1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
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 <um_malloc.h> |
13 | |
14 | #define PCAP_FD(p) (*(int *)(p)) |
15 | |
16 | static int pcap_user_init(void *data, void *dev) |
17 | { |
18 | struct pcap_data *pri = data; |
19 | pcap_t *p; |
20 | char errors[PCAP_ERRBUF_SIZE]; |
21 | |
22 | p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER, |
23 | pri->promisc, 0, errors); |
24 | if (p == NULL) { |
25 | printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - " |
26 | "'%s'\n" , errors); |
27 | return -EINVAL; |
28 | } |
29 | |
30 | pri->dev = dev; |
31 | pri->pcap = p; |
32 | return 0; |
33 | } |
34 | |
35 | static int pcap_user_open(void *data) |
36 | { |
37 | struct pcap_data *pri = data; |
38 | __u32 netmask; |
39 | int err; |
40 | |
41 | if (pri->pcap == NULL) |
42 | return -ENODEV; |
43 | |
44 | if (pri->filter != NULL) { |
45 | err = dev_netmask(pri->dev, &netmask); |
46 | if (err < 0) { |
47 | printk(UM_KERN_ERR "pcap_user_open : dev_netmask failed\n" ); |
48 | return -EIO; |
49 | } |
50 | |
51 | pri->compiled = uml_kmalloc(sizeof(struct bpf_program), |
52 | UM_GFP_KERNEL); |
53 | if (pri->compiled == NULL) { |
54 | printk(UM_KERN_ERR "pcap_user_open : kmalloc failed\n" ); |
55 | return -ENOMEM; |
56 | } |
57 | |
58 | err = pcap_compile(pri->pcap, |
59 | (struct bpf_program *) pri->compiled, |
60 | pri->filter, pri->optimize, netmask); |
61 | if (err < 0) { |
62 | printk(UM_KERN_ERR "pcap_user_open : pcap_compile failed - " |
63 | "'%s'\n" , pcap_geterr(pri->pcap)); |
64 | goto out; |
65 | } |
66 | |
67 | err = pcap_setfilter(pri->pcap, pri->compiled); |
68 | if (err < 0) { |
69 | printk(UM_KERN_ERR "pcap_user_open : pcap_setfilter " |
70 | "failed - '%s'\n" , pcap_geterr(pri->pcap)); |
71 | goto out; |
72 | } |
73 | } |
74 | |
75 | return PCAP_FD(pri->pcap); |
76 | |
77 | out: |
78 | kfree(pri->compiled); |
79 | return -EIO; |
80 | } |
81 | |
82 | static void pcap_remove(void *data) |
83 | { |
84 | struct pcap_data *pri = data; |
85 | |
86 | if (pri->compiled != NULL) |
87 | pcap_freecode(pri->compiled); |
88 | |
89 | if (pri->pcap != NULL) |
90 | pcap_close(pri->pcap); |
91 | } |
92 | |
93 | struct pcap_handler_data { |
94 | char *buffer; |
95 | int len; |
96 | }; |
97 | |
98 | static void handler(u_char *data, const struct pcap_pkthdr *, |
99 | const u_char *packet) |
100 | { |
101 | int len; |
102 | |
103 | struct pcap_handler_data *hdata = (struct pcap_handler_data *) data; |
104 | |
105 | len = hdata->len < header->caplen ? hdata->len : header->caplen; |
106 | memcpy(hdata->buffer, packet, len); |
107 | hdata->len = len; |
108 | } |
109 | |
110 | int pcap_user_read(int fd, void *buffer, int len, struct pcap_data *pri) |
111 | { |
112 | struct pcap_handler_data hdata = ((struct pcap_handler_data) |
113 | { .buffer = buffer, |
114 | .len = len }); |
115 | int n; |
116 | |
117 | n = pcap_dispatch(pri->pcap, 1, handler, (u_char *) &hdata); |
118 | if (n < 0) { |
119 | printk(UM_KERN_ERR "pcap_dispatch failed - %s\n" , |
120 | pcap_geterr(pri->pcap)); |
121 | return -EIO; |
122 | } |
123 | else if (n == 0) |
124 | return 0; |
125 | return hdata.len; |
126 | } |
127 | |
128 | const struct net_user_info pcap_user_info = { |
129 | .init = pcap_user_init, |
130 | .open = pcap_user_open, |
131 | .close = NULL, |
132 | .remove = pcap_remove, |
133 | .add_address = NULL, |
134 | .delete_address = NULL, |
135 | .mtu = ETH_MAX_PACKET, |
136 | .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER, |
137 | }; |
138 | |