ndk编译libpcap 1.7.4

android完全菜鸟，绝对的第一次接触，想做手机抓包，在网上搜又是NDK 又是JNI 又是JNETPCAP 完全蒙了，让我这种android和java都弄不明白什么关系的人情何以堪！

静下心想一想，无非是编译一个库，好在C和LINUX都有10年的经验，就直接下最新的libpcap 1.7.4 一步步编译，成功了，写个测试也OK。现将过程写出，以做备忘。

下载安装 android studio、android-ndk-r10d、jdk、libpcap 1.7.4 我这面是全下的WIN7 64对应版本

1. 把libpcap的gz包托到VMWare上的ARCHLINUX里，tar xzf xxxxxx 然后

./configure --disable-ipv6 --disable-usb --disable-bluetooth --disable-canusb --disable-can --disable-dbus
make > res.txt

生成文件如下

gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./pcap-linux.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./pcap-netfilter-linux.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./fad-getad.c
if grep GIT ./VERSION >/dev/null; then \
    read ver <./VERSION; \
    echo $ver | tr -d '\012'; \
    date +_%Y_%m_%d; \
else \
    cat ./VERSION; \
fi | sed -e 's/.*/static const char pcap_version_string[] = "libpcap version &";/' > version.h
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./pcap.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./inet.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./gencode.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./optimize.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./nametoaddr.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./etherent.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./savefile.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./sf-pcap.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./sf-pcap-ng.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./pcap-common.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./bpf_image.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c ./bpf_dump.c
./runlex.sh flex -Ppcap_ -oscanner.c scanner.l
mv scanner.c scanner.c.bottom
cat ./scanner.c.top scanner.c.bottom > scanner.c
bison -y -p pcap_ -d grammar.y
mv y.tab.c grammar.c
mv y.tab.h tokdefs.h
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c scanner.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -Dyylval=pcap_lval -c grammar.c
rm -f bpf_filter.c
ln -s ./bpf/net/bpf_filter.c bpf_filter.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c bpf_filter.c
if grep GIT ./VERSION >/dev/null; then \
    read ver <./VERSION; \
    echo $ver | tr -d '\012'; \
    date +_%Y_%m_%d; \
else \
    cat ./VERSION; \
fi | sed -e 's/.*/char pcap_version[] = "&";/' > version.c
gcc -fpic -I.  -I/usr/include/libnl3 -DHAVE_CONFIG_H  -D_U_="__attribute__((unused))" -g -O2    -c version.c
ar rc libpcap.a pcap-linux.o pcap-netfilter-linux.o fad-getad.o pcap.o inet.o gencode.o optimize.o nametoaddr.o etherent.o savefile.o sf-pcap.o sf-pcap-ng.o pcap-common.o bpf_image.o bpf_dump.o  scanner.o grammar.o bpf_filter.o version.o
ranlib libpcap.a
VER=`cat ./VERSION`; \
MAJOR_VER=`sed 's/\([0-9][0-9]*\)\..*/\1/' ./VERSION`; \
gcc -shared -Wl,-soname,libpcap.so.$MAJOR_VER  \
    -o libpcap.so.$VER pcap-linux.o pcap-netfilter-linux.o fad-getad.o pcap.o inet.o gencode.o optimize.o nametoaddr.o etherent.o savefile.o sf-pcap.o sf-pcap-ng.o pcap-common.o bpf_image.o bpf_dump.o  scanner.o grammar.o bpf_filter.o version.o   -lnl-genl- -lnl-
./config.status --file=pcap-config.tmp:./pcap-config.in
config.status: creating pcap-config.tmp
mv pcap-config.tmp pcap-config
chmod a+x pcap-config

编译过程非常简单，但有五个文件是生成的（scanner.c grammar.c tokdefs.h version.c version.h），全部托到WINDOWS下，放到LIBPCAP源码目录。

另外，还有一个bpf_filter.c在子目录里，LINUX 建了一个软链接，WINDOWS里干脆直接COPY到源码里。

此时已经可以开始编译了，但出错是肯定的。。一个个来

完全不用什么SHELL之类的，就在源码目录里编译以下文件

D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./pcap-linux.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./pcap-netfilter-linux.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./fad-getad.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./pcap.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./inet.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./gencode.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./optimize.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./nametoaddr.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./etherent.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./savefile.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./sf-pcap.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./sf-pcap-ng.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./pcap-common.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./bpf_image.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./bpf_dump.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./scanner.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./bpf_filter.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./version.c
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -Dyylval=pcap_lval -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c grammar.c

1. pcap-netfilter-linux.c 编译出错

D:\libpcap-1.7.>D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -D_U_="__attribute__((unused))" -O2 -fomit-frame-pointer -Wall -pipe -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -c ./pcap-netfilter-linux.c
In file included from D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/stdlib.h::,
                 from ./pcap-netfilter-linux.c::
D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/string.h::: error: expected declaration specifiers or '...' before '(' token
D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/string.h::: error: expected declaration specifiers or '...' before '(' token
D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/string.h::: error: expected declaration specifiers or '...' before '(' token
D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/string.h::: error: expected ')' before ',' token

这需要在pcap-int.h中进行修改

 #define HAVE_STRLCPY 1 //加这一句
 #ifndef HAVE_STRLCPY
 #define strlcpy(x, y, z) \
     (strncpy((x), (y), (z)), \
      ((z) <=  ?  : ((x)[(z) - ] = '\0')), \
      strlen((y)))
 #endif

2. fad-getad.c 编译出错

./fad-getad.c::: fatal error: ifaddrs.h: No such file or directory
compilation terminated.

这个用的接口是getifaddrs 本来就释放不了问题很多，连原来代码里都有提到代码会报错，我看了下里面无非就是列举网卡，就重写了该文件，如下

 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
 /*
  * Copyright (c) 1994, 1995, 1996, 1997, 1998
  *    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 the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *    This product includes software developed by the Computer Systems
  *    Engineering Group at Lawrence Berkeley Laboratory.
  * 4. Neither the name of the University nor of the Laboratory may be used
  *    to endorse or promote products derived from this software without
  *    specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>

 #include <net/if.h>

 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 //#include <linux/if.h>
 //#include <ifaddrs.h>

 #include "pcap-int.h"

 #ifdef HAVE_OS_PROTO_H
 #include "os-proto.h"
 #endif

 /*
  * We don't do this on Solaris 11 and later, as it appears there aren't
  * any AF_PACKET addresses on interfaces, so we don't need this, and
  * we end up including both the OS's <net/bpf.h> and our <pcap/bpf.h>,
  * and their definitions of some data structures collide.
  */
 #if (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET)
 # ifdef HAVE_NETPACKET_PACKET_H
 /* Linux distributions with newer glibc */
 #  include <netpacket/packet.h>
 # else /* HAVE_NETPACKET_PACKET_H */
 /* LynxOS, Linux distributions with older glibc */
 # ifdef __Lynx__
 /* LynxOS */
 #  include <netpacket/if_packet.h>
 # else /* __Lynx__ */
 /* Linux */
 #  include <linux/types.h>
 #  include <linux/if_packet.h>
 # endif /* __Lynx__ */
 # endif /* HAVE_NETPACKET_PACKET_H */
 #endif /* (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET) */

 /*
  * This is fun.
  *
  * In older BSD systems, socket addresses were fixed-length, and
  * "sizeof (struct sockaddr)" gave the size of the structure.
  * All addresses fit within a "struct sockaddr".
  *
  * In newer BSD systems, the socket address is variable-length, and
  * there's an "sa_len" field giving the length of the structure;
  * this allows socket addresses to be longer than 2 bytes of family
  * and 14 bytes of data.
  *
  * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553
  * variant of the old BSD scheme (with "struct sockaddr_storage" rather
  * than "struct sockaddr"), and some use the new BSD scheme.
  *
  * Some versions of GNU libc use neither scheme, but has an "SA_LEN()"
  * macro that determines the size based on the address family.  Other
  * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553
  * but not in the final version).  On the latter systems, we explicitly
  * check the AF_ type to determine the length; we assume that on
  * all those systems we have "struct sockaddr_storage".
  */
 #ifndef SA_LEN
 #ifdef HAVE_SOCKADDR_SA_LEN
 #define SA_LEN(addr)    ((addr)->sa_len)
 #else /* HAVE_SOCKADDR_SA_LEN */
 #ifdef HAVE_SOCKADDR_STORAGE
 static size_t
 get_sa_len( struct sockaddr* addr )
 {
     switch ( addr->sa_family )
     {

 #ifdef AF_INET
         case AF_INET:
             return ( sizeof ( struct sockaddr_in ) );
 #endif

 #ifdef AF_INET6
         case AF_INET6:
             return ( sizeof ( struct sockaddr_in6 ) );
 #endif

 #if (defined(linux) || defined(__Lynx__)) && defined(AF_PACKET)
         case AF_PACKET:
             return ( sizeof ( struct sockaddr_ll ) );
 #endif

         default:
             return ( sizeof ( struct sockaddr ) );
     }
 }
 #define SA_LEN(addr)    (get_sa_len(addr))
 #else /* HAVE_SOCKADDR_STORAGE */
 #define SA_LEN(addr)    (sizeof (struct sockaddr))
 #endif /* HAVE_SOCKADDR_STORAGE */
 #endif /* HAVE_SOCKADDR_SA_LEN */
 #endif /* SA_LEN */

 /*
  * Get a list of all interfaces that are up and that we can open.
  * Returns -1 on error, 0 otherwise.
  * The list, as returned through "alldevsp", may be null if no interfaces
  * could be opened.
  */

 #define MAX_INTERFACE 32
 struct ifreq ifr[MAX_INTERFACE];

 int pcap_findalldevs_interfaces( pcap_if_t** alldevsp, char* errbuf )
 {
     pcap_if_t* devlist;
     int i, rc, sock, ifnum;
     char ifname[IFNAMSIZ];

     struct sockaddr* addr, *netmask, *broadaddr, *dstaddr;
     size_t addr_size, broadaddr_size, dstaddr_size;
     struct ifconf ifc;
     char* p;

     devlist = NULL;

     sock = socket ( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
     if ( sock == - )
     {
         ( void )snprintf( errbuf, PCAP_ERRBUF_SIZE, "sock: %s", pcap_strerror( errno ) );
         return -;
     }

     ifc.ifc_len = sizeof( ifr );
     ifc.ifc_buf = ( caddr_t ) ifr;
     rc = ioctl( sock, SIOCGIFCONF, &ifc );
     if ( rc == - )
     {
         ( void )snprintf( errbuf, PCAP_ERRBUF_SIZE, "ioctl: %s", pcap_strerror( errno ) );
         close( sock );
         return -;
     }

     ifnum = ifc.ifc_len / sizeof ( struct ifreq );
     if ( ifnum > MAX_INTERFACE )
     {
         ifnum = MAX_INTERFACE;
     }

     for ( i = ; i < ifnum; i ++ )
     {
         rc = ioctl( sock, SIOCGIFFLAGS, ifr + i );
         if ( rc == - )
         {
             ( void )snprintf( errbuf, PCAP_ERRBUF_SIZE, "ioctl: %s", pcap_strerror( errno ) );
             break;
         }

         //ip netmask
         rc = ioctl ( sock, SIOCGIFADDR, ifr + i );
         if ( rc != - )
         {
             addr = &ifr[i].ifr_addr;
             addr_size = SA_LEN( addr );

             ioctl ( sock, SIOCGIFNETMASK, ifr + i );
             netmask = &ifr[i].ifr_netmask;
         }
         else
         {
             continue;
         }

         // broadcast
         if ( ( ifr[i].ifr_flags & IFF_BROADCAST ) && ( rc = ioctl ( sock, SIOCGIFBRDADDR, ifr + i ) ) != - )
         {
             broadaddr = &ifr[i].ifr_broadaddr;
             broadaddr_size = SA_LEN( broadaddr );
         }
         else
         {
             broadaddr = NULL;
             broadaddr_size = ;
         }

         // p2p
         if ( ( ifr[i].ifr_flags & IFF_POINTOPOINT ) && ( rc = ioctl ( sock, SIOCGIFDSTADDR, ifr + i ) ) != - )
         {
             dstaddr = &ifr[i].ifr_dstaddr;
             dstaddr_size = SA_LEN( dstaddr );
         }
         else
         {
             dstaddr = NULL;
             dstaddr_size = ;
         }

         // ifname
         memset( ifname, , sizeof( ifname ) );
         strcpy( ifname, ifr[i].ifr_name );

         /*p = strchr( ifname, ':' );
         if ( p != NULL )
         {
             *p = 0;
         }*/

         printf("add [%d][%s]\n", i, ifname);
         if ( add_addr_to_iflist( &devlist, ifname,
                                  ifr[i].ifr_flags, addr, addr_size, netmask, addr_size,
                                  broadaddr, broadaddr_size, dstaddr, dstaddr_size,
                                  errbuf ) <  )
         {
             rc = -;
             break;
         }
     }

     if ( rc == - )
     {
         if ( devlist != NULL )
         {
             pcap_freealldevs( devlist );
             devlist = NULL;
         }
     }

     *alldevsp = devlist;
     close( sock );
     return ;
 }

3. pcap.c报错

D:\libpcap-1.7.\pcap.c: In function 'pcap_strerror':
D:\libpcap-1.7.\pcap.c::: error: conflicting types for 'sys_errlist'
D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/stdio.h::: note: previous declaration of 'sys_errlist' was here

修改该函数

 const char *
 pcap_strerror(int errnum)
 {
 #define HAVE_STRERROR 1//加这一句
 #ifdef HAVE_STRERROR
     return (strerror(errnum));
 #else
     extern int sys_nerr;
     extern const char *const sys_errlist[];
     static char ebuf[++];

     if ((unsigned int)errnum < sys_nerr)
         return ((char *)sys_errlist[errnum]);
     (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
     return(ebuf);
 #endif
 }

4. inet.c警告

---------- ndk-gcc ----------
D:\libpcap-1.7.\inet.c::: warning: "INT_MAX" redefined [enabled by default]
D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include/sys/limits.h::: note: this is the location of the previous definition

修改为

#define HAVE_LIMITS_H 1 //加这一句
#ifdef HAVE_LIMITS_H
#include <limits.h>
#else
#define INT_MAX        2147483647
#endif

5. gencode.c警告

一大堆，分支可能无法RETURN 变量可能未初始化之类的，不影响，不作修改！

然后开始链接，这里恶心了好久.后来想想也明白了，这个就是嵌入式板子上的一个LINUX系统，没有标准C库。一定要加-nostdlib

还有就是体现出菜鸟本色的东西了，crtend_android.o crtbegin_dynamic.o 这两个东西不知道干什么的，在网上看了下，好像都要，应该是启动代码类的，本来可能是后缀S的汇编。。所以直接COPY到源码文件夹。至于为什么用dynamic，只是因为我要编译SO。不过后缀有SO的可能更好，纠结了半天用的是crtend_so.o crtbegin_so.o。后面测试程序再用上面的两个好了。

然后执行

D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -nostdlib -Bdynamic -shared -Wl,-soname,libpcap.so -o libpcap.so pcap-linux.o pcap-netfilter-linux.o fad-getad.o pcap.o inet.o gencode.o optimize.o nametoaddr.o etherent.o savefile.o sf-pcap.o sf-pcap-ng.o pcap-common.o bpf_image.o bpf_dump.o scanner.o grammar.o bpf_filter.o version.o crtend_so.o crtbegin_so.o -LD:\Android\android-ndk-r10d\platforms\android-19\arch-arm\usr\lib -lc -ldl -llog -lgcc -lm -landroid -lz

顺利生成libpcap.so

然后写个程序测下

 //netpkghdr.h
 #ifndef _NET_PKG_HDR_H_
 #define _NET_PKG_HDR_H_

 #define ETHERTYPE_IP 0x0008        // IP协议  (0x0800的网络序)
 #define TCP_PROTOCAL 0x0006        // TCP协议 (0x0600的网络序)
 #define BUFF_MAX_LEN 0x10000       // 最大包长

 #pragma pack(push, 1)

 // ethernet header
 typedef struct ether_header
 {
     unsigned char  dst[];         // 目标MAC
     unsigned char  src[];         // 源MAC
     unsigned short type;           // 上层协议标识
 } eth_hdr;

 // ipv4 address
 typedef struct ip_address
 {
     unsigned char b1, b2, b3, b4;
 } ip_addr;

 // ipv4 header
 typedef struct ip_header
 {
     unsigned char  ver_ihl;        // 版本信息(4)头长度(4)
     unsigned char  tos;            // 服务类型
     unsigned short len;            // 数据包长度
     unsigned short id;             // 数据包标识
     unsigned short slice;          // 片偏移
     unsigned char  ttl;            // ttl
     unsigned char  proto;          // 协议
     unsigned short sum;            // 校验和
     ip_addr        saddr;          // 源IP
     ip_addr        daddr;          // 目标IP
 } ip_hdr;

 // tcp header
 typedef struct tcp_header
 {
     unsigned short sport;          // 源端口
     unsigned short dport;          // 目标端口
     unsigned int   seq;            // 序列号
     unsigned int   ack;            // 应答
     unsigned short len_code;       // TCP头长度(4)保留(6)标志(6)
     unsigned short window;         // 窗口大小
     unsigned short sum;            // 校验和
     unsigned short urp;            // 紧急数据偏移
 } tcp_hdr;

 // udp header
 typedef struct udp_header
 {
     unsigned short sport;          // 源端口
     unsigned short dport;          // 目标端口
     unsigned short len;            // 包长
     unsigned short sum;            // 校验和
 } udp_hdr;

 #pragma pack(pop)

 #endif /* _NET_PKG_HDR_H_ */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <pcap.h>
 #include "netpkghdr.h"

 unsigned char g_buffer[BUFF_MAX_LEN] = {};

 pcap_t* get_pcap( const char* name )
 {
     pcap_if_t* ifs;
     pcap_if_t* d;
     pcap_t* pcap;
     char errbuff[PCAP_ERRBUF_SIZE];

     if ( pcap_findalldevs( &ifs, errbuff ) == - )
     {
         fprintf( stderr, "pcap_findalldevs [%s]\n", errbuff );
         return NULL;
     }

     for ( d = ifs; d; d = d->next )
     {
         if ( memcmp( d->name, name, strlen( name ) ) ==  )
         {
             break;
         }
     }

     pcap = pcap_open_live( d->name, \
                            BUFF_MAX_LEN, \
                            , \
                            , \
                            errbuff );

     pcap_freealldevs( ifs );

     if ( pcap == NULL )
     {
         fprintf( stderr, "pcap_open_live [%s]\n", errbuff );
         return NULL;
     }

     return pcap;
 }

 int main()
 {
     int rc;
     pcap_t* pcap;
     struct bpf_program bpf;

     struct pcap_pkthdr* header;
     const unsigned char* pkt_data;

     eth_hdr* eth;

     ip_hdr* ip;
     unsigned short ip_hdr_len;

     tcp_hdr* tcp;
     unsigned short tcp_hdr_len;
     unsigned short tcp_data_len;
     unsigned char* tcp_pkt_data;

     if ( ( pcap = get_pcap( "wlan" ) ) == NULL )
     {
         return -;
     }

     if ( pcap_compile( pcap, &bpf, "tcp port 80", ,  ) <  )
     {
         fprintf( stderr, "pcap_compile error\n" );
         return -;
     }

     if ( pcap_setfilter( pcap, &bpf ) <  )
     {
         fprintf( stderr, "pcap_setfilter\n" );
         return -;
     }

     while ( ( rc = pcap_next_ex( pcap, &header, &pkt_data ) ) >=  )
     {
         if ( rc ==  )
         {
             continue;
         }

         eth = ( eth_hdr* )pkt_data;

         ip = ( ip_hdr* )( eth +  );
         ip_hdr_len = ( ( ip->ver_ihl & 0x0F ) <<  );

         tcp = ( tcp_hdr* )( pkt_data + sizeof( eth_hdr ) + ip_hdr_len );
         tcp_hdr_len = ( ( tcp->len_code & 0x00F0 ) >>  );
         tcp_data_len = header->len - sizeof( eth_hdr ) - ip_hdr_len - tcp_hdr_len;
         tcp_pkt_data = ( unsigned char* )tcp + tcp_hdr_len;

         if ( tcp_data_len <  || \
                 ( strncmp( ( char* )tcp_pkt_data, "GET",  ) && \
                   strncmp( ( char* )tcp_pkt_data, "POST",  ) && \
                   strncmp( ( char* )tcp_pkt_data, "HTTP/1.1",  ) ) )
         {
             continue;
         }

         memcpy( g_buffer, tcp_pkt_data, tcp_data_len );
         g_buffer[tcp_data_len] = ;

         printf( "==============================================\n" );
         printf( "%s\n", ( char* )g_buffer );
         printf( "**********************************************\n\n" );
     }

     pcap_close( pcap );

     return ;
 }

编译之

D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -DNDEBUG -O2 -fomit-frame-pointer -Wall -pipe -c main.c -I. -ID:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\include -I./pcap
D:\Android\android-ndk-r10d\toolchains\arm-linux-androideabi-4.6\prebuilt\windows-x86_64\bin\arm-linux-androideabi-gcc.exe -nostdlib -Bdynamic -Wl,-dynamic-linker,/system/bin/linker -o hello main.o D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\lib\crtend_android.o D:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\lib\crtbegin_dynamic.o -L. -LD:\Android\android-ndk-r10d\platforms\android-\arch-arm\usr\lib -lc -ldl -llog -lgcc -lm -landroid -lz -lpcap

报错！！！

d:/android/android-ndk-r10d/toolchains/arm-linux-androideabi-4.6/prebuilt/windows-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld.exe: ./libpcap.so: error: undefined reference to 'pcap_snprintf'
d:/android/android-ndk-r10d/toolchains/arm-linux-androideabi-4.6/prebuilt/windows-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld.exe: ./libpcap.so: error: undefined reference to 'pcap_vsnprintf'
collect2: ld returned  exit status

明显是PCAP源码里这两个函数有问题，回头再去改源码

同样是修改pcap-int.h

#define HAVE_SNPRINTF 1 //添加这一句
#if !defined(HAVE_SNPRINTF)
#define snprintf pcap_snprintf
extern int snprintf (char *, size_t, const char *, ...);
#endif

#define HAVE_VSNPRINTF 1 //添加这一句
#if !defined(HAVE_VSNPRINTF)
#define vsnprintf pcap_vsnprintf
extern int vsnprintf (char *, size_t, const char *, va_list ap);
#endif

重新生成SO,并编译程序 ...顺利生成hello

然后用传说中的adb push到里面(这个查了半小时，不知道ADB是什么)

用RE把so放/system/lib 改权限

用RE修改hello权限

adb shell，发现和LINUX一样一样的。。。

执行之

明天再写几个JNI的东西，把这一堆PCAP的函数包成我想要的，然后写JAVA。。。再然后就OK了。。

闲扯几句，开始看了眼JNI吓一跳，后来用和上面一要最土的方法，试了下，发现和C与LUA交互非常像，只是更智能点。