net/pcap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2019 Ramon Fried <rfried.dev@gmail.com>
   4  */
   5
   6 #include <net.h>
   7 #include <net/pcap.h>
   8 #include <time.h>
   9 #include <linux/errno.h>
  10 #include <asm/io.h>
  11
  12 #define LINKTYPE_ETHERNET       1
  13
  14 static bool initialized;
  15 static bool running;
  16 static bool buffer_full;
  17 static void *buf;
  18 static unsigned int max_size;
  19 static unsigned int pos;
  20
  21 static unsigned long incoming_count;
  22 static unsigned long outgoing_count;
  23
  24 struct pcap_header {
  25         u32 magic;
  26         u16 version_major;
  27         u16 version_minor;
  28         s32 thiszone;
  29         u32 sigfigs;
  30         u32 snaplen;
  31         u32 network;
  32 };
  33
  34 struct pcap_packet_header {
  35         u32 ts_sec;
  36         u32 ts_usec;
  37         u32 incl_len;
  38         u32 orig_len;
  39 };
  40
  41 static struct pcap_header file_header = {
  42         .magic = 0xa1b2c3d4,
  43         .version_major = 2,
  44         .version_minor = 4,
  45         .snaplen = 65535,
  46         .network = LINKTYPE_ETHERNET,
  47 };
  48
  49 int pcap_init(phys_addr_t paddr, unsigned long size)
  50 {
  51         buf = map_physmem(paddr, size, 0);
  52         if (!buf) {
  53                 printf("Failed mapping PCAP memory\n");
  54                 return -ENOMEM;
  55         }
  56
  57         printf("PCAP capture initialized: addr: 0x%lx max length: %lu\n",
  58                (unsigned long)buf, size);
  59
  60         memcpy(buf, &file_header, sizeof(file_header));
  61         pos = sizeof(file_header);
  62         max_size = size;
  63         initialized = true;
  64         running = false;
  65         buffer_full = false;
  66         incoming_count = 0;
  67         outgoing_count = 0;
  68         return 0;
  69 }
  70
  71 int pcap_start_stop(bool start)
  72 {
  73         if (!initialized) {
  74                 printf("error: pcap was not initialized\n");
  75                 return -ENODEV;
  76         }
  77
  78         running = start;
  79
  80         return 0;
  81 }
  82
  83 int pcap_clear(void)
  84 {
  85         if (!initialized) {
  86                 printf("error: pcap was not initialized\n");
  87                 return -ENODEV;
  88         }
  89
  90         pos = sizeof(file_header);
  91         incoming_count = 0;
  92         outgoing_count = 0;
  93         buffer_full = false;
  94
  95         printf("pcap capture cleared\n");
  96         return 0;
  97 }
  98
  99 int pcap_post(const void *packet, size_t len, bool outgoing)
 100 {
 101         struct pcap_packet_header header;
 102         u64 cur_time = timer_get_us();
 103
 104         if (!initialized || !running || !buf)
 105                 return -ENODEV;
 106
 107         if (buffer_full)
 108                 return -ENOMEM;
 109
 110         if ((pos + len + sizeof(header)) >= max_size) {
 111                 buffer_full = true;
 112                 printf("\n!!! Buffer is full, consider increasing buffer size !!!\n");
 113                 return -ENOMEM;
 114         }
 115
 116         header.ts_sec = cur_time / 1000000;
 117         header.ts_usec = cur_time % 1000000;
 118         header.incl_len = len;
 119         header.orig_len = len;
 120
 121         memcpy(buf + pos, &header, sizeof(header));
 122         pos += sizeof(header);
 123         memcpy(buf + pos, packet, len);
 124         pos += len;
 125
 126         if (outgoing)
 127                 outgoing_count++;
 128         else
 129                 incoming_count++;
 130
 131         env_set_hex("pcapsize", pos);
 132
 133         return 0;
 134 }
 135
 136 int pcap_print_status(void)
 137 {
 138         if (!initialized) {
 139                 printf("pcap was not initialized\n");
 140                 return -ENODEV;
 141         }
 142         printf("PCAP status:\n");
 143         printf("\tInitialized addr: 0x%lx\tmax length: %u\n",
 144                (unsigned long)buf, max_size);
 145         printf("\tStatus: %s.\t file size: %u\n", running ? "Active" : "Idle",
 146                pos);
 147         printf("\tIncoming packets: %lu Outgoing packets: %lu\n",
 148                incoming_count, outgoing_count);
 149
 150         return 0;
 151 }
 152
 153 bool pcap_active(void)
 154 {
 155         return running;
 156 }