X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=inline;f=libbb%2Fread.c;h=b93a695b569f9e6cc2c3d593f94652b79b69868b;hb=fe4e23f9ded69194d525775b1ef7648461a7f76d;hp=1d31fb076618098488938b0e86388e85d6bee773;hpb=8ee649a02e97e9d4e770a8138ba94c0f3ddd8055;p=oweals%2Fbusybox.git

diff --git a/libbb/read.c b/libbb/read.c
index 1d31fb076..b93a695b5 100644
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -9,7 +9,17 @@
 
 #include "libbb.h"
 
-ssize_t safe_read(int fd, void *buf, size_t count)
+#define ZIPPED (ENABLE_FEATURE_SEAMLESS_LZMA \
+	|| ENABLE_FEATURE_SEAMLESS_BZ2 \
+	|| ENABLE_FEATURE_SEAMLESS_GZ \
+	/* || ENABLE_FEATURE_SEAMLESS_Z */ \
+)
+
+#if ZIPPED
+#include "unarchive.h"
+#endif
+
+ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
 {
 	ssize_t n;
 
@@ -56,7 +66,7 @@ ssize_t safe_read(int fd, void *buf, size_t count)
  * which detects EAGAIN and uses poll() to wait on the fd.
  * Thankfully, poll() doesn't care about O_NONBLOCK flag.
  */
-ssize_t nonblock_safe_read(int fd, void *buf, size_t count)
+ssize_t FAST_FUNC nonblock_safe_read(int fd, void *buf, size_t count)
 {
 	struct pollfd pfd[1];
 	ssize_t n;
@@ -78,7 +88,7 @@ ssize_t nonblock_safe_read(int fd, void *buf, size_t count)
  * Returns the amount read, or -1 on an error.
  * A short read is returned on an end of file.
  */
-ssize_t full_read(int fd, void *buf, size_t len)
+ssize_t FAST_FUNC full_read(int fd, void *buf, size_t len)
 {
 	ssize_t cc;
 	ssize_t total;
@@ -106,61 +116,36 @@ ssize_t full_read(int fd, void *buf, size_t len)
 	return total;
 }
 
-// Die with an error message if we can't read the entire buffer.
-void xread(int fd, void *buf, size_t count)
+/* Die with an error message if we can't read the entire buffer. */
+void FAST_FUNC xread(int fd, void *buf, size_t count)
 {
 	if (count) {
 		ssize_t size = full_read(fd, buf, count);
-		if (size != count)
+		if ((size_t)size != count)
 			bb_error_msg_and_die("short read");
 	}
 }
 
-// Die with an error message if we can't read one character.
-unsigned char xread_char(int fd)
+/* Die with an error message if we can't read one character. */
+unsigned char FAST_FUNC xread_char(int fd)
 {
 	char tmp;
 	xread(fd, &tmp, 1);
 	return tmp;
 }
 
-// Read one line a-la fgets. Works only on seekable streams
-char *reads(int fd, char *buffer, size_t size)
-{
-	char *p;
-
-	if (size < 2)
-		return NULL;
-	size = full_read(fd, buffer, size-1);
-	if ((ssize_t)size <= 0)
-		return NULL;
-
-	buffer[size] = '\0';
-	p = strchr(buffer, '\n');
-	if (p) {
-		off_t offset;
-		*p++ = '\0';
-		// avoid incorrect (unsigned) widening
-		offset = (off_t)(p - buffer) - (off_t)size;
-		// set fd position right after '\n'
-		if (offset && lseek(fd, offset, SEEK_CUR) == (off_t)-1)
-			return NULL;
-	}
-	return buffer;
-}
-
 // Reads one line a-la fgets (but doesn't save terminating '\n').
 // Reads byte-by-byte. Useful when it is important to not read ahead.
 // Bytes are appended to pfx (which must be malloced, or NULL).
-char *xmalloc_reads(int fd, char *buf, size_t *maxsz_p)
+char* FAST_FUNC xmalloc_reads(int fd, char *buf, size_t *maxsz_p)
 {
 	char *p;
 	size_t sz = buf ? strlen(buf) : 0;
-	size_t maxsz = maxsz_p ? *maxsz_p : MAXINT(size_t);
+	size_t maxsz = maxsz_p ? *maxsz_p : (INT_MAX - 4095);
 
 	goto jump_in;
 	while (sz < maxsz) {
-		if (p - buf == sz) {
+		if ((size_t)(p - buf) == sz) {
  jump_in:
 			buf = xrealloc(buf, sz + 128);
 			p = buf + sz;
@@ -185,7 +170,7 @@ char *xmalloc_reads(int fd, char *buf, size_t *maxsz_p)
 	return xrealloc(buf, p - buf);
 }
 
-ssize_t read_close(int fd, void *buf, size_t size)
+ssize_t FAST_FUNC read_close(int fd, void *buf, size_t size)
 {
 	/*int e;*/
 	size = full_read(fd, buf, size);
@@ -195,7 +180,7 @@ ssize_t read_close(int fd, void *buf, size_t size)
 	return size;
 }
 
-ssize_t open_read_close(const char *filename, void *buf, size_t size)
+ssize_t FAST_FUNC open_read_close(const char *filename, void *buf, size_t size)
 {
 	int fd = open(filename, O_RDONLY);
 	if (fd < 0)
@@ -203,29 +188,207 @@ ssize_t open_read_close(const char *filename, void *buf, size_t size)
 	return read_close(fd, buf, size);
 }
 
+
+// Read (potentially big) files in one go. File size is estimated
+// by stat. Extra '\0' byte is appended.
+void* FAST_FUNC xmalloc_read(int fd, size_t *maxsz_p)
+{
+	char *buf;
+	size_t size, rd_size, total;
+	size_t to_read;
+	struct stat st;
+
+	to_read = maxsz_p ? *maxsz_p : (INT_MAX - 4095); /* max to read */
+
+	/* Estimate file size */
+	st.st_size = 0; /* in case fstat fails, assume 0 */
+	fstat(fd, &st);
+	/* /proc/N/stat files report st_size 0 */
+	/* In order to make such files readable, we add small const */
+	size = (st.st_size | 0x3ff) + 1;
+
+	total = 0;
+	buf = NULL;
+	while (1) {
+		if (to_read < size)
+			size = to_read;
+		buf = xrealloc(buf, total + size + 1);
+		rd_size = full_read(fd, buf + total, size);
+		if ((ssize_t)rd_size == (ssize_t)(-1)) { /* error */
+			free(buf);
+			return NULL;
+		}
+		total += rd_size;
+		if (rd_size < size) /* EOF */
+			break;
+		if (to_read <= rd_size)
+			break;
+		to_read -= rd_size;
+		/* grow by 1/8, but in [1k..64k] bounds */
+		size = ((total / 8) | 0x3ff) + 1;
+		if (size > 64*1024)
+			size = 64*1024;
+	}
+	buf = xrealloc(buf, total + 1);
+	buf[total] = '\0';
+
+	if (maxsz_p)
+		*maxsz_p = total;
+	return buf;
+}
+
+#ifdef USING_LSEEK_TO_GET_SIZE
+/* Alternatively, file size can be obtained by lseek to the end.
+ * The code is slightly bigger. Retained in case fstat approach
+ * will not work for some weird cases (/proc, block devices, etc).
+ * (NB: lseek also can fail to work for some weird files) */
+
 // Read (potentially big) files in one go. File size is estimated by
 // lseek to end.
-void *xmalloc_open_read_close(const char *filename, size_t *sizep)
+void* FAST_FUNC xmalloc_open_read_close(const char *filename, size_t *maxsz_p)
 {
 	char *buf;
-	size_t size = sizep ? *sizep : INT_MAX;
+	size_t size;
 	int fd;
 	off_t len;
 
-	fd = xopen(filename, O_RDONLY);
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+
 	/* /proc/N/stat files report len 0 here */
 	/* In order to make such files readable, we add small const */
-	len = xlseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */
-	xlseek(fd, 0, SEEK_SET);
-	if (len < size)
-		size = len;
+	size = 0x3ff; /* read only 1k on unseekable files */
+	len = lseek(fd, 0, SEEK_END) | 0x3ff; /* + up to 1k */
+	if (len != (off_t)-1) {
+		xlseek(fd, 0, SEEK_SET);
+		size = maxsz_p ? *maxsz_p : (INT_MAX - 4095);
+		if (len < size)
+			size = len;
+	}
+
 	buf = xmalloc(size + 1);
 	size = read_close(fd, buf, size);
-	if ((ssize_t)size < 0)
-		bb_perror_msg_and_die("'%s'", filename);
-	xrealloc(buf, size + 1);
+	if ((ssize_t)size < 0) {
+		free(buf);
+		return NULL;
+	}
+	buf = xrealloc(buf, size + 1);
 	buf[size] = '\0';
-	if (sizep)
-		*sizep = size;
+
+	if (maxsz_p)
+		*maxsz_p = size;
+	return buf;
+}
+#endif
+
+// Read (potentially big) files in one go. File size is estimated
+// by stat.
+void* FAST_FUNC xmalloc_open_read_close(const char *filename, size_t *maxsz_p)
+{
+	char *buf;
+	int fd;
+
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+
+	buf = xmalloc_read(fd, maxsz_p);
+	close(fd);
+	return buf;
+}
+
+void* FAST_FUNC xmalloc_xopen_read_close(const char *filename, size_t *maxsz_p)
+{
+	void *buf = xmalloc_open_read_close(filename, maxsz_p);
+	if (!buf)
+		bb_perror_msg_and_die("can't read '%s'", filename);
 	return buf;
 }
+
+int FAST_FUNC open_zipped(const char *fname)
+{
+#if !ZIPPED
+	return open(fname, O_RDONLY);
+#else
+	unsigned char magic[2];
+	char *sfx;
+	int fd;
+#if BB_MMU
+	IF_DESKTOP(long long) int FAST_FUNC (*xformer)(int src_fd, int dst_fd);
+	enum { xformer_prog = 0 };
+#else
+	enum { xformer = 0 };
+	const char *xformer_prog;
+#endif
+
+	fd = open(fname, O_RDONLY);
+	if (fd < 0)
+		return fd;
+
+	sfx = strrchr(fname, '.');
+	if (sfx) {
+		if (ENABLE_FEATURE_SEAMLESS_LZMA && strcmp(sfx, ".lzma") == 0)
+			/* .lzma has no header/signature, just trust it */
+			open_transformer(fd, unpack_lzma_stream, "unlzma");
+		else
+		if ((ENABLE_FEATURE_SEAMLESS_GZ && strcmp(sfx, ".gz") == 0)
+		 || (ENABLE_FEATURE_SEAMLESS_BZ2 && strcmp(sfx, ".bz2") == 0)
+		) {
+			/* .gz and .bz2 both have 2-byte signature, and their
+			 * unpack_XXX_stream wants this header skipped. */
+			xread(fd, &magic, 2);
+#if ENABLE_FEATURE_SEAMLESS_GZ
+#if BB_MMU
+			xformer = unpack_gz_stream;
+#else
+			xformer_prog = "gunzip";
+#endif
+#endif
+			if (!ENABLE_FEATURE_SEAMLESS_GZ
+			 || magic[0] != 0x1f || magic[1] != 0x8b
+			) {
+				if (!ENABLE_FEATURE_SEAMLESS_BZ2
+				 || magic[0] != 'B' || magic[1] != 'Z'
+				) {
+					bb_error_msg_and_die("no gzip"
+						IF_FEATURE_SEAMLESS_BZ2("/bzip2")
+						" magic");
+				}
+#if BB_MMU
+				xformer = unpack_bz2_stream;
+#else
+				xformer_prog = "bunzip2";
+#endif
+			} else {
+#if !BB_MMU
+				/* NOMMU version of open_transformer execs
+				 * an external unzipper that wants
+				 * file position at the start of the file */
+				xlseek(fd, 0, SEEK_SET);
+#endif
+			}
+			open_transformer(fd, xformer, xformer_prog);
+		}
+	}
+
+	return fd;
+#endif
+}
+
+void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_p)
+{
+	int fd;
+	char *image;
+
+	fd = open_zipped(fname);
+	if (fd < 0)
+		return NULL;
+
+	image = xmalloc_read(fd, maxsz_p);
+	if (!image)
+		bb_perror_msg("read error from '%s'", fname);
+	close(fd);
+
+	return image;
+}