1207753Smm/////////////////////////////////////////////////////////////////////////////// 2207753Smm// 3207753Smm/// \file auto_decoder.c 4207753Smm/// \brief Autodetect between .xz Stream and .lzma (LZMA_Alone) formats 5207753Smm// 6207753Smm// Author: Lasse Collin 7207753Smm// 8207753Smm// This file has been put into the public domain. 9207753Smm// You can do whatever you want with this file. 10207753Smm// 11207753Smm/////////////////////////////////////////////////////////////////////////////// 12207753Smm 13207753Smm#include "stream_decoder.h" 14207753Smm#include "alone_decoder.h" 15207753Smm 16207753Smm 17312517Sdelphijtypedef struct { 18207753Smm /// Stream decoder or LZMA_Alone decoder 19207753Smm lzma_next_coder next; 20207753Smm 21207753Smm uint64_t memlimit; 22207753Smm uint32_t flags; 23207753Smm 24207753Smm enum { 25207753Smm SEQ_INIT, 26207753Smm SEQ_CODE, 27207753Smm SEQ_FINISH, 28207753Smm } sequence; 29312517Sdelphij} lzma_auto_coder; 30207753Smm 31207753Smm 32207753Smmstatic lzma_ret 33312517Sdelphijauto_decode(void *coder_ptr, const lzma_allocator *allocator, 34207753Smm const uint8_t *restrict in, size_t *restrict in_pos, 35207753Smm size_t in_size, uint8_t *restrict out, 36207753Smm size_t *restrict out_pos, size_t out_size, lzma_action action) 37207753Smm{ 38312517Sdelphij lzma_auto_coder *coder = coder_ptr; 39312517Sdelphij 40207753Smm switch (coder->sequence) { 41207753Smm case SEQ_INIT: 42207753Smm if (*in_pos >= in_size) 43207753Smm return LZMA_OK; 44207753Smm 45207753Smm // Update the sequence now, because we want to continue from 46207753Smm // SEQ_CODE even if we return some LZMA_*_CHECK. 47207753Smm coder->sequence = SEQ_CODE; 48207753Smm 49207753Smm // Detect the file format. For now this is simple, since if 50207753Smm // it doesn't start with 0xFD (the first magic byte of the 51207753Smm // new format), it has to be LZMA_Alone, or something that 52207753Smm // we don't support at all. 53207753Smm if (in[*in_pos] == 0xFD) { 54207753Smm return_if_error(lzma_stream_decoder_init( 55207753Smm &coder->next, allocator, 56207753Smm coder->memlimit, coder->flags)); 57207753Smm } else { 58207753Smm return_if_error(lzma_alone_decoder_init(&coder->next, 59262754Sdelphij allocator, coder->memlimit, true)); 60207753Smm 61207753Smm // If the application wants to know about missing 62207753Smm // integrity check or about the check in general, we 63207753Smm // need to handle it here, because LZMA_Alone decoder 64207753Smm // doesn't accept any flags. 65207753Smm if (coder->flags & LZMA_TELL_NO_CHECK) 66207753Smm return LZMA_NO_CHECK; 67207753Smm 68207753Smm if (coder->flags & LZMA_TELL_ANY_CHECK) 69207753Smm return LZMA_GET_CHECK; 70207753Smm } 71207753Smm 72207753Smm // Fall through 73207753Smm 74207753Smm case SEQ_CODE: { 75207753Smm const lzma_ret ret = coder->next.code( 76207753Smm coder->next.coder, allocator, 77207753Smm in, in_pos, in_size, 78207753Smm out, out_pos, out_size, action); 79207753Smm if (ret != LZMA_STREAM_END 80207753Smm || (coder->flags & LZMA_CONCATENATED) == 0) 81207753Smm return ret; 82207753Smm 83207753Smm coder->sequence = SEQ_FINISH; 84207753Smm } 85207753Smm 86207753Smm // Fall through 87207753Smm 88207753Smm case SEQ_FINISH: 89207753Smm // When LZMA_DECODE_CONCATENATED was used and we were decoding 90207753Smm // LZMA_Alone file, we need to check check that there is no 91207753Smm // trailing garbage and wait for LZMA_FINISH. 92207753Smm if (*in_pos < in_size) 93207753Smm return LZMA_DATA_ERROR; 94207753Smm 95207753Smm return action == LZMA_FINISH ? LZMA_STREAM_END : LZMA_OK; 96207753Smm 97207753Smm default: 98207753Smm assert(0); 99207753Smm return LZMA_PROG_ERROR; 100207753Smm } 101207753Smm} 102207753Smm 103207753Smm 104207753Smmstatic void 105312517Sdelphijauto_decoder_end(void *coder_ptr, const lzma_allocator *allocator) 106207753Smm{ 107312517Sdelphij lzma_auto_coder *coder = coder_ptr; 108207753Smm lzma_next_end(&coder->next, allocator); 109207753Smm lzma_free(coder, allocator); 110207753Smm return; 111207753Smm} 112207753Smm 113207753Smm 114207753Smmstatic lzma_check 115312517Sdelphijauto_decoder_get_check(const void *coder_ptr) 116207753Smm{ 117312517Sdelphij const lzma_auto_coder *coder = coder_ptr; 118312517Sdelphij 119207753Smm // It is LZMA_Alone if get_check is NULL. 120207753Smm return coder->next.get_check == NULL ? LZMA_CHECK_NONE 121207753Smm : coder->next.get_check(coder->next.coder); 122207753Smm} 123207753Smm 124207753Smm 125207753Smmstatic lzma_ret 126312517Sdelphijauto_decoder_memconfig(void *coder_ptr, uint64_t *memusage, 127207753Smm uint64_t *old_memlimit, uint64_t new_memlimit) 128207753Smm{ 129312517Sdelphij lzma_auto_coder *coder = coder_ptr; 130312517Sdelphij 131207753Smm lzma_ret ret; 132207753Smm 133207753Smm if (coder->next.memconfig != NULL) { 134207753Smm ret = coder->next.memconfig(coder->next.coder, 135207753Smm memusage, old_memlimit, new_memlimit); 136207753Smm assert(*old_memlimit == coder->memlimit); 137207753Smm } else { 138207753Smm // No coder is configured yet. Use the base value as 139207753Smm // the current memory usage. 140207753Smm *memusage = LZMA_MEMUSAGE_BASE; 141207753Smm *old_memlimit = coder->memlimit; 142334607Sdelphij 143207753Smm ret = LZMA_OK; 144334607Sdelphij if (new_memlimit != 0 && new_memlimit < *memusage) 145334607Sdelphij ret = LZMA_MEMLIMIT_ERROR; 146207753Smm } 147207753Smm 148207753Smm if (ret == LZMA_OK && new_memlimit != 0) 149207753Smm coder->memlimit = new_memlimit; 150207753Smm 151207753Smm return ret; 152207753Smm} 153207753Smm 154207753Smm 155207753Smmstatic lzma_ret 156278433Srpauloauto_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator, 157207753Smm uint64_t memlimit, uint32_t flags) 158207753Smm{ 159207753Smm lzma_next_coder_init(&auto_decoder_init, next, allocator); 160207753Smm 161207753Smm if (flags & ~LZMA_SUPPORTED_FLAGS) 162207753Smm return LZMA_OPTIONS_ERROR; 163207753Smm 164312517Sdelphij lzma_auto_coder *coder = next->coder; 165312517Sdelphij if (coder == NULL) { 166312517Sdelphij coder = lzma_alloc(sizeof(lzma_auto_coder), allocator); 167312517Sdelphij if (coder == NULL) 168207753Smm return LZMA_MEM_ERROR; 169207753Smm 170312517Sdelphij next->coder = coder; 171207753Smm next->code = &auto_decode; 172207753Smm next->end = &auto_decoder_end; 173207753Smm next->get_check = &auto_decoder_get_check; 174207753Smm next->memconfig = &auto_decoder_memconfig; 175312517Sdelphij coder->next = LZMA_NEXT_CODER_INIT; 176207753Smm } 177207753Smm 178334607Sdelphij coder->memlimit = my_max(1, memlimit); 179312517Sdelphij coder->flags = flags; 180312517Sdelphij coder->sequence = SEQ_INIT; 181207753Smm 182207753Smm return LZMA_OK; 183207753Smm} 184207753Smm 185207753Smm 186207753Smmextern LZMA_API(lzma_ret) 187207753Smmlzma_auto_decoder(lzma_stream *strm, uint64_t memlimit, uint32_t flags) 188207753Smm{ 189207753Smm lzma_next_strm_init(auto_decoder_init, strm, memlimit, flags); 190207753Smm 191207753Smm strm->internal->supported_actions[LZMA_RUN] = true; 192207753Smm strm->internal->supported_actions[LZMA_FINISH] = true; 193207753Smm 194207753Smm return LZMA_OK; 195207753Smm} 196