1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <mach.h>
5 
6 static struct
7 {
8 	ulong magic;
9 	int (*fn)(int, Fhdr*);
10 } cracktab[] = {
11 	0x7F454C46,	crackelf,
12 	0xFEEDFACE,	crackmacho,
13 };
14 
15 Fhdr*
16 crackhdr(char *name, int mode)
17 {
18 	uchar buf[4];
19 	ulong magic;
20 	int i, fd;
21 	Fhdr *hdr;
22 
23 	if((fd = open(name, mode)) < 0)
24 		return nil;
25 
26 	if(seek(fd, 0, 0) < 0 || readn(fd, buf, 4) != 4){
27 		close(fd);
28 		return nil;
29 	}
30 
31 	hdr = mallocz(sizeof(Fhdr), 1);
32 	if(hdr == nil){
33 		close(fd);
34 		return nil;
35 	}
36 	hdr->filename = strdup(name);
37 	magic = beload4(buf);
38 	werrstr("magic doesn't match");
39 	for(i=0; i<nelem(cracktab); i++)
40 		if(cracktab[i].magic == magic && seek(fd, 0, 0) == 0 && cracktab[i].fn(fd, hdr) >= 0){
41 			_addhdr(hdr);
42 			return hdr;
43 		}
44 	werrstr("unknown file type: %r");
45 	free(hdr);
46 	close(fd);
47 	return nil;
48 }
49 
50 void
51 uncrackhdr(Fhdr *hdr)
52 {
53 	close(hdr->fd);
54 	_delhdr(hdr);
55 	free(hdr);
56 }
57 
58 int
59 mapfile(Fhdr *fp, ulong base, Map *map, Regs **regs)
60 {
61 	if(fp == nil){
62 		werrstr("no file");
63 		return -1;
64 	}
65 	if(map == nil){
66 		werrstr("no map");
67 		return -1;
68 	}
69 	if(fp->map == nil){
70 		werrstr("cannot load map for this file type");
71 		return -1;
72 	}
73 	return fp->map(fp, base, map, regs);
74 }
75 
76 void
77 unmapfile(Fhdr *fp, Map *map)
78 {
79 	int i;
80 
81 	if(map == nil || fp == nil)
82 		return;
83 
84 	for(i=0; i<map->nseg; i++){
85 		while(i<map->nseg && map->seg[i].fd == fp->fd){
86 			map->nseg--;
87 			memmove(&map->seg[i], &map->seg[i+1], 
88 				(map->nseg-i)*sizeof(map->seg[0]));
89 		}
90 	}
91 }