const uint8_t* ksmach_imageUUID(const char* const imageName, bool exactMatch)
{
const uint32_t iImg = ksmach_imageNamed(imageName, exactMatch);
if(iImg != UINT32_MAX)
{
const struct mach_header* header = _dyld_get_image_header(iImg);
if(header != NULL)
{
uintptr_t cmdPtr = ksmach_firstCmdAfterHeader(header);
if(cmdPtr != 0)
{
for(uint32_t iCmd = 0;iCmd < header->ncmds; iCmd++)
{
const struct load_command* loadCmd = (struct load_command*)cmdPtr;
if(loadCmd->cmd == LC_UUID)
{
struct uuid_command* uuidCmd = (struct uuid_command*)cmdPtr;
return uuidCmd->uuid;
}
cmdPtr += loadCmd->cmdsize;
}
}
}
}
return NULL;
}
uintptr_t ksbt_segmentBaseOfImageIndex(const uint32_t idx)
{
const struct mach_header* header = _dyld_get_image_header(idx);
// Look for a segment command and return the file image address.
uintptr_t cmdPtr = ksmach_firstCmdAfterHeader(header);
if(cmdPtr == 0)
{
return 0;
}
for(uint32_t i = 0; i < header->ncmds; i++)
{
const struct load_command* loadCmd = (struct load_command*)cmdPtr;
if(loadCmd->cmd == LC_SEGMENT)
{
const struct segment_command* segmentCmd = (struct segment_command*)cmdPtr;
if(strcmp(segmentCmd->segname, SEG_LINKEDIT) == 0)
{
return segmentCmd->vmaddr - segmentCmd->fileoff;
}
}
else if(loadCmd->cmd == LC_SEGMENT_64)
{
const struct segment_command_64* segmentCmd = (struct segment_command_64*)cmdPtr;
if(strcmp(segmentCmd->segname, SEG_LINKEDIT) == 0)
{
return (uintptr_t)(segmentCmd->vmaddr - segmentCmd->fileoff);
}
}
cmdPtr += loadCmd->cmdsize;
}
return 0;
}
uint32_t ksbt_imageIndexContainingAddress(const uintptr_t address)
{
const uint32_t imageCount = _dyld_image_count();
const struct mach_header* header = 0;
for(uint32_t iImg = 0; iImg < imageCount; iImg++)
{
header = _dyld_get_image_header(iImg);
if(header != NULL)
{
// Look for a segment command with this address within its range.
uintptr_t addressWSlide = address - (uintptr_t)_dyld_get_image_vmaddr_slide(iImg);
uintptr_t cmdPtr = ksmach_firstCmdAfterHeader(header);
if(cmdPtr == 0)
{
continue;
}
for(uint32_t iCmd = 0; iCmd < header->ncmds; iCmd++)
{
const struct load_command* loadCmd = (struct load_command*)cmdPtr;
if(loadCmd->cmd == LC_SEGMENT)
{
const struct segment_command* segCmd = (struct segment_command*)cmdPtr;
if(addressWSlide >= segCmd->vmaddr &&
addressWSlide < segCmd->vmaddr + segCmd->vmsize)
{
return iImg;
}
}
else if(loadCmd->cmd == LC_SEGMENT_64)
{
const struct segment_command_64* segCmd = (struct segment_command_64*)cmdPtr;
if(addressWSlide >= segCmd->vmaddr &&
addressWSlide < segCmd->vmaddr + segCmd->vmsize)
{
return iImg;
}
}
cmdPtr += loadCmd->cmdsize;
}
}
}
return UINT_MAX;
}
bool ksbt_dladdr(const uintptr_t address, Dl_info* const info)
{
info->dli_fname = NULL;
info->dli_fbase = NULL;
info->dli_sname = NULL;
info->dli_saddr = NULL;
const uint32_t idx = ksbt_imageIndexContainingAddress(address);
if(idx == UINT_MAX)
{
return false;
}
const struct mach_header* header = _dyld_get_image_header(idx);
const uintptr_t imageVMAddrSlide = (uintptr_t)_dyld_get_image_vmaddr_slide(idx);
const uintptr_t addressWithSlide = address - imageVMAddrSlide;
const uintptr_t segmentBase = ksbt_segmentBaseOfImageIndex(idx) + imageVMAddrSlide;
if(segmentBase == 0)
{
return false;
}
info->dli_fname = _dyld_get_image_name(idx);
info->dli_fbase = (void*)header;
// Find symbol tables and get whichever symbol is closest to the address.
const STRUCT_NLIST* bestMatch = NULL;
uintptr_t bestDistance = ULONG_MAX;
uintptr_t cmdPtr = ksmach_firstCmdAfterHeader(header);
if(cmdPtr == 0)
{
return false;
}
for(uint32_t iCmd = 0; iCmd < header->ncmds; iCmd++)
{
const struct load_command* loadCmd = (struct load_command*)cmdPtr;
if(loadCmd->cmd == LC_SYMTAB)
{
const struct symtab_command* symtabCmd = (struct symtab_command*)cmdPtr;
const STRUCT_NLIST* symbolTable = (STRUCT_NLIST*)(segmentBase + symtabCmd->symoff);
const uintptr_t stringTable = segmentBase + symtabCmd->stroff;
for(uint32_t iSym = 0; iSym < symtabCmd->nsyms; iSym++)
{
// If n_value is 0, the symbol refers to an external object.
if(symbolTable[iSym].n_value != 0)
{
uintptr_t symbolBase = symbolTable[iSym].n_value;
uintptr_t currentDistance = addressWithSlide - symbolBase;
if((addressWithSlide >= symbolBase) &&
(currentDistance <= bestDistance))
{
bestMatch = symbolTable + iSym;
bestDistance = currentDistance;
}
}
}
if(bestMatch != NULL)
{
info->dli_saddr = (void*)(bestMatch->n_value + imageVMAddrSlide);
info->dli_sname = (char*)((intptr_t)stringTable + (intptr_t)bestMatch->n_un.n_strx);
if(*info->dli_sname == '_')
{
info->dli_sname++;
}
// This happens if all symbols have been stripped.
if(info->dli_saddr == info->dli_fbase && bestMatch->n_type == 3)
{
info->dli_sname = NULL;
}
break;
}
}
cmdPtr += loadCmd->cmdsize;
}
return true;
}
