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The functions in the architecture specific module implement the IP check sum and 32-bit additions. More...
Files | |
file | uip_arch.h |
Declarations of architecture specific functions. | |
Functions | |
void | uip_add32 (uint8_t *op32, uint16_t op16) |
Carry out a 32-bit addition. | |
uint16_t | uip_chksum (uint16_t *buf, uint16_t len) |
Calculate the Internet checksum over a buffer. | |
uint16_t | uip_ipchksum (void) |
Calculate the IP header checksum of the packet header in uip_buf. | |
uint16_t | uip_tcpchksum (void) |
Calculate the TCP checksum of the packet in uip_buf and uip_appdata. | |
Variables | |
uint8_t | uip_acc32 [4] |
4-byte array used for the 32-bit sequence number calculations. |
The functions in the architecture specific module implement the IP check sum and 32-bit additions.
The IP checksum calculation is the most computationally expensive operation in the TCP/IP stack and it therefore pays off to implement this in efficient assembler. The purpose of the uip-arch module is to let the checksum functions to be implemented in architecture specific assembler.
void uip_add32 | ( | uint8_t * | op32, |
uint16_t | op16 | ||
) |
Carry out a 32-bit addition.
Because not all architectures for which uIP is intended has native 32-bit arithmetic, uIP uses an external C function for doing the required 32-bit additions in the TCP protocol processing. This function should add the two arguments and place the result in the global variable uip_acc32.
op32 | A pointer to a 4-byte array representing a 32-bit integer in network byte order (big endian). |
op16 | A 16-bit integer in host byte order. |
Definition at line 241 of file uip.c.
References uip_acc32.
Referenced by uip_process(), and uip_split_output().
uint16_t uip_chksum | ( | uint16_t * | buf, |
uint16_t | len | ||
) |
Calculate the Internet checksum over a buffer.
The Internet checksum is the one's complement of the one's complement sum of all 16-bit words in the buffer.
See RFC1071.
buf | A pointer to the buffer over which the checksum is to be computed. |
len | The length of the buffer over which the checksum is to be computed. |
The Internet checksum is the one's complement of the one's complement sum of all 16-bit words in the buffer.
See RFC1071.
buf | A pointer to the buffer over which the checksum is to be computed. |
len | The length of the buffer over which the checksum is to be computed. |
Definition at line 303 of file uip.c.
References uip_htons().
Referenced by uip_process().
uint16_t uip_ipchksum | ( | void | ) |
Calculate the IP header checksum of the packet header in uip_buf.
The IP header checksum is the Internet checksum of the 20 bytes of the IP header.
Definition at line 310 of file uip.c.
References uip_htons(), uip_ipchksum(), and UIP_LLH_LEN.
Referenced by hc_inflate(), uip_ipchksum(), uip_process(), and uip_split_output().
uint16_t uip_tcpchksum | ( | void | ) |
Calculate the TCP checksum of the packet in uip_buf and uip_appdata.
The TCP checksum is the Internet checksum of data contents of the TCP segment, and a pseudo-header as defined in RFC793.
The TCP checksum is the Internet checksum of data contents of the TCP segment, and a pseudo-header as defined in RFC793.
Definition at line 356 of file uip.c.
References uip_appdata, UIP_LLH_LEN, and uip_tcpchksum().
Referenced by uip_process(), uip_split_output(), and uip_tcpchksum().