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
  16 #define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
  17
  18 #define PCAP_FD(p) (*(int *)(p))
  19
  20 static void pcap_user_init(void *data, void *dev)
  21 {
  22         struct pcap_data *pri = data;
  23         pcap_t *p;
  24         char errors[PCAP_ERRBUF_SIZE];
  25
  26         p = pcap_open_live(pri->host_if, MAX_PACKET, pri->promisc, 0, errors);
  27         if(p == NULL){
  28                 printk("pcap_user_init : pcap_open_live failed - '%s'\n",
  29                        errors);
  30                 return;
  31         }
  32
  33         pri->dev = dev;
  34         pri->pcap = p;
  35 }
  36
  37 static int pcap_open(void *data)
  38 {
  39         struct pcap_data *pri = data;
  40         __u32 netmask;
  41         int err;
  42
  43         if(pri->pcap == NULL)
  44                 return(-ENODEV);
  45
  46         if(pri->filter != NULL){
  47                 err = dev_netmask(pri->dev, &netmask);
  48                 if(err < 0){
  49                         printk("pcap_open : dev_netmask failed\n");
  50                         return(-EIO);
  51                 }
  52
  53                 pri->compiled = um_kmalloc(sizeof(struct bpf_program));
  54                 if(pri->compiled == NULL){
  55                         printk("pcap_open : kmalloc failed\n");
  56                         return(-ENOMEM);
  57                 }
  58
  59                 err = pcap_compile(pri->pcap,
  60                                    (struct bpf_program *) pri->compiled,
  61                                    pri->filter, pri->optimize, netmask);
  62                 if(err < 0){
  63                         printk("pcap_open : pcap_compile failed - '%s'\n",
  64                                pcap_geterr(pri->pcap));
  65                         return(-EIO);
  66                 }
  67
  68                 err = pcap_setfilter(pri->pcap, pri->compiled);
  69                 if(err < 0){
  70                         printk("pcap_open : pcap_setfilter failed - '%s'\n",
  71                                pcap_geterr(pri->pcap));
  72                         return(-EIO);
  73                 }
  74         }
  75
  76         return(PCAP_FD(pri->pcap));
  77 }
  78
  79 static void pcap_remove(void *data)
  80 {
  81         struct pcap_data *pri = data;
  82
  83         if(pri->compiled != NULL)
  84                 pcap_freecode(pri->compiled);
  85
  86         pcap_close(pri->pcap);
  87 }
  88
  89 struct pcap_handler_data {
  90         char *buffer;
  91         int len;
  92 };
  93
  94 static void handler(u_char *data, const struct pcap_pkthdr *header,
  95                     const u_char *packet)
  96 {
  97         int len;
  98
  99         struct pcap_handler_data *hdata = (struct pcap_handler_data *) data;
 100
 101         len = hdata->len < header->caplen ? hdata->len : header->caplen;
 102         memcpy(hdata->buffer, packet, len);
 103         hdata->len = len;
 104 }
 105
 106 int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri)
 107 {
 108         struct pcap_handler_data hdata = ((struct pcap_handler_data)
 109                                           { .buffer     = buffer,
 110                                             .len        = len });
 111         int n;
 112
 113         n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata);
 114         if(n < 0){
 115                 printk("pcap_dispatch failed - %s\n", pcap_geterr(pri->pcap));
 116                 return(-EIO);
 117         }
 118         else if(n == 0)
 119                 return(0);
 120         return(hdata.len);
 121 }
 122
 123 const struct net_user_info pcap_user_info = {
 124         .init           = pcap_user_init,
 125         .open           = pcap_open,
 126         .close          = NULL,
 127         .remove         = pcap_remove,
 128         .set_mtu        = NULL,
 129         .add_address    = NULL,
 130         .delete_address = NULL,
 131         .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
 132 };
 133
 134 /*
 135  * Overrides for Emacs so that we follow Linus's tabbing style.
 136  * Emacs will notice this stuff at the end of the file and automatically
 137  * adjust the settings for this buffer only.  This must remain at the end
 138  * of the file.
 139  * ---------------------------------------------------------------------------
 140  * Local variables:
 141  * c-file-style: "linux"
 142  * End:
 143  */