ref: 07f324fd0ded2e82b83392894c02560f2c66f641
parent: 746e2af0c21b6b9329d553f69d32fc8c79395cf6
author: Mark Harris <mark.hsj@gmail.com>
date: Wed Sep 30 21:54:32 EDT 2015
opusenc: Consistently use large file interfaces Fix potential infinite loop on a specially-crafted input file if "long" is only 32 bits. Also on some systems, including some versions of Windows and 32-bit OS X, fseek() cannot handle large files even if the offset fits within a "long". These issues are addressed by consistently using the fseek/ftell variants that can handle large files, when available, for all input file processing rather than in only one place. Don't try to seek or use the result if ftell() returns an error (e.g. EOVERFLOW). If large file interfaces are not available, handle seeking in chunks rather than wrapping and potentially causing an infinite loop. When reading data until EOF, treat the ftell() value as only an estimate for percent progress; if the file grows, do not discard data after this point.
--- a/src/audio-in.c
+++ b/src/audio-in.c
@@ -42,6 +42,7 @@
# define _FILE_OFFSET_BITS 64
#endif
+#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
@@ -76,6 +77,21 @@
#include "opus_header.h"
#include "flac.h"
+/* Macros for handling potentially large file offsets */
+#if defined WIN32 || defined _WIN32 || defined WIN64 || defined _WIN64
+# define OFF_T __int64
+# define FSEEK _fseeki64
+# define FTELL _ftelli64
+#elif defined HAVE_FSEEKO
+# define OFF_T off_t
+# define FSEEK fseeko
+# define FTELL ftello
+#else
+# define OFF_T long
+# define FSEEK fseek
+# define FTELL ftell
+#endif
+
/* Macros to read header data */
#define READ_U32_LE(buf) \
(((buf)[3]<<24)|((buf)[2]<<16)|((buf)[1]<<8)|((buf)[0]&0xff))
@@ -142,22 +158,32 @@
return NULL;
}
-static int seek_forward(FILE *in, unsigned int length)
+static int seek_forward(FILE *in, ogg_int64_t length)
{- if(fseek(in, length, SEEK_CUR))
+ ogg_int64_t remaining = length;
+ while(remaining > 0)
{- /* Failed. Do it the hard way. */
- unsigned char buf[1024];
- unsigned int seek_needed = length;
- int seeked;
- while(seek_needed > 0)
+ /* When OFF_T is 64 bits, only one seek is needed and the comparison
+ * will always be false. When OFF_T is not large enough, seek LONG_MAX
+ * bytes at a time (the maximum offset that basic fseek() can handle).
+ */
+ OFF_T seekstep = (OFF_T)remaining;
+ if (seekstep != remaining)
+ seekstep = LONG_MAX;
+ if(FSEEK(in, seekstep, SEEK_CUR))
{- seeked = fread(buf, 1, seek_needed>1024?1024:seek_needed, in);
- if(!seeked)
- return 0; /* Couldn't read more, can't read file */
- else
- seek_needed -= seeked;
+ /* Failed to seek; do it by reading. */
+ unsigned char buf[1024];
+ do {+ size_t readstep = remaining > 1024 ? 1024 : (size_t)remaining;
+ readstep = fread(buf, 1, readstep, in);
+ if(!readstep)
+ return 0; /* Couldn't read more, can't read file */
+ remaining -= readstep;
+ } while (remaining);
+ break;
}
+ remaining -= seekstep;
}
return 1;
}
@@ -204,8 +230,8 @@
/* Handle out of order chunks by seeking back to the start
* to retry */
restarted = 1;
- fseek(in, 12, SEEK_SET);
- continue;
+ if(!FSEEK(in, 12, SEEK_SET))
+ continue;
}
fprintf(stderr, _("Warning: Unexpected EOF in AIFF chunk\n"));return 0;
@@ -592,6 +618,7 @@
opt->rate = format.samplerate;
opt->channels = format.channels;
opt->samplesize = validbits;
+ opt->total_samples_per_channel = 0;
wav = malloc(sizeof(wavfile));
wav->f = in;
@@ -601,10 +628,16 @@
wav->channels = format.channels; /* This is in several places. The price
of trying to abstract stuff. */
wav->samplesize = format.samplesize;
+ wav->totalsamples = 0;
- if(len>(format.channels*samplesize*4U) && len<((1U<<31)-65536) && opt->ignorelength!=1) /*Length provided is plausible.*/
+ if(len>(format.channels*samplesize*4U) && len<((1U<<31)-65536) && opt->ignorelength!=1)
{- opt->total_samples_per_channel = len/(format.channels*samplesize);
+ /* Chunk length is plausible. Limit the audio data read to
+ this length so that we do not misinterpret any additional
+ chunks after this as audio. Also use this length to report
+ percent progress. */
+ wav->totalsamples = opt->total_samples_per_channel =
+ len/(format.channels*samplesize);
}
#ifdef WIN32
/*On Mingw/Win32 fseek() returns zero on pipes.*/
@@ -613,37 +646,27 @@
else if (opt->ignorelength==1)
#endif
{- opt->total_samples_per_channel = 0;
+ /* Assume audio data continues until EOF.
+ No percent progress will be reported. */
}
else
{- opus_int64 pos;
- pos = ftell(in);
- if(fseek(in, 0, SEEK_END) == -1)
+ /* Assume audio data continues until EOF.
+ If the stream is seekable and the current file size can
+ be determined, use that to estimate percent progress
+ (opt->total_samples_per_channel), but not to limit the
+ number of samples read (wav->totalsamples). Continue to
+ read until EOF even if the file grows while reading. */
+ OFF_T pos[2];
+ pos[0] = FTELL(in);
+ if(pos[0] >= 0 && !FSEEK(in, 0, SEEK_END))
{- opt->total_samples_per_channel = 0; /* Give up */
+ pos[1] = FTELL(in);
+ FSEEK(in, pos[0], SEEK_SET);
+ if(pos[1] > pos[0])
+ opt->total_samples_per_channel = (pos[1]-pos[0])/(format.channels*samplesize);
}
- else
- {-#if defined WIN32 || defined _WIN32 || defined WIN64 || defined _WIN64
- opt->total_samples_per_channel = _ftelli64(in);
-#elif defined HAVE_FSEEKO
- opt->total_samples_per_channel = ftello(in);
-#else
- opt->total_samples_per_channel = ftell(in);
-#endif
- if(opt->total_samples_per_channel>pos)
- {- opt->total_samples_per_channel = (opt->total_samples_per_channel-pos)/(format.channels*samplesize);
- }
- else
- {- opt->total_samples_per_channel=0;
- }
- fseek(in,pos, SEEK_SET);
- }
}
- wav->totalsamples = opt->total_samples_per_channel;
opt->readdata = (void *)wav;