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 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 */ 144