1 #include <u.h>
2 #include <libc.h>
3 #include <bio.h>
4 #include <mach.h>
5 #include "elf.h"
6 
7 static struct
8 {
9 	ulong magic;
10 	int (*fn)(int, Fhdr*);
11 } cracktab[] = {
12 	0x7F454C46,	crackelf,
13 	0xFEEDFACE,	crackmacho,
14 };
15 
16 Fhdr*
17 crackhdr(char *name, int mode)
18 {
19 	uchar buf[4];
20 	ulong magic;
21 	int i, fd;
22 	Fhdr *hdr;
23 
24 	if((fd = open(name, mode)) < 0)
25 		return nil;
26 
27 	if(seek(fd, 0, 0) < 0 || readn(fd, buf, 4) != 4){
28 		close(fd);
29 		return nil;
30 	}
31 
32 	hdr = mallocz(sizeof(Fhdr), 1);
33 	if(hdr == nil){
34 		close(fd);
35 		return nil;
36 	}
37 	hdr->filename = strdup(name);
38 	magic = beload4(buf);
39 	werrstr("magic doesn't match");
40 	for(i=0; i<nelem(cracktab); i++)
41 		if(cracktab[i].magic == magic && seek(fd, 0, 0) == 0 && cracktab[i].fn(fd, hdr) >= 0){
42 			_addhdr(hdr);
43 			return hdr;
44 		}
45 	werrstr("unknown file type: %r");
46 	free(hdr);
47 	close(fd);
48 	return nil;
49 }
50 
51 void
52 uncrackhdr(Fhdr *hdr)
53 {
54 	int i;
55 
56 	symclose(hdr);
57 	if(hdr->elf)
58 		elfclose(hdr->elf);
59 	if(hdr->fd >= 0)
60 		close(hdr->fd);
61 	free(hdr->cmdline);
62 	free(hdr->prog);
63 	for(i=0; i<hdr->nthread; i++)
64 		free(hdr->thread[i].ureg);
65 	free(hdr->thread);
66 	free(hdr);
67 }
68 
69 int
70 mapfile(Fhdr *fp, ulong base, Map *map, Regs **regs)
71 {
72 	if(fp == nil){
73 		werrstr("no file");
74 		return -1;
75 	}
76 	if(map == nil){
77 		werrstr("no map");
78 		return -1;
79 	}
80 	if(fp->map == 0){
81 		werrstr("cannot load map for this file type");
82 		return -1;
83 	}
84 	if(regs)
85 		*regs = nil;
86 	return fp->map(fp, base, map, regs);
87 }
88 
89 void
90 unmapfile(Fhdr *fp, Map *map)
91 {
92 	int i;
93 
94 	if(map == nil || fp == nil)
95 		return;
96 
97 	for(i=0; i<map->nseg; i++){
98 		while(i<map->nseg && map->seg[i].fd == fp->fd){
99 			map->nseg--;
100 			memmove(&map->seg[i], &map->seg[i+1], 
101 				(map->nseg-i)*sizeof(map->seg[0]));
102 		}
103 	}
104 }
105 
106 Regs*
107 coreregs(Fhdr *fp, uint id)
108 {
109 	UregRegs *r;
110 	int i;
111 
112 	for(i=0; i<fp->nthread; i++){
113 		if(fp->thread[i].id == id){
114 			if((r = mallocz(sizeof *r, 1)) == nil)
115 				return nil;
116 			r->r.rw = _uregrw;
117 			r->ureg = fp->thread[i].ureg;
118 			return &r->r;
119 		}
120 	}
121 	werrstr("thread not found");
122 	return nil;
123 }
124