如何解决'struct tcphdr' has no member named 'th_seq'？

wangdan1600

想从pppd source中单独编译vjcompress.c
[root@dwang tcpcommpress]# cc -c vjcompress.c -o vjcompress.o
vjcompress.c: In function 'vj_compress_init':
vjcompress.c:76: warning: incompatible implicit declaration of built-in function 'bzero'
vjcompress.c: In function 'vj_compress_tcp':
vjcompress.c:173: error: 'struct tcphdr' has no member named 'th_flags'
vjcompress.c:173: error: 'TH_SYN' undeclared (first use in this function)
vjcompress.c:173: error: (Each undeclared identifier is reported only once
vjcompress.c:173: error: for each function it appears in.)
vjcompress.c:173: error: 'TH_FIN' undeclared (first use in this function)
vjcompress.c:173: error: 'TH_RST' undeclared (first use in this function)
vjcompress.c:173: error: 'TH_ACK' undeclared (first use in this function)
vjcompress.c:220: error: 'struct tcphdr' has no member named 'th_off'
vjcompress.c:252: error: 'struct tcphdr' has no member named 'th_off'
vjcompress.c:260: error: 'struct tcphdr' has no member named 'th_off'
.....

这个文件中使用了
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
这些文件都存在的,且PATH环境变量也设置了/usr/include：
[root@dwang tcpcommpress]# cd /usr/include/netinet/
ether.h     if_ether.h  if_tr.h     in.h        ip6.h       ip_icmp.h   udp.h      
icmp6.h     if_fddi.h   igmp.h      in_systm.h  ip.h        tcp.h  

tcp.h中tcphdr定义如下：

56  # ifdef __FAVOR_BSD &nbsp;&nbsp;&nbsp;&nbsp;57  typedef u_int32_t tcp_seq; &nbsp;&nbsp;&nbsp;&nbsp;58  /* &nbsp;&nbsp;&nbsp;&nbsp;59   * TCP header. &nbsp;&nbsp;&nbsp;&nbsp;60   * Per RFC 793, September, 1981. &nbsp;&nbsp;&nbsp;&nbsp;61   */ &nbsp;&nbsp;&nbsp;&nbsp;62  struct tcphdr &nbsp;&nbsp;&nbsp;&nbsp;63    { &nbsp;&nbsp;&nbsp;&nbsp;64      u_int16_t th_sport;         /* source port */ &nbsp;&nbsp;&nbsp;&nbsp;65      u_int16_t th_dport;         /* destination port */ &nbsp;&nbsp;&nbsp;&nbsp;66      tcp_seq th_seq;             /* sequence number */ &nbsp;&nbsp;&nbsp;&nbsp;67      tcp_seq th_ack;             /* acknowledgement number */ &nbsp;&nbsp;&nbsp;&nbsp;68  #  if __BYTE_ORDER == __LITTLE_ENDIAN &nbsp;&nbsp;&nbsp;&nbsp;69      u_int8_t th_x2:4;           /* (unused) */ &nbsp;&nbsp;&nbsp;&nbsp;70      u_int8_t th_off:4;          /* data offset */ &nbsp;&nbsp;&nbsp;&nbsp;71  #  endif &nbsp;&nbsp;&nbsp;&nbsp;72  #  if __BYTE_ORDER == __BIG_ENDIAN &nbsp;&nbsp;&nbsp;&nbsp;73      u_int8_t th_off:4;          /* data offset */ &nbsp;&nbsp;&nbsp;&nbsp;74      u_int8_t th_x2:4;           /* (unused) */ &nbsp;&nbsp;&nbsp;&nbsp;75  #  endif &nbsp;&nbsp;&nbsp;&nbsp;76      u_int8_t th_flags; &nbsp;&nbsp;&nbsp;&nbsp;77  #  define TH_FIN        0x01 &nbsp;&nbsp;&nbsp;&nbsp;78  #  define TH_SYN        0x02 &nbsp;&nbsp;&nbsp;&nbsp;79  #  define TH_RST        0x04 &nbsp;&nbsp;&nbsp;&nbsp;80  #  define TH_PUSH       0x08 &nbsp;&nbsp;&nbsp;&nbsp;81  #  define TH_ACK        0x10 &nbsp;&nbsp;&nbsp;&nbsp;82  #  define TH_URG        0x20 &nbsp;&nbsp;&nbsp;&nbsp;83      u_int16_t th_win;           /* window */ &nbsp;&nbsp;&nbsp;&nbsp;84      u_int16_t th_sum;           /* checksum */ &nbsp;&nbsp;&nbsp;&nbsp;85      u_int16_t th_urp;           /* urgent pointer */ &nbsp;&nbsp;&nbsp;&nbsp;86  }; &nbsp;&nbsp;&nbsp;&nbsp;87 &nbsp;&nbsp;&nbsp;&nbsp;88  # else /* !__FAVOR_BSD */ &nbsp;&nbsp;&nbsp;&nbsp;89  struct tcphdr &nbsp;&nbsp;&nbsp;&nbsp;90    { &nbsp;&nbsp;&nbsp;&nbsp;91      u_int16_t source; &nbsp;&nbsp;&nbsp;&nbsp;92      u_int16_t dest; &nbsp;&nbsp;&nbsp;&nbsp;93      u_int32_t seq; &nbsp;&nbsp;&nbsp;&nbsp;94      u_int32_t ack_seq; &nbsp;&nbsp;&nbsp;&nbsp;95  #  if __BYTE_ORDER == __LITTLE_ENDIAN &nbsp;&nbsp;&nbsp;&nbsp;96      u_int16_t res1:4; &nbsp;&nbsp;&nbsp;&nbsp;97      u_int16_t doff:4; &nbsp;&nbsp;&nbsp;&nbsp;98      u_int16_t fin:1; &nbsp;&nbsp;&nbsp;&nbsp;99      u_int16_t syn:1; &nbsp;&nbsp;&nbsp;100      u_int16_t rst:1; &nbsp;&nbsp;&nbsp;101      u_int16_t psh:1; &nbsp;&nbsp;&nbsp;102      u_int16_t ack:1; &nbsp;&nbsp;&nbsp;103      u_int16_t urg:1; &nbsp;&nbsp;&nbsp;104      u_int16_t res2:2; &nbsp;&nbsp;&nbsp;105  #  elif __BYTE_ORDER == __BIG_ENDIAN &nbsp;&nbsp;&nbsp;106      u_int16_t doff:4; &nbsp;&nbsp;&nbsp;107      u_int16_t res1:4; &nbsp;&nbsp;&nbsp;108      u_int16_t res2:2; &nbsp;&nbsp;&nbsp;109      u_int16_t urg:1; &nbsp;&nbsp;&nbsp;110      u_int16_t ack:1; &nbsp;&nbsp;&nbsp;111      u_int16_t psh:1; &nbsp;&nbsp;&nbsp;112      u_int16_t rst:1; &nbsp;&nbsp;&nbsp;113      u_int16_t syn:1; &nbsp;&nbsp;&nbsp;114      u_int16_t fin:1; &nbsp;&nbsp;&nbsp;115  #  else &nbsp;&nbsp;&nbsp;116  #   error "Adjust your <bits/endian.h> defines" &nbsp;&nbsp;&nbsp;117  #  endif &nbsp;&nbsp;&nbsp;118      u_int16_t window; &nbsp;&nbsp;&nbsp;119      u_int16_t check; &nbsp;&nbsp;&nbsp;120      u_int16_t urg_ptr; &nbsp;&nbsp;&nbsp;121  }; &nbsp;&nbsp;&nbsp;122  # endif /* __FAVOR_BSD */

可能与__FAVOR_BSD变量有关，我怎么才可以知道__FAVOR_BSD变量有没有定义？

net_robber

估计头文件，不完整

wangdan1600

在tcp.h中加上
#ifndef __FAVOR_BSD
#define __FAVOR_BSD
#endif
就可以了。。。

可是这有一个潜在的问题，/usr/include/netinet/tcp.h文件是系统范围内公用的，默认没有定义__FAVOR_BSD，我这么直接修改了这个头文件，可能会影响其他程序的编译。

有别的解决方法吗？

[ 本帖最后由 wangdan1600 于 2009-9-27 12:58 编辑 ]

itpriest

现在已经解决了吧，为啥没有答案呢？
在编译时加上 -D_BSD_SOURCE 选项是正确解决方法，当然不能修改系统文件了。

至于为啥直接定义-D__FAVOR_BSD不好用，看一看features.h就知道了
(PS: 不看也知道每个地方进行了#undef  __FAVOR_BSD)

itpriest

抱歉，上面打错了个，是某个地方进行了#undef  __FAVOR_BSD