libmach

src/libmach/crack.c

@@ -0,0 +1,91 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <mach.h>
+
+static struct
+{
+	ulong magic;
+	int (*fn)(int, Fhdr*);
+} cracktab[] = {
+	0x7F454C46,	crackelf,
+	0xFEEDFACE,	crackmacho,
+};
+
+Fhdr*
+crackhdr(char *name, int mode)
+{
+	uchar buf[4];
+	ulong magic;
+	int i, fd;
+	Fhdr *hdr;
+
+	if((fd = open(name, mode)) < 0)
+		return nil;
+
+	if(seek(fd, 0, 0) < 0 || readn(fd, buf, 4) != 4){
+		close(fd);
+		return nil;
+	}
+
+	hdr = mallocz(sizeof(Fhdr), 1);
+	if(hdr == nil){
+		close(fd);
+		return nil;
+	}
+	hdr->filename = strdup(name);
+	magic = beload4(buf);
+	werrstr("magic doesn't match");
+	for(i=0; i<nelem(cracktab); i++)
+		if(cracktab[i].magic == magic && seek(fd, 0, 0) == 0 && cracktab[i].fn(fd, hdr) >= 0){
+			_addhdr(hdr);
+			return hdr;
+		}
+	werrstr("unknown file type: %r");
+	free(hdr);
+	close(fd);
+	return nil;
+}
+
+void
+uncrackhdr(Fhdr *hdr)
+{
+	close(hdr->fd);
+	_delhdr(hdr);
+	free(hdr);
+}
+
+int
+mapfile(Fhdr *fp, ulong base, Map *map, Regs **regs)
+{
+	if(fp == nil){
+		werrstr("no file");
+		return -1;
+	}
+	if(map == nil){
+		werrstr("no map");
+		return -1;
+	}
+	if(fp->map == nil){
+		werrstr("cannot load map for this file type");
+		return -1;
+	}
+	return fp->map(fp, base, map, regs);
+}
+
+void
+unmapfile(Fhdr *fp, Map *map)
+{
+	int i;
+
+	if(map == nil || fp == nil)
+		return;
+
+	for(i=0; i<map->nseg; i++){
+		while(i<map->nseg && map->seg[i].fd == fp->fd){
+			map->nseg--;
+			memmove(&map->seg[i], &map->seg[i+1], 
+				(map->nseg-i)*sizeof(map->seg[0]));
+		}
+	}
+}