1/* 2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL. 4 */ 5 6#include <errno.h> 7#include <pcap.h> 8#include <string.h> 9#include <asm/types.h> 10#include "net_user.h" 11#include "pcap_user.h" 12#include "kern_constants.h" 13#include "um_malloc.h" 14#include "user.h" 15 16#define PCAP_FD(p) (*(int *)(p)) 17 18static int pcap_user_init(void *data, void *dev) 19{ 20 struct pcap_data *pri = data; 21 pcap_t *p; 22 char errors[PCAP_ERRBUF_SIZE]; 23 24 p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER, 25 pri->promisc, 0, errors); 26 if (p == NULL) { 27 printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - " 28 "'%s'\n", errors); 29 return -EINVAL; 30 } 31 32 pri->dev = dev; 33 pri->pcap = p; 34 return 0; 35} 36 37static 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(UM_KERN_ERR "pcap_open : dev_netmask failed\n"); 50 return -EIO; 51 } 52 53 pri->compiled = uml_kmalloc(sizeof(struct bpf_program), 54 UM_GFP_KERNEL); 55 if (pri->compiled == NULL) { 56 printk(UM_KERN_ERR "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(UM_KERN_ERR "pcap_open : pcap_compile failed - " 65 "'%s'\n", pcap_geterr(pri->pcap)); 66 goto out; 67 } 68 69 err = pcap_setfilter(pri->pcap, pri->compiled); 70 if (err < 0) { 71 printk(UM_KERN_ERR "pcap_open : pcap_setfilter " 72 "failed - '%s'\n", pcap_geterr(pri->pcap)); 73 goto out; 74 } 75 } 76 77 return PCAP_FD(pri->pcap); 78 79 out: 80 kfree(pri->compiled); 81 return -EIO; 82} 83 84static void pcap_remove(void *data) 85{ 86 struct pcap_data *pri = data; 87 88 if (pri->compiled != NULL) 89 pcap_freecode(pri->compiled); 90 91 if (pri->pcap != NULL) 92 pcap_close(pri->pcap); 93} 94 95struct pcap_handler_data { 96 char *buffer; 97 int len; 98}; 99 100static void handler(u_char *data, const struct pcap_pkthdr *header, 101 const u_char *packet) 102{ 103 int len; 104 105 struct pcap_handler_data *hdata = (struct pcap_handler_data *) data; 106 107 len = hdata->len < header->caplen ? hdata->len : header->caplen; 108 memcpy(hdata->buffer, packet, len); 109 hdata->len = len; 110} 111 112int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri) 113{ 114 struct pcap_handler_data hdata = ((struct pcap_handler_data) 115 { .buffer = buffer, 116 .len = len }); 117 int n; 118 119 n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata); 120 if (n < 0) { 121 printk(UM_KERN_ERR "pcap_dispatch failed - %s\n", 122 pcap_geterr(pri->pcap)); 123 return -EIO; 124 } 125 else if (n == 0) 126 return 0; 127 return hdata.len; 128} 129 130const struct net_user_info pcap_user_info = { 131 .init = pcap_user_init, 132 .open = pcap_open, 133 .close = NULL, 134 .remove = pcap_remove, 135 .add_address = NULL, 136 .delete_address = NULL, 137 .mtu = ETH_MAX_PACKET, 138 .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER, 139}; 140