shithub: libtags

--- a/examples/readtags.c

+++ b/examples/readtags.c

@@ -33,19 +33,48 @@

 static bool image;

+static const char *

+imagetype(int type)

+{

+	static const char *types[] = {

+		[ITother] = "Other",

+		[IT32x32_file_icon] = "32x32 pixels 'file icon' (PNG only)",

+		[ITother_file_icon] = "Other file icon",

+		[ITcover_front] = "Cover (front)",

+		[ITcover_back] = "Cover (back)",

+		[ITleaflet] = "Leaflet page",

+		[ITmedia] = "Media (e.g. label side of CD)",

+		[ITlead] = "Lead artist/lead performer/soloist",

+		[ITartist] = "Artist/performer",

+		[ITconductor] = "Conductor",

+		[ITband] = "Band/orchestra",

+		[ITcomposer] = "Composer",

+		[ITlyricist] = "Lyricist/text writer",

+		[ITlocation] = "Recording location",

+		[ITrecording] = "During recording",

+		[ITperformance] = "During performance",

+		[ITmovie_capture] = "Movie/video screen capture",

+		[ITfish] = "A bright coloured fish",

+		[ITillustration] = "Illustration",

+		[ITlogo_band] = "Band/artist logotype",

+		[ITlogo_publisher] = "Publisher/studio logotype",

+	};

+	return type >= 0 && type < ITnum ? types[type] : "???";

+}

 static void

-tag(Tagctx *ctx, int t, const char *k, const char *v, int offset, int size, Tagread f)

+tag(Tagctx *ctx, int type, Tag *tag)

-	USED(k); USED(f);

 	if(image){

-		if(t != Timage)

+		if(type != Timage)

 			return;

+		int size = tag->image.size;

 		char *raw = malloc(size);

 		Aux *aux = ctx->aux;

 		int prevoffset = lseek(aux->fd, 0, 1);

-		if(lseek(aux->fd, offset, 0) != offset ||

+		if(lseek(aux->fd, tag->image.offset, 0) != tag->image.offset ||

 		   read(aux->fd, raw, size) != size ||

-		   (f != NULL && f(raw, &size) != 0)){

+		   (tag->image.decode != NULL && tag->image.decode(raw, &size) != 0)){

 			fprintf(stderr, "failed to read the image\n");

 			exit(1);

@@ -54,12 +83,10 @@

 		exit(0);

 		return;

-	if(t == Timage)

-		printf("%-12s %s %d %d\n", t2s[t], v, offset, size);

-	else if(t == Tunknown)

-		printf("%-12s %s\n", k, v);

+	if(type == Timage)

+		printf("%-12s %s %d %d (%s)\n", t2s[type], tag->image.mime, tag->image.offset, tag->image.size, imagetype(tag->image.type));

 	else

-		printf("%-12s %s\n", t2s[t], v);

+		printf("%-12s %s\n", type == Tunknown ? tag->text.k : t2s[type], tag->text.v);

 static void

@@ -118,7 +145,6 @@

 		else{

 			if(tagsget(&ctx) != 0){

 				fprintf(stderr, "no tags or failed to read tags\n");

-				return 1;

 			}else if(image){

 				fprintf(stderr, "no images found\n");

 				return 1;

--- a/flac.c

+++ b/flac.c

@@ -7,7 +7,7 @@

 tagflac(Tagctx *ctx)

 	uint8_t *d;

-	int sz, last;

+	int sz, last, type;

 	uint64_t g;

 	d = (uint8_t*)ctx->buf;

@@ -44,7 +44,8 @@

 			if(sz < 8+4+20 || ctx->read(ctx, d, 8) != 8) /* type, mime length */

 				return -1;

 			sz -= 8;

-			n = beuint(&d[4]);

+			type = beuint(d); /* type */

+			n = beuint(&d[4]); /* mime length */

 			mime = ctx->buf+20;

 			if(n < 0 || n >= sz-4-20 || n >= ctx->bufsz-20 || ctx->read(ctx, mime, n) != n)

 				return -1;

@@ -57,8 +58,14 @@

 			sz -= 20;

 			if((n = beuint(&d[16])) < 0)

 				return -1;

-			if(n > 0)

-				tagscallcb(ctx, Timage, "", mime, offset, n, nil);

+			if(n > 0){

+				tagscallcb(ctx, Timage, &(Tag){.image = {

+					.mime = mime,

+					.offset = offset,

+					.size = n,

+					.type = type,

+				}});

+			}

 			if(ctx->seek(ctx, sz, 1) <= 0)

 				return -1;

 		}else if((d[0] & 0x7f) == 4){ /* 4 = vorbis comment */

--- a/harness.c

+++ b/harness.c

@@ -1,6 +1,7 @@

 #include <assert.h>

 #include <stdint.h>

 #include <stdio.h>

+#include <stdlib.h>

 #include <string.h>

 #include <unistd.h>

 #include "tags.h"

@@ -28,9 +29,22 @@

 __AFL_FUZZ_INIT()

 static void

-tag(Tagctx *ctx, int t, const char *k, const char *v, int offset, int size, Tagread f)

+tag(Tagctx *ctx, int t, Tag *tag)

-	USED(ctx); USED(t);  USED(k); USED(v); USED(offset); USED(size); USED(f);

+	if(t == Timage){

+		static uint8_t *buf;

+		static int bufsz;

+		int size = tag->image.size;

+		if(bufsz < size){

+			buf = realloc(buf, size);

+			bufsz = size;

+		}

+		Aux *aux = ctx->aux;

+		memcpy(buf, aux->in+tag->image.offset, size);

+		if(tag->image.decode != NULL)

+			tag->image.decode(buf, &size);

+		assert(size >= 0 && size <= bufsz);

+	}

 static void

--- a/id3v2.c

+++ b/id3v2.c

@@ -159,11 +159,11 @@

 	int n, offset;

 	char *b, *tag;

-	Tagread f;

+	Tagdecode decf;

 	tag = ctx->buf;

 	n = 0;

-	f = unsync ? unsyncread : nil;

+	decf = unsync ? unsyncread : nil;

 	if(strcmp((char*)d, "APIC") == 0){

 		offset = ctx->seek(ctx, 0, 1);

 		if((n = ctx->read(ctx, tag, 255)) == 255){ /* APIC mime and description should fit */

@@ -180,12 +180,20 @@

 					break;

-			tagscallcb(ctx, Timage, "APIC", b, offset+n, tsz-n, f);

-			n = 256;

+			if(tsz > n){

+				tagscallcb(ctx, Timage, &(Tag){.image = {

+					.type = b[strlen(b)+1],

+					.mime = b,

+					.offset = offset+n,

+					.size = tsz-n,

+					.decode = decf,

+				}});

+			}

+			n = 255;

 	}else if(strcmp((char*)d, "PIC") == 0){

 		offset = ctx->seek(ctx, 0, 1);

-		if((n = ctx->read(ctx, tag, 256)) == 256){ /* PIC description should fit */

+		if((n = ctx->read(ctx, tag, 255)) == 255){ /* PIC description should fit */

 			b = tag + 1; /* mime type */

 			for(n = 5; n < 253; n++){

 				if(tag[0] == 0 || tag[0] == 3){ /* one zero byte */

@@ -198,9 +206,16 @@

 					break;

-			if(tsz > n)

-				tagscallcb(ctx, Timage, "PIC", strcmp(b, "JPG") == 0 ? "image/jpeg" : "image/png", offset+n, tsz-n, f);

-			n = 256;

+			if(tsz > n){

+				tagscallcb(ctx, Timage, &(Tag){.image = {

+					.type = b[strlen(b)+1],

+					.mime = strcmp(b, "JPG") == 0 ? "image/jpeg" : "image/png",

+					.offset = offset+n,

+					.size = tsz-n,

+					.decode = decf,

+				}});

+			}

+			n = 255;

 	}else if(strcmp((char*)d, "RVA2") == 0 && tsz >= 6+5){

 		/* replay gain. 6 = "track\0", 5 = other */

--- a/m4a.c

+++ b/m4a.c

@@ -186,10 +186,16 @@

 			d[sz] = 0;

 			txtcb(ctx, type, "", d);

 			sz = 0;

-		}else if(type == Timage && dtype == 13) /* jpeg cover image */

-			tagscallcb(ctx, Timage, "", "image/jpeg", ctx->seek(ctx, 0, 1), sz, nil);

-		else if(type == Timage && dtype == 14) /* png cover image */

-			tagscallcb(ctx, Timage, "", "image/png", ctx->seek(ctx, 0, 1), sz, nil);

+		}else if(type == Timage){

+			tagscallcb(ctx, Timage, &(Tag){.image = {

+				.mime = dtype == 13 ?

+					"image/jpeg" :

+					(dtype == 14 ? "image/png" : ""),

+				.type = ITcover_front,

+				.offset = ctx->seek(ctx, 0, 1),

+				.size = sz,

+			}});

+		}

 	return 0;

--- a/tags.c

+++ b/tags.c

@@ -24,25 +24,24 @@

};

 void

-tagscallcb(Tagctx *ctx, int type, const char *k, char *s, int offset, int size, Tagread f)

+tagscallcb(Tagctx *ctx, int type, Tag *tag)

-	char *e;

+	char *s, *e;

-	if(f == nil && size == 0){

-		while((uint8_t)*s <= ' ' && *s)

-			s++;

+	if(type != Timage){

+		for(s = tag->text.v; (uint8_t)*s <= ' ' && *s; s++);

 		e = s + strlen(s);

 		while(e != s && (uint8_t)e[-1] <= ' ')

 			e--;

 		if(*e != 0)

-		  *e = 0;

+			*e = 0;

+		if(*s == 0)

+			return;

+		tag->text.v = s;

-	if(*s){

-		ctx->tag(ctx, type, k, s, offset, size, f);

-		if(type != Tunknown){

-			ctx->found |= 1<<type;

-		}

-	}

+	ctx->tag(ctx, type, tag);

+	if(type != Tunknown)

+		ctx->found |= 1<<type;

int

--- a/tags.h

+++ b/tags.h

@@ -4,8 +4,9 @@

 extern "C" {

 #endif

+typedef union Tag Tag;

 typedef struct Tagctx Tagctx;

-typedef int (*Tagread)(void *buf, int *cnt);

+typedef int (*Tagdecode)(void *buf, int *cnt);

 /* Tag type. */

 enum {

@@ -54,6 +55,57 @@

 	Fogg __attribute__((deprecated("use Fvorbis instead"))) = Fvorbis,

};

+/* Image types, according to id3v2. */

+enum {

+	ITother,

+	IT32x32_file_icon,

+	ITother_file_icon,

+	ITcover_front,

+	ITcover_back,

+	ITleaflet,

+	ITmedia,

+	ITlead,

+	ITartist,

+	ITconductor,

+	ITband,

+	ITcomposer,

+	ITlyricist,

+	ITlocation,

+	ITrecording,

+	ITperformance,

+	ITmovie_capture,

+	ITfish,

+	ITillustration,

+	ITlogo_band,

+	ITlogo_publisher,

+	ITnum,

+};

+/* Tag itself, either text or image, depending on the "type" passed to the tag callback. */

+union Tag {

+	/* Any tag type except Timage */

+	struct {

+		char *k; /* "TPE1", "replaygain_album_peak" etc */

+		char *v; /* value */

+	}text;

+	/* Tag type Timage */

+	struct {

+		/* If not NULL, reading the image cover requires additional decoding of the data.

+		 * In that case you will need to read the raw data (specified by "offset" and "size")

+		 * and call this function on the buffer (tag->decode(offset, &size)).

+		 * "Size" will be updated with the actual image size after decoding if the function

+		 * returned 0, else there was an error.

+		 */

+		Tagdecode decode;

+		const char *mime; /* "image/png", "image/jpeg" etc */

+		int offset; /* offset from the beginning of the file */

+		int size; /* number of bytes occupied by the raw image data (not decoded) */

+		int type; /* type of the image (ITcover_front, ...) */

+	}image;

+};

 /* Tag parser context. You need to set it properly before parsing an audio file using libtags. */

 struct Tagctx {

 	/* Read function. This is what libtags uses to read the file. */

@@ -63,19 +115,16 @@

 	int (*seek)(Tagctx *ctx, int offset, int whence);

 	/* Callback that is used by libtags to inform about the tags of a file.

-	 * "type" is the tag's type (Tartist, ...) or Tunknown if libtags doesn't know how to map a tag kind to

-	 * any of these. "k" is the raw key like "TPE1", "TPE2", etc. "s" is the null-terminated string unless "type" is

-	 * Timage. "offset" and "size" define the placement and size of the image cover ("type" = Timage)

-	 * inside the file, and "f" is not NULL in case reading the image cover requires additional

-	 * operations on the data, in which case you need to read the image cover as a stream and call this

-	 * function to apply these operations on the contents read.

+	 * "type" is the tag's type (Tartist, ...) or Tunknown if libtags doesn't

+	 * know how to map a tag kind to any of these.

+	 * ANY tag type that isn't Timage is considered a text tag.

*/

-	void (*tag)(Tagctx *ctx, int type, const char *k, const char *s, int offset, int size, Tagread f);

+	void (*tag)(Tagctx *ctx, int type, Tag *tag);

 	/* Approximate millisecond-to-byte offsets within the file, if available. This callback is optional. */

 	void (*toc)(Tagctx *ctx, int ms, int offset);

-	/* Auxiliary data. Not used by libtags. */

+	/* Auxiliary data. Not used by libtags, left for the library user. */

 	void *aux;

 	/* Memory buffer to work in. */

--- a/tagspriv.h

+++ b/tagspriv.h

@@ -65,11 +65,12 @@

/*

  * METADATA_BLOCK_PICTURE reader function.

*/

-int mbpdec(void *buf, int *cnt);

+int cbmbp(Tagctx *ctx, char *v, int ssz, int off, int picsz);

-void tagscallcb(Tagctx *ctx, int type, const char *k, char *s, int offset, int size, Tagread f);

+void tagscallcb(Tagctx *ctx, int type, Tag *tag);

-#define txtcb(ctx, type, k, s) tagscallcb(ctx, type, k, (char*)s, 0, 0, nil)

+#define txtcb(ctx, type, k_, v_) \

+	tagscallcb(ctx, type, &(Tag){.text = {.k = (k_), .v = (char*)(v_)}})

 int tagflac(Tagctx *ctx);

 int tagid3v1(Tagctx *ctx);

--- a/vorbis.c

+++ b/vorbis.c

@@ -43,7 +43,7 @@

 		txtcb(ctx, Tunknown, k, v);

-int

+static int

 mbpdec(void *buf, int *cnt)

 	int sz, n;

@@ -53,7 +53,7 @@

 	if((n = debase64(v, *cnt, v, *cnt)) <= 0)

 		return -1;

-	beuint(v); /* id3v2 APIC type */

+	/* skip id3v2 APIC type */

 	v += 4; n -= 4;

 	sz = beuint(v); /* mime size */

 	v += 4; n -= 4;

@@ -77,11 +77,48 @@

int

+cbmbp(Tagctx *ctx, char *v, int ssz, int off, int picsz)

+{

+	char *mime;

+	int type, n, sz;

+	n = ssz; /* at most this amount is available */

+	n &= ~3; /* modulo 4 sextets, so debase64 gets complete bytes */

+	n = debase64((uint8_t*)v, n, (uint8_t*)ctx->buf, ctx->bufsz);

+	/* https://xiph.org/flac/format.html#metadata_block_picture */

+	if(n <= 4+4+0+4+0+4+4+4+4+4+0)

+		return 0;

+	v = ctx->buf;

+	type = beuint(v); /* id3v2 APIC type */

+	v += 4; n -= 4;

+	sz = beuint(v); /* mime size */

+	v += 4; n -= 4;

+	if(sz < 0 || sz >= n-4-4-4-4-4-4)

+		return -1;

+	mime = v;

+	v += sz; n -= sz; /* skip MIME */

+	sz = beuint(v); /* description size */

+	v += 4; n -= 4;

+	if(sz < 0 || sz >= n-4-4-4-4-4)

+		return -1;

+	*v = 0; /* null-terminate MIME */

+	tagscallcb(ctx, Timage, &(Tag){.image = {

+		.mime = mime,

+		.offset = off,

+		.size = picsz,

+		.type = type,

+		.decode = mbpdec,

+	}});

+	return 0;

+}

+int

 tagvorbis(Tagctx *ctx)

-	char *v, *mime;

+	char *v;

 	uint8_t *d, h[4];

-	int sz, picsz, numtags, i, npages, pgend, skip, off, n;

+	int sz, numtags, i, npages, pgend, skip;

 	d = (uint8_t*)ctx->buf;

 	/* need to find vorbis frame with type=3 */

@@ -148,32 +185,13 @@

 			*v++ = 0;

 			if(strcasecmp(ctx->buf, "metadata_block_picture") != 0)

 				cbvorbiscomment(ctx, ctx->buf, v);

-			else{

-				/* off and picsz will point at the base64-encoded picture block */

-				off = ctx->seek(ctx, 0, 1) - sz + (v - ctx->buf);

-				picsz = sz + skip - (v - ctx->buf);

-				n = sz - (v - ctx->buf); /* at most this amount is available */

-				n &= ~3; /* modulo 4 sextets, so debase64 gets complete bytes */

-				n = debase64((uint8_t*)v, n, (uint8_t*)ctx->buf, ctx->bufsz);

-				/* https://xiph.org/flac/format.html#metadata_block_picture */

-				if(n > 4+4+0+4+0+4+4+4+4+4+0){

-					v = ctx->buf;

-					beuint(v); /* id3v2 APIC type */

-					v += 4; n -= 4;

-					sz = beuint(v); /* mime size */

-					v += 4; n -= 4;

-					if(sz < 0 || sz >= n-4-4-4-4-4-4)

-						return -1;

-					mime = v;

-					v += sz; n -= sz; /* skip MIME */

-					sz = beuint(v); /* description size */

-					v += 4; n -= 4;

-					if(sz < 0 || sz >= n-4-4-4-4-4)

-						return -1;

-					*v = 0; /* null-terminate MIME */

-					tagscallcb(ctx, Timage, "", mime, off, picsz, mbpdec);

-				}

-			}

+			else if(cbmbp(ctx, v,

+					sz - (v - ctx->buf), /* at most this amount is available */

+					ctx->seek(ctx, 0, 1) - sz + (v - ctx->buf), /* offset */

+					sz + skip - (v - ctx->buf) /* total pic size (still encoded) */

+					) != 0)

+				return -1;

 			if(ctx->seek(ctx, skip, 1) < 0)

 				return -1;