LWIP 2.1.2 移植ST ping 不通

ST默认配置了硬件检查校验和（lwipopt.h），lwip 默认了软件检查校验和，在opt.h中#define CHECKSUM_GEN_ICMP                  1 表示软件检查，在opt.h中#define CHECKSUM_GEN_ICMP                  0//1改为为0，或者在lwipopt.h中加上#define CHECKSUM_GEN_ICMP                  0 

 

#define CHECKSUM_BY_HARDWARE 

#ifdef CHECKSUM_BY_HARDWARE
  /* CHECKSUM_GEN_IP==0: Generate checksums by hardware for outgoing IP packets.*/
  #define CHECKSUM_GEN_IP                 0
  /* CHECKSUM_GEN_UDP==0: Generate checksums by hardware for outgoing UDP packets.*/
  #define CHECKSUM_GEN_UDP                0
  /* CHECKSUM_GEN_TCP==0: Generate checksums by hardware for outgoing TCP packets.*/
  #define CHECKSUM_GEN_TCP                0

/* CHECKSUM_GEN_ICMP==0: Generate checksums by hardware for outgoing ICMP packets.*/
  #define CHECKSUM_GEN_ICMP                  0 
  /* CHECKSUM_CHECK_IP==0: Check checksums by hardware for incoming IP packets.*/
  #define CHECKSUM_CHECK_IP               0
  /* CHECKSUM_CHECK_UDP==0: Check checksums by hardware for incoming UDP packets.*/
  #define CHECKSUM_CHECK_UDP              0
  /* CHECKSUM_CHECK_TCP==0: Check checksums by hardware for incoming TCP packets.*/
  #define CHECKSUM_CHECK_TCP              0
#else
  /* CHECKSUM_GEN_IP==1: Generate checksums in software for outgoing IP packets.*/
  #define CHECKSUM_GEN_IP                 1
  /* CHECKSUM_GEN_UDP==1: Generate checksums in software for outgoing UDP packets.*/
  #define CHECKSUM_GEN_UDP                1
  /* CHECKSUM_GEN_TCP==1: Generate checksums in software for outgoing TCP packets.*/
  #define CHECKSUM_GEN_TCP                1
  /* CHECKSUM_CHECK_IP==1: Check checksums in software for incoming IP packets.*/
  #define CHECKSUM_CHECK_IP               1
  /* CHECKSUM_CHECK_UDP==1: Check checksums in software for incoming UDP packets.*/
  #define CHECKSUM_CHECK_UDP              1
  /* CHECKSUM_CHECK_TCP==1: Check checksums in software for incoming TCP packets.*/
  #define CHECKSUM_CHECK_TCP              1
#endif