xref: /freebsd/sbin/ipf/libipf/kmem.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
1 
2 /*
3  * Copyright (C) 2012 by Darren Reed.
4  *
5  * See the IPFILTER.LICENCE file for details on licencing.
6  */
7 /*
8  * kmemcpy() - copies n bytes from kernel memory into user buffer.
9  * returns 0 on success, -1 on error.
10  */
11 
12 #include <stdio.h>
13 #include <sys/param.h>
14 #include <sys/types.h>
15 #include <sys/uio.h>
16 #include <unistd.h>
17 #include <string.h>
18 #include <fcntl.h>
19 #include <sys/file.h>
20 #include <kvm.h>
21 #include <fcntl.h>
22 #include <sys/socket.h>
23 #include <sys/ioctl.h>
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
26 #include <netinet/in_systm.h>
27 #include <netinet/ip.h>
28 #include <net/if.h>
29 
30 #include "kmem.h"
31 
32 
33 
34 
35 static	kvm_t	*kvm_f = NULL;
36 
37 
38 int
39 openkmem(char *kern, char *core)
40 {
41 	kvm_f = kvm_open(kern, core, NULL, O_RDONLY, NULL);
42 	if (kvm_f == NULL)
43 	    {
44 		perror("openkmem:open");
45 		return (-1);
46 	    }
47 	return (kvm_f != NULL);
48 }
49 
50 int
51 kmemcpy(register char *buf, long pos, register int n)
52 {
53 	register int	r;
54 
55 	if (!n)
56 		return (0);
57 
58 	if (kvm_f == NULL)
59 		if (openkmem(NULL, NULL) == -1)
60 			return (-1);
61 
62 	while ((r = kvm_read(kvm_f, pos, buf, n)) < n)
63 		if (r <= 0)
64 		    {
65 			fprintf(stderr, "pos=0x%lx ", (u_long)pos);
66 			perror("kmemcpy:read");
67 			return (-1);
68 		    }
69 		else
70 		    {
71 			buf += r;
72 			pos += r;
73 			n -= r;
74 		    }
75 	return (0);
76 }
77 
78 int
79 kstrncpy(register char *buf, long pos, register int n)
80 {
81 	register int	r;
82 
83 	if (!n)
84 		return (0);
85 
86 	if (kvm_f == NULL)
87 		if (openkmem(NULL, NULL) == -1)
88 			return (-1);
89 
90 	while (n > 0)
91 	    {
92 		r = kvm_read(kvm_f, pos, buf, 1);
93 		if (r <= 0)
94 		    {
95 			fprintf(stderr, "pos=0x%lx ", (u_long)pos);
96 			perror("kmemcpy:read");
97 			return (-1);
98 		    }
99 		else
100 		    {
101 			if (*buf == '\0')
102 				break;
103 			buf++;
104 			pos++;
105 			n--;
106 		    }
107 	    }
108 	return (0);
109 }
110