static int
read_macho(
int fd,
struct mach_header *the_header,
struct load_command ***the_commands,
unsigned *the_commands_len
)
{
struct load_command command;
struct load_command *buf;
int i;
int size;
if (read(fd, the_header, sizeof(*the_header)) != sizeof(*the_header)) {
fatal_unexec("cannot read macho header");
return (0);
}
/* the mach header should already be in native form */
if (the_header->magic != MH_MAGIC) {
fatal_unexec("wrong magic in macho header");
}
for (i = 0; i < the_header->ncmds; i++) {
if (read(fd, &command, sizeof(struct load_command)) !=
sizeof(struct load_command)) {
fatal_unexec("cannot read macho load command header");
return (0);
}
size = command.cmdsize - sizeof(struct load_command);
if (size < 0) {
fatal_unexec("bogus load command size");
return (0);
}
buf = malloc(command.cmdsize);
buf->cmd = command.cmd;
buf->cmdsize = command.cmdsize;
if (read(fd, ((char *)buf +
sizeof(struct load_command)),
size) != size) {
fatal_unexec("cannot read load command data");
return (0);
}
save_command(buf, the_commands, the_commands_len);
}
/* Leave the file pointer at the beginning of the text segment */
return (1);
}
static void mcopy(int ffd,int tfd,
unsigned long fpos,unsigned long tpos,unsigned long len)
{
if ((ffd==-1)&&(tfd==-1))
{
char *f,*t,*e;
if (fpos>tpos)
{
f=(char *)fpos;
t=(char *)tpos;
e=(char *)(fpos+len);
while(f<e) *t++=*f++;
}
else if (tpos>fpos)
{
f=(char *)(fpos+len);
t=(char *)(tpos+len);
e=(char *)fpos;
while(f>e) *--t=*--f;
}
}
else if (ffd==-1)
{
if (lseek(tfd,tpos,L_SET)<0)
fatal_unexec("cannot seek target");
if (write(tfd,(void *)fpos,len)!=len)
fatal_unexec("cannot write target");
}
else if (tfd==-1)
{
if (lseek(ffd,fpos,L_SET)<0)
fatal_unexec("cannot seek source");
if (read(ffd,(void *)tpos,len)!=len)
fatal_unexec("cannot read source");
}
else
{
int bread;
char *buf=alloca(1<<16);
if (lseek(ffd,fpos,L_SET)<0)
fatal_unexec("cannot seek source");
if (lseek(tfd,tpos,L_SET)<0)
fatal_unexec("cannot seek target");
while((len>0) && (bread=read(ffd,buf,MIN(1<<16,len)))>0)
{
if (bread<0)
fatal_unexec("cannot read source");
if (write(tfd,buf,bread)!=bread)
fatal_unexec("cannot write target");
len-=bread;
}
}
}
void
unexec(
char *outfile,
char *infile
)
{
int infd;
int outfd;
char tmpbuf[L_tmpnam];
char *tmpfile;
infd = open(infile, O_RDONLY, 0);
if (infd < 0) {
fatal_unexec("cannot open input file `%s'", infile);
exit(1);
}
tmpnam(tmpbuf);
tmpfile = rindex(tmpbuf, '/');
if (tmpfile == NULL) {
tmpfile = tmpbuf;
} else {
tmpfile++;
}
outfd = open(tmpfile, O_WRONLY|O_TRUNC|O_CREAT, 0755);
if (outfd < 0) {
close(infd);
fatal_unexec("cannot open tmp file `%s'", tmpfile);
exit(1);
}
if (!unexec_doit(infd, outfd)) {
close(infd);
close(outfd);
unlink(tmpfile);
exit(1);
}
close(infd);
close(outfd);
if (rename(tmpfile, outfile) < 0) {
unlink(tmpfile);
fatal_unexec("cannot rename `%s' to `%s'", tmpfile, outfile);
exit(1);
}
}
static int
read_macho(
int fd,
struct mach_header *the_header,
struct load_command ***the_commands,
unsigned *the_commands_len
)
{
struct load_command command;
struct load_command *buf;
int i;
int size;
if (read(fd, the_header, sizeof(*the_header)) != sizeof(*the_header)) {
fatal_unexec("cannot read macho header");
return (0);
}
for (i = 0; i < the_header->ncmds; i++) {
if (read(fd, &command, sizeof(struct load_command)) !=
sizeof(struct load_command)) {
fatal_unexec("cannot read macho load command header");
return (0);
}
size = command.cmdsize - sizeof(struct load_command);
if (size < 0) {
fatal_unexec("bogus load command size");
return (0);
}
buf = malloc(command.cmdsize);
buf->cmd = command.cmd;
buf->cmdsize = command.cmdsize;
if (read(fd, ((char *)buf +
sizeof(struct load_command)),
size) != size) {
fatal_unexec("cannot read load command data");
return (0);
}
save_command(buf, the_commands, the_commands_len);
}
return (1);
}
void unexec(char *outfile,char *infile)
{
char tmpfile[MAXPATHLEN];
int infd,outfd;
if ((infd=open(infile, O_RDONLY, 0))<0)
fatal_unexec("cannot open input file `%s'", infile);
strcpy(tmpfile,outfile);
strcat(tmpfile,"-temp");
if ((outfd=open(tmpfile, O_RDWR|O_TRUNC|O_CREAT, 0755))<0)
fatal_unexec("cannot open temporary output file `%s'",tmpfile);
unexec_doit(infd,outfd);
close(infd);
close(outfd);
if (rename(tmpfile, outfile)<0)
{
unlink(tmpfile);
fatal_unexec("cannot rename `%s' to `%s'", tmpfile, outfile);
}
}
static int
filldatagap(
vm_address_t start_address,
vm_size_t *size,
vm_address_t end_address
)
{
vm_address_t address;
vm_size_t gapsize;
address = (start_address + *size);
gapsize = end_address - address;
*size += gapsize;
if (vm_allocate(task_self(), &address, gapsize,
FALSE) != KERN_SUCCESS) {
fatal_unexec("cannot vm_allocate");
return (0);
}
return (1);
}
static int
unexec_doit(
int infd,
int outfd
)
{
int i;
struct load_command **the_commands = NULL;
unsigned the_commands_len;
struct mach_header the_header;
int fgrowth = 0;
int fdatastart;
int fdatasize;
int size;
struct stat st;
char *buf;
vm_address_t data_address;
vm_size_t data_size;
vm_size_t vmaddr_growth = 0;
vm_size_t dataseg_vmaddr, dataseg_vmend;
struct segment_command *segment;
#ifdef NS_TARGET
unsigned long extreloff = 0;
unsigned long nextrel = 0;
struct dysymtab_command *dysymtab;
struct relocation_info reloc_info;
#endif
if (!read_macho(infd, &the_header, &the_commands, &the_commands_len)) {
return (0);
}
malloc_cookie = malloc_freezedry ();
if (!get_data_region(&data_address, &data_size)) {
return (0);
}
/*
* DO NOT USE MALLOC IN THIS SECTION
*/
{
/*
* Fix offsets
*/
for (i = 0; i < the_commands_len; i++) {
switch (the_commands[i]->cmd) {
case LC_SEGMENT:
segment = ((struct segment_command *)
the_commands[i]);
if (strcmp(segment->segname, SEG_DATA) == 0) {
fdatastart = segment->fileoff;
fdatasize = segment->filesize;
fgrowth = (data_size -
segment->filesize);
segment->vmsize = data_size;
segment->filesize = data_size;
dataseg_vmaddr = segment->vmaddr;
dataseg_vmend = segment->vmaddr + segment->vmsize;
vmaddr_growth = segment->vmaddr + segment->vmsize;
} else {
((struct segment_command *)the_commands[i])->fileoff += fgrowth;
}
if( strcmp( segment->segname, SEG_LINKEDIT ) == 0 ) {
segment->vmaddr = vmaddr_growth;
}
break;
case LC_SYMTAB:
((struct symtab_command *)
the_commands[i])->symoff += fgrowth;
((struct symtab_command *)
the_commands[i])->stroff += fgrowth;
break;
case LC_SYMSEG:
((struct symseg_command *)
the_commands[i])->offset += fgrowth;
break;
#ifdef NS_TARGET
case LC_DYSYMTAB:
dysymtab = ((struct dysymtab_command *)the_commands[i]);
extreloff = dysymtab->extreloff;
nextrel = dysymtab->nextrel;
dysymtab->indirectsymoff += fgrowth;
dysymtab->extreloff += fgrowth;
break;
#endif
default:
break;
}
}
/*
* Write header
*/
if (write(outfd, &the_header,
sizeof(the_header)) != sizeof(the_header)) {
fatal_unexec("cannot write output file");
return (0);
}
/*
* Write commands
*/
for (i = 0; i < the_commands_len; i++) {
if (write(outfd, the_commands[i],
the_commands[i]->cmdsize) !=
the_commands[i]->cmdsize) {
fatal_unexec("cannot write output file");
return (0);
}
}
/*
* Write original text
*/
if (lseek(infd, the_header.sizeofcmds + sizeof(the_header),
L_SET) < 0) {
fatal_unexec("cannot seek input file");
return (0);
}
size = fdatastart - (sizeof(the_header) +
the_header.sizeofcmds);
buf = my_malloc(size);
if (read(infd, buf, size) != size) {
my_free(buf, size);
fatal_unexec("cannot read input file");
}
if (write(outfd, buf, size) != size) {
my_free(buf, size);
fatal_unexec("cannot write output file");
return (0);
}
my_free(buf, size);
/*
* Write new data
*/
if (write(outfd, (char *)data_address,
data_size) != data_size) {
fatal_unexec("cannot write output file");
return (0);
}
}
/*
* OKAY TO USE MALLOC NOW
*/
/*
* Write rest of file
*/
fstat(infd, &st);
if (lseek(infd, fdatasize, L_INCR) < 0) {
fatal_unexec("cannot seek input file");
return (0);
}
size = st.st_size - lseek(infd, 0, L_INCR);
buf = malloc(size);
if (read(infd, buf, size) != size) {
free(buf);
fatal_unexec("cannot read input file");
return (0);
}
if (write(outfd, buf, size) != size) {
free(buf);
fatal_unexec("cannot write output file");
return (0);
}
free(buf);
#ifdef NS_TARGET
/*
* Fix up relocation entries in the data segment.
*/
if (lseek(infd, extreloff, L_SET) < 0) {
fatal_unexec("cannot seek input file");
return (0);
}
for (i = 0; i < nextrel; i++)
{
long zeroval = 0;
if (read(infd, &reloc_info, sizeof (reloc_info)) != sizeof (reloc_info)) {
fatal_unexec("cannot read input file");
return (0);
}
if (reloc_info.r_address >= dataseg_vmaddr && reloc_info.r_address < dataseg_vmend)
{
if (lseek (outfd, fdatastart + reloc_info.r_address - dataseg_vmaddr, L_SET) < 0 ) {
fatal_unexec("cannot seek input file");
return (0);
}
switch (reloc_info.r_length) {
case 0:
if (write(outfd, &zeroval, 1) != 1) {
fatal_unexec("cannot write output file");
return (0);
}
break;
case 1:
if (write(outfd, &zeroval, 2) != 2) {
fatal_unexec("cannot write output file");
return (0);
}
break;
case 2:
if (write(outfd, &zeroval, 4) != 4) {
fatal_unexec("cannot write output file");
return (0);
}
break;
}
}
}
#endif
return (1);
}
static int
unexec_doit(
int infd,
int outfd
)
{
int i;
struct load_command **the_commands = NULL;
unsigned the_commands_len;
struct mach_header the_header;
int fgrowth;
int fdatastart;
int fdatasize;
int size;
struct stat st;
char *buf;
vm_address_t data_address;
vm_size_t data_size;
struct segment_command *segment;
if (!read_macho(infd, &the_header, &the_commands, &the_commands_len)) {
return (0);
}
malloc_cookie = malloc_freezedry();
if (!get_data_region(&data_address, &data_size)) {
return (0);
}
/*
* DO NOT USE MALLOC IN THIS SECTION
*/
{
/*
* Fix offsets
*/
for (i = 0; i < the_commands_len; i++) {
switch (the_commands[i]->cmd) {
case LC_SEGMENT:
segment = ((struct segment_command *)
the_commands[i]);
if (strcmp(segment->segname, SEG_DATA) == 0) {
fdatastart = segment->fileoff;
fdatasize = segment->filesize;
fgrowth = (data_size -
segment->filesize);
segment->vmsize = data_size;
segment->filesize = data_size;
}
break;
case LC_SYMTAB:
((struct symtab_command *)
the_commands[i])->symoff += fgrowth;
((struct symtab_command *)
the_commands[i])->stroff += fgrowth;
break;
case LC_SYMSEG:
((struct symseg_command *)
the_commands[i])->offset += fgrowth;
break;
default:
break;
}
}
/*
* Write header
*/
if (write(outfd, &the_header,
sizeof(the_header)) != sizeof(the_header)) {
fatal_unexec("cannot write output file");
return (0);
}
/*
* Write commands
*/
for (i = 0; i < the_commands_len; i++) {
if (write(outfd, the_commands[i],
the_commands[i]->cmdsize) !=
the_commands[i]->cmdsize) {
fatal_unexec("cannot write output file");
return (0);
}
}
/*
* Write original text
* We're already positioned at the beginning of the text
* segment, so all we need to do is to copy the bytes.
*/
size = fdatastart - (sizeof(the_header) +
the_header.sizeofcmds);
buf = my_malloc(size);
if (read(infd, buf, size) != size) {
my_free(buf, size);
fatal_unexec("cannot read input file");
}
if (write(outfd, buf, size) != size) {
my_free(buf, size);
fatal_unexec("cannot write output file");
return (0);
}
my_free(buf, size);
/*
* Write new data
*/
if (write(outfd, (char *)data_address,
data_size) != data_size) {
fatal_unexec("cannot write output file");
return (0);
}
}
/*
* OKAY TO USE MALLOC NOW
*/
/*
* Write rest of file
*/
fstat(infd, &st);
if (lseek(infd, fdatasize, L_INCR) < 0) {
fatal_unexec("cannot seek input file");
return (0);
}
size = st.st_size - lseek(infd, 0, L_INCR);
buf = malloc(size);
if (read(infd, buf, size) != size) {
free(buf);
fatal_unexec("cannot read input file");
return (0);
}
if (write(outfd, buf, size) != size) {
free(buf);
fatal_unexec("cannot write output file");
return (0);
}
free(buf);
return (1);
}
