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 void 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;
  32         }
  33
  34         pri->dev = dev;
  35         pri->pcap = p;
  36 }
  37
  38 static int pcap_open(void *data)
  39 {
  40         struct pcap_data *pri = data;
  41         __u32 netmask;
  42         int err;
  43
  44         if(pri->pcap == NULL)
  45                 return(-ENODEV);
  46
  47         if(pri->filter != NULL){
  48                 err = dev_netmask(pri->dev, &netmask);
  49                 if(err < 0){
  50                         printk("pcap_open : dev_netmask failed\n");
  51                         return(-EIO);
  52                 }
  53
  54                 pri->compiled = um_kmalloc(sizeof(struct bpf_program));
  55                 if(pri->compiled == NULL){
  56                         printk("pcap_open : kmalloc failed\n");
  57                         return(-ENOMEM);
  58                 }
  59
  60                 err = pcap_compile(pri->pcap,
  61                                    (struct bpf_program *) pri->compiled,
  62                                    pri->filter, pri->optimize, netmask);
  63                 if(err < 0){
  64                         printk("pcap_open : pcap_compile failed - '%s'\n",
  65                                pcap_geterr(pri->pcap));
  66                         return(-EIO);
  67                 }
  68
  69                 err = pcap_setfilter(pri->pcap, pri->compiled);
  70                 if(err < 0){
  71                         printk("pcap_open : pcap_setfilter failed - '%s'\n",
  72                                pcap_geterr(pri->pcap));
  73                         return(-EIO);
  74                 }
  75         }
  76
  77         return(PCAP_FD(pri->pcap));
  78 }
  79
  80 static void pcap_remove(void *data)
  81 {
  82         struct pcap_data *pri = data;
  83
  84         if(pri->compiled != NULL)
  85                 pcap_freecode(pri->compiled);
  86
  87         pcap_close(pri->pcap);
  88 }
  89
  90 struct pcap_handler_data {
  91         char *buffer;
  92         int len;
  93 };
  94
  95 static void handler(u_char *data, const struct pcap_pkthdr *header,
  96                     const u_char *packet)
  97 {
  98         int len;
  99
 100         struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
 101
 102         len = hdata->len < header->caplen ? hdata->len : header->caplen;
 103         memcpy(hdata->buffer, packet, len);
 104         hdata->len = len;
 105 }
 106
 107 int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
 108 {
 109         struct pcap_handler_data hdata = ((struct pcap_handler_data)
 110                                           { .buffer     = buffer,
 111                                             .len        = len });
 112         int n;
 113
 114         n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);
 115         if(n < 0){
 116                 printk("pcap_dispatch failed - %s\n", pcap_geterr(pri->pcap));
 117                 return(-EIO);
 118         }
 119         else if(n == 0)
 120                 return(0);
 121         return(hdata.len);
 122 }
 123
 124 const struct net_user_info pcap_user_info = {
 125         .init           = pcap_user_init,
 126         .open           = pcap_open,
 127         .close          = NULL,
 128         .remove         = pcap_remove,
 129         .set_mtu        = NULL,
 130         .add_address    = NULL,
 131         .delete_address = NULL,
 132         .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
 133 };
 134
 135 /*
 136  * Overrides for Emacs so that we follow Linus's tabbing style.
 137  * Emacs will notice this stuff at the end of the file and automatically
 138  * adjust the settings for this buffer only.  This must remain at the end
 139  * of the file.
 140  * ---------------------------------------------------------------------------
 141  * Local variables:
 142  * c-file-style: "linux"
 143  * End:
 144  */