arch/um/drivers/pcap_user.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike <jdike@karaya.com>
   3  * Licensed under the GPL.
   4  */
   5
   6 #include <unistd.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <errno.h>
  10 #include <pcap.h>
  11 #include <asm/types.h>
  12 #include "net_user.h"
  13 #include "pcap_user.h"
  14 #include "user.h"
  15 #include "um_malloc.h"
  16
  17 #define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
  18
  19 #define PCAP_FD(p) (*(int *)(p))
  20
  21 static int pcap_user_init(void *data, void *dev)
  22 {
  23         struct pcap_data *pri = data;
  24         pcap_t *p;
  25         char errors[PCAP_ERRBUF_SIZE];
  26
  27         p = pcap_open_live(pri->host_if, MAX_PACKET, pri->promisc, 0, errors);
  28         if(p == NULL){
  29                 printk("pcap_user_init : pcap_open_live failed - '%s'\n",
  30                        errors);
  31                 return -EINVAL;
  32         }
  33
  34         pri->dev = dev;
  35         pri->pcap = p;
  36         return 0;
  37 }
  38
  39 static int pcap_open(void *data)
  40 {
  41         struct pcap_data *pri = data;
  42         __u32 netmask;
  43         int err;
  44
  45         if(pri->pcap == NULL)
  46                 return -ENODEV;
  47
  48         if(pri->filter != NULL){
  49                 err = dev_netmask(pri->dev, &netmask);
  50                 if(err < 0){
  51                         printk("pcap_open : dev_netmask failed\n");
  52                         return -EIO;
  53                 }
  54
  55                 pri->compiled = um_kmalloc(sizeof(struct bpf_program));
  56                 if(pri->compiled == NULL){
  57                         printk("pcap_open : kmalloc failed\n");
  58                         return -ENOMEM;
  59                 }
  60
  61                 err = pcap_compile(pri->pcap,
  62                                    (struct bpf_program *) pri->compiled,
  63                                    pri->filter, pri->optimize, netmask);
  64                 if(err < 0){
  65                         printk("pcap_open : pcap_compile failed - '%s'\n",
  66                                pcap_geterr(pri->pcap));
  67                         return -EIO;
  68                 }
  69
  70                 err = pcap_setfilter(pri->pcap, pri->compiled);
  71                 if(err < 0){
  72                         printk("pcap_open : pcap_setfilter failed - '%s'\n",
  73                                pcap_geterr(pri->pcap));
  74                         return -EIO;
  75                 }
  76         }
  77
  78         return PCAP_FD(pri->pcap);
  79 }
  80
  81 static void pcap_remove(void *data)
  82 {
  83         struct pcap_data *pri = data;
  84
  85         if(pri->compiled != NULL)
  86                 pcap_freecode(pri->compiled);
  87
  88         pcap_close(pri->pcap);
  89 }
  90
  91 struct pcap_handler_data {
  92         char *buffer;
  93         int len;
  94 };
  95
  96 static void handler(u_char *data, const struct pcap_pkthdr *header,
  97                     const u_char *packet)
  98 {
  99         int len;
 100
 101         struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
 102
 103         len = hdata->len < header->caplen ? hdata->len : header->caplen;
 104         memcpy(hdata->buffer, packet, len);
 105         hdata->len = len;
 106 }
 107
 108 int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
 109 {
 110         struct pcap_handler_data hdata = ((struct pcap_handler_data)
 111                                           { .buffer     = buffer,
 112                                             .len        = len });
 113         int n;
 114
 115         n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);
 116         if(n < 0){
 117                 printk("pcap_dispatch failed - %s\n", pcap_geterr(pri->pcap));
 118                 return -EIO;
 119         }
 120         else if(n == 0)
 121                 return 0;
 122         return hdata.len;
 123 }
 124
 125 const struct net_user_info pcap_user_info = {
 126         .init           = pcap_user_init,
 127         .open           = pcap_open,
 128         .close          = NULL,
 129         .remove         = pcap_remove,
 130         .set_mtu        = NULL,
 131         .add_address    = NULL,
 132         .delete_address = NULL,
 133         .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
 134 };