (CPU_INT32U) *pdata_32++; /* ... get sum data with 32-bit data words, ... */
data_val_16 = (CPU_INT16U)((data_val_32 >> 16) & 0x0000FFFF);
sum_val_32 = (CPU_INT32U) NET_UTIL_HOST_TO_NET_16(data_val_16); /* Conv to net-order (see Note #5b). */
sum_32 += (CPU_INT32U) sum_val_32; /* ... & calc sum with upper 16-bit data word ... */
data_val_16 = (CPU_INT16U) (data_val_32 & 0x0000FFFF);
sum_val_32 = (CPU_INT32U) NET_UTIL_HOST_TO_NET_16(data_val_16); /* Conv to net-order (see Note #5b). */
sum_32 += (CPU_INT32U) sum_val_32; /* ... & lower 16-bit data word. */
size_rem -= sizeof(CPU_INT32U);
}
pdata_16 = (CPU_INT16U *)pdata_32;
#endif
#endif
while (size_rem >= sizeof(CPU_INT16U)) { /* While pkt data aligned on 16-bit boundary; .. */
data_val_16 = (CPU_INT16U)*pdata_16++;
sum_val_32 = (CPU_INT32U) NET_UTIL_HOST_TO_NET_16(data_val_16); /* Conv to net-order (see Note #5b). */
sum_32 += (CPU_INT32U) sum_val_32; /* .. calc sum with 16-bit data words. */
size_rem -= sizeof(CPU_INT16U);
}
if (size_rem > 0) {
sum_val_32 = (CPU_INT32U)(*((CPU_INT08U *)pdata_16));
}
} else { /* Else pkt data NOT aligned on 16-bit boundary, .. */
while (size_rem >= sizeof(CPU_INT16U)) {
sum_val_32 = (CPU_INT32U)*pdata_08++;
sum_val_32 <<= DEF_OCTET_NBR_BITS;
sum_val_32 += (CPU_INT32U)*pdata_08++;
sum_32 += (CPU_INT32U) sum_val_32; /* .. calc sum with 8-bit data vals. */
size_rem -= sizeof(CPU_INT16U);
}
if (size_rem > 0) {
sum_val_32 = (CPU_INT32U)*pdata_08;
}
}
/*$PAGE*/
if (size_rem > 0) {
if (last_pkt_buf != DEF_NO) { /* If last pkt buf, ... */
sum_val_32 <<= DEF_OCTET_NBR_BITS; /* ... pad odd-len pkt len (see Note #8). */
sum_32 += (CPU_INT32U)sum_val_32;
} else {
*poctet_last = (CPU_INT08U)sum_val_32; /* Else rtn last octet. */
DEF_BIT_SET(*psum_err, NET_UTIL_16_BIT_SUM_ERR_LAST_OCTET);
}
}
return (sum_32); /* Rtn 16-bit sum (see Note #5c1). */
}
/*$PAGE*/
/*
*********************************************************************************************************
* NetUtil_16BitOnesCplSumDataCalc()
*
* Description : Calculate 16-bit one's-complement sum on packet data.
*
* (1) Calculates the 16-bit one's-complement sum of packet data encapsulated in :
*
* (a) One or more network buffers Support non-fragmented & fragmented packets
* (b) Transport layer pseudo-header See RFC #768, Section 'Fields : Checksum' &
* RFC #793, Section 3.1 'Header Format :
* Checksum'.
*
* Argument(s) : pdata_buf Pointer to packet data network buffer(s) (see Notes #1a & #2).
*
* ppseudo_hdr Pointer to transport layer pseudo-header (see Note #1b).
*
* pseudo_hdr_size Size of transport layer pseudo-header.
*
* perr Pointer to variable that will receive the return error code from this function :
*
* NET_UTIL_ERR_NONE 16-bit one's-complement sum calculated;
* check return value.
* NET_UTIL_ERR_NULL_PTR Argument 'pdata_buf' passed a NULL pointer.
* NET_UTIL_ERR_NULL_SIZE Packet data is a zero size.
* NET_UTIL_ERR_INVALID_PROTOCOL Invalid data packet protocol.
* NET_BUF_ERR_INVALID_IX Invalid buffer index.
*
* Return(s) : 16-bit one's-complement sum, if NO errors.
*
* 0, otherwise.
*
* Caller(s) : NetUtil_16BitOnesCplChkSumDataCalc(),
* NetUtil_16BitOnesCplChkSumDataVerify().
*
* Note(s) : (2) Pointer to network buffer packet NOT validated as a network buffer. However, no memory
* corruption occurs since no write operations are performed.
*
* (3) Default case already invalidated in earlier functions. However, the default case is
* included as an extra precaution in case 'ProtocolHdrType' is incorrectly modified.
*
* (4) (a) Since the 16-bit sum calculations are returned as 32-bit network-order values
* (see 'NetUtil_16BitSumDataCalc() Note #5c1'), ...
*
* (b) ... the one's-complement sum MUST be converted to host-order but MUST NOT be re-
* converted back to network-order (see 'NetUtil_16BitSumDataCalc() Note #5c3').
*********************************************************************************************************
*/
/*$PAGE*/
static CPU_INT16U NetUtil_16BitOnesCplSumDataCalc (void *pdata_buf,
void *ppseudo_hdr,
CPU_INT16U pseudo_hdr_size,
NET_ERR *perr)
{
NET_BUF *pbuf;
NET_BUF *pbuf_next;
NET_BUF_HDR *pbuf_hdr;
void *p_data;
CPU_INT32U sum;
CPU_INT32U sum_val;
CPU_INT16U sum_ones_cpl;
CPU_INT16U sum_ones_cpl_host;
CPU_INT16U data_ix;
CPU_INT16U data_len;
CPU_INT08U sum_err;
CPU_INT08U octet_prev;
CPU_INT08U octet_last;
CPU_BOOLEAN octet_prev_valid;
CPU_BOOLEAN octet_last_valid;
CPU_BOOLEAN mem_buf_last;
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
CPU_BOOLEAN mem_buf_first;
CPU_BOOLEAN mem_buf_null_size;
#endif
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED) /* ----------------- VALIDATE PTR ----------------- */
if (pdata_buf == (void *)0) {
*perr = NET_UTIL_ERR_NULL_PTR;
return (0);
}
#endif
/* ------ CALC PKT DATA 16-BIT ONE'S-CPL SUM ------ */
pbuf = (NET_BUF *)pdata_buf;
sum = 0;
octet_prev = 0;
octet_last = 0;
octet_prev_valid = DEF_NO;
octet_last_valid = DEF_NO;
mem_buf_last = DEF_NO;
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
mem_buf_first = DEF_YES;
#endif
if (ppseudo_hdr != (void *)0) { /* Calc pkt's pseudo-hdr 16-bit sum (see Note #1b). */
sum_val = NetUtil_16BitSumDataCalc((void *) ppseudo_hdr,
(CPU_INT16U ) pseudo_hdr_size,
(CPU_INT08U *)&octet_prev,
(CPU_INT08U *)&octet_last,
(CPU_BOOLEAN ) octet_prev_valid,
(CPU_BOOLEAN ) mem_buf_last,
(CPU_INT08U *)&sum_err);
sum += sum_val;
octet_last_valid = DEF_BIT_IS_SET(sum_err, NET_UTIL_16_BIT_SUM_ERR_LAST_OCTET);
if (octet_last_valid == DEF_YES) { /* If last octet from pseudo-hdr avail, ... */
octet_prev = octet_last; /* ... prepend last octet to first pkt buf. */
octet_prev_valid = DEF_YES;
} else {
octet_prev = 0;
octet_prev_valid = DEF_NO;
}
}
/*$PAGE*/
while (pbuf != (NET_BUF *)0) { /* Calc ALL data pkts' 16-bit sum (see Note #1a). */
pbuf_hdr = &pbuf->Hdr;
switch (pbuf_hdr->ProtocolHdrType) { /* Demux pkt buf's protocol ix & len. */
case NET_PROTOCOL_TYPE_ICMP:
data_ix = pbuf_hdr->ICMP_MsgIx;
data_len = pbuf_hdr->ICMP_HdrLen + (CPU_INT16U)pbuf_hdr->DataLen;
break;
case NET_PROTOCOL_TYPE_UDP:
case NET_PROTOCOL_TYPE_TCP:
data_ix = pbuf_hdr->TCP_UDP_HdrDataIx;
data_len = pbuf_hdr->TCP_UDP_HdrLen + (CPU_INT16U)pbuf_hdr->DataLen;
break;
default: /* See Note #3. */
*perr = NET_UTIL_ERR_INVALID_PROTOCOL;
return (0); /* Prevent 'break NOT reachable' compiler warning. */
}
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
if (data_ix == NET_BUF_IX_NONE) {
*perr = NET_BUF_ERR_INVALID_IX;
return (0);
}
#endif
p_data = (void *)&pbuf->Data[data_ix];
pbuf_next = (NET_BUF *) pbuf_hdr->NextBufPtr;
mem_buf_last = (pbuf_next == (NET_BUF *)0) ? DEF_YES : DEF_NO;
/* Calc pkt buf's 16-bit sum. */
sum_val = NetUtil_16BitSumDataCalc((void *) p_data,
(CPU_INT16U ) data_len,
(CPU_INT08U *)&octet_prev,
(CPU_INT08U *)&octet_last,
(CPU_BOOLEAN ) octet_prev_valid,
(CPU_BOOLEAN ) mem_buf_last,
(CPU_INT08U *)&sum_err);
#if (NET_ERR_CFG_ARG_CHK_DBG_EN == DEF_ENABLED)
if (mem_buf_first == DEF_YES) {
mem_buf_first = DEF_NO;
if (mem_buf_last == DEF_YES) {
mem_buf_null_size = DEF_BIT_IS_SET(sum_err, NET_UTIL_16_BIT_SUM_ERR_NULL_SIZE);
if (mem_buf_null_size != DEF_NO) { /* If ONLY mem buf & null size, rtn err. */
*perr = NET_UTIL_ERR_NULL_SIZE;
return (0);
}
}
}
#endif
if (mem_buf_last != DEF_YES) { /* If NOT on last pkt buf & ... */
octet_last_valid = DEF_BIT_IS_SET(sum_err, NET_UTIL_16_BIT_SUM_ERR_LAST_OCTET);
if (octet_last_valid == DEF_YES) { /* ... last octet from cur pkt buf avail, */
octet_prev = octet_last; /* ... prepend last octet to next pkt buf. */
octet_prev_valid = DEF_YES;
} else {
octet_prev = 0;
octet_prev_valid = DEF_NO;
}
}
sum += sum_val;
pbuf = pbuf_next;
}
while (sum >> 16) { /* While 16-bit sum ovf's, ... */
sum = (sum & 0x0000FFFF) + (sum >> 16); /* ... sum ovf bits back into 16-bit one's-cpl sum. */
}
sum_ones_cpl = (CPU_INT16U)sum;
sum_ones_cpl_host = NET_UTIL_NET_TO_HOST_16(sum_ones_cpl); /* Conv back to host-order (see Note #4b). */
*perr = NET_UTIL_ERR_NONE;
return (sum_ones_cpl_host); /* Rtn 16-bit one's-cpl sum (see Note #1). */
}