如何打印每个数据包的前34个字节（以太网和IP头）（EtherType：0x0806，协议：ARP）？ [英] How to printk the first 34 bytes (Ethernet and IP headers) of each packet (EtherType: 0x0806, Protocol: ARP)?
本文介绍了如何打印每个数据包的前34个字节（以太网和IP头）（EtherType：0x0806，协议：ARP）？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
- 操作系统：Ubuntu 15.10桌面（64位）
- 内核：4.3
- 驱动程序：无线
- 路径： / net / mac80211 / rx.c
- Operating system: Ubuntu 15.10 Desktop (64-bit)
- Kernel: 4.3
- Driver: Wireless
- Path: /net/mac80211/rx.c
以下是我当前的实现（ int i = 0; 就在 struct sta_info * dsta; 之后， packet_number ++; 就在
Below is my current implementation (int i = 0; is just after struct sta_info *dsta;, and packet_number++; is just before skb = rx->skb; in the original rx.c file):
#include <linux/ip.h>
#include <linux/byteorder/generic.h>
unsigned int packet_number = 1;
(etc.)
static void ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
{
(etc.)
int i = 0;
unsigned int *byte_pointer;
unsigned long byte_contents = 0;
if (ntohs(ehdr->h_proto) == 0x0806) {
printk("Packet %d:", packet_number);
for (i = 0; i < 34; i++) {
byte_pointer = (unsigned int *) (rx->skb->data + i);
byte_contents = (unsigned long) (&byte_pointer);
printk(" %lx", byte_contents);
}
}
printk("\n");
packet_number++;
然而，在运行dmesg以显示printk输出后，这就是我得到的：
However, after running dmesg to display the printk outputs, this is what I get:
[ 103.373847] Packet 6: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 103.375720] Packet 7: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 103.572086] Packet 8: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 103.913790] Packet 12: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 108.940615] Packet 20: ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8
[ 114.221127] Packet 28: ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8
[ 143.390755] Packet 1354: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 144.394113] Packet 1401: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 194.730646] Packet 2041: ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8
[ 208.784474] Packet 2059: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 247.409613] Packet 2130: ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8
[ 272.241113] Packet 2171: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 272.241957] Packet 2172: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 272.648982] Packet 2174: ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8 ffff88007bd17bd8
[ 273.877091] Packet 2180: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
[ 273.878104] Packet 2181: ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8 ffff88007c603cb8
这些是我想代替输出：
Packet xx: 74 46 a4 08 06 ...
Packet xx: 55 32 3e 45 98 ...
Packet xx: 00 1b 2c 70 55 ...
rx-> skb-> data的数据类型是 unsigned char * ，为了使它与％x兼容，我不得不做那些演员表并最终需要使用unsigned long和％lx代替停止编译警告。
The data type of rx->skb->data is an unsigned char *, and in order to make it compatible with %x, I had to do those casts and ended up needing to use unsigned long and %lx instead to stop compilation warnings from occurring.
你能告诉我我做错了什么，以及如何打印前34个字节（以太网）和每个数据包的IP头（EtherType：0x0806，协议：ARP）？
Can you please tell me what I am doing wrong, and how I can printk the first 34 bytes (Ethernet and IP headers) of each packet (EtherType: 0x0806, Protocol: ARP)?
推荐答案
你必须使用％* ph 说明符或 print_hex_dump（）如果要将其放在多行上。在任何情况下，这个都不是为时间关键部分设计的。因此，在这种情况下，您必须使用相应的 trace_printk（）调用切换到跟踪点。
You have to use either %*ph specifier or print_hex_dump() if you want to place it on several lines. In any case this one is not designed for time-critical parts. So, in that case you have to switch to trace points with corresponding trace_printk() calls.
对于慢速示例如下。
pr_info("Packet %d: %34ph\n", packet_number, rx->skb->data);
或
pr_info("Packet %d:\n", packet_number);
print_hex_dump(KERN_INFO, "Packet:", DUMP_PREFIX_OFFSET, 16, 1, rx->skb->data, 34, false);
这篇关于如何打印每个数据包的前34个字节（以太网和IP头）（EtherType：0x0806，协议：ARP）？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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