通过读取 /proc/self/net/dev 或者 /proc/net/dev 来得到应用程序流量统计.

获取单个APP流量的方法目前Android没有提供API，但可以同抓包来分析得到pid，从而确定是哪个APP产生的流量。

限制APP访问网络可以用iptables脚本来做到，DroidWallhttp://code.google.com/p/droidwall/?用的就是iptables脚本+白名单来控制网络访问的。仅是通过/proc/net/dev读取其中的数据.(转载)

#include 
#include 
#include

void skipline(FILE *f) 
{ 
  int ch; 
  do { 
    ch = getc(f); 
  } while ( ch != 'n' && ch != EOF ); 
}

int main(int argc, char *argv[]) 
{ 
  FILE *pnd; 
  char buffer[BUFSIZ]; 
  char *interface; 
  struct ifinfo { 
    char name[8]; 
    unsigned int r_bytes, r_pkt, r_err, r_drop, r_fifo, r_frame; 
    unsigned int r_compr, r_mcast; 
    unsigned int x_bytes, x_pkt, x_err, x_drop, x_fifo, x_coll; 
    unsigned int x_carrier, x_compr; 
  } ifc; 
  unsigned long long bin, bout, lbin, lbout; 
  int first;

  if ( argc != 2 ) { 
    fprintf(stderr, "Usage: %s interfacen", argv[0]); 
    exit(1); 
  }

  interface = argv[1];

  first = 1; 
  lbin = 0; lbout = 0;

  while ( 1 ) { 
    pnd = fopen("/proc/net/dev", "r"); 
    if ( !pnd ) { 
      fprintf(stderr, "%s: /proc/net/dev: %s", argv[0], strerror(errno)); 
      exit(1); 
    }

    /* Skip header */ 
    skipline(pnd); 
    skipline(pnd);

    /* Get interface info */ 
    do { 
      if ( fscanf(pnd, " %6[^:]:%u %u %u %u %u %u %u %u %u %u %u %u %u %u %u", 
                  &ifc.name, 
                  &ifc.r_bytes, &ifc.r_pkt, &ifc.r_err, &ifc.r_drop, 
                  &ifc.r_fifo, &ifc.r_frame, &ifc.r_compr, &ifc.r_mcast, 
                  &ifc.x_bytes, &ifc.x_pkt, &ifc.x_err, &ifc.x_drop, 
                  &ifc.x_fifo, &ifc.x_coll, &ifc.x_carrier, &ifc.x_compr) 
           != 16 ) { 
        exit(200); 
      } 
      skipline(pnd); 
    } while ( strcmp(ifc.name, interface) );

    bin  = ifc.r_bytes + (lbin & ~0xffffffffULL); 
    bout = ifc.x_bytes + (lbout & ~0xffffffffULL);

    if ( bin < lbin ) 
      bin += (1ULL << 32); 
    if ( bout < lbout ) 
      bout += (1ULL << 32);

    if ( !first ) { 
      printf("%d %Lu %Lun", time(NULL), (bout-lbout)*8, (bin-lbin)*8); 
      fflush(stdout); 
    } else { 
      first = 0; 
    }

    lbin = bin;  lbout = bout;

    fclose(pnd);

    sleep(1); 
  } 
}

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