libposix: implemented libposix_getdents

sys/include/posix.h

@@ -36,6 +36,7 @@
 
 #ifndef _LIBPOSIX_DIRENT
 #define _LIBPOSIX_DIRENT
+
 /* dirent alias of stat(5) message.
  * We (ab)use the fact that both 9P and Jehanne are little endian.
  * With the new file protocol this might change.
@@ -53,7 +54,7 @@ struct __attribute__((__packed__)) dirent
 	unsigned int	__pad4__;	/* don't use */
 	unsigned long	d_filesize;
 	unsigned short	d_namlen;
-	char*		d_name;
+	char		d_name[];
 };
 
 #define _DIRENT_HAVE_D_RECLEN
@@ -64,6 +65,16 @@ struct __attribute__((__packed__)) dirent
 #define _DIRENT_HAVE_D_NAMLEN
 #undef _DIRENT_HAVE_D_OFF
 
+#define	DT_UNKNOWN	 0
+#define	DT_FIFO		 1
+#define	DT_CHR		 2
+#define	DT_DIR		 4
+#define	DT_BLK		 6
+#define	DT_REG		 8
+#define	DT_LNK		10
+#define	DT_SOCK		12
+#define	DT_WHT		14
+
 #endif /* _LIBPOSIX_DIRENT */
 
 #ifndef _LIBPOSIX_H
@@ -110,7 +121,7 @@ extern void POSIX_free(void *ptr);
 extern unsigned int POSIX_sleep(unsigned int seconds);
 extern int POSIX_pipe(int *errnop, int fildes[2]);
 
-extern int libposix_getdents(int *errnop, int fd, struct dirent *buf, int buf_bytes);
+extern int libposix_getdents(int *errnop, int fd, char *buf, int buf_bytes);
 
 /* Library initialization
  */

sys/src/lib/posix/files.c

@@ -17,6 +17,7 @@
  */
 #include <u.h>
 #include <lib9.h>
+#include <9P2000.h>
 #include <posix.h>
 #include "internal.h"
 
@@ -360,7 +361,84 @@ POSIX_stat(int *errnop, const char *file, void *pstat)
 }
 
 int
-libposix_getdents(int *errnop, int fd, struct dirent *buf, int buf_bytes)
+libposix_getdents(int *errnop, int fd, char *buf, int buf_bytes)
 {
-	return 0;
+#define MINSTATLEN	(STATFIXLEN + 4) /* 4 = min (1 char) name, uid, gid, muid */
+
+	int r;
+	Dir *d;
+	struct dirent *dp;
+	char *p;
+
+	if(fd < 0)
+		goto FailWithEBADF;
+	if(buf == nil)
+		goto FailWithEFAULT;
+	if(buf_bytes < MINSTATLEN)
+		goto FailWithEINVAL;
+
+	d = dirfstat(fd);
+	if(d == nil)
+		goto FailWithENOENT;	/* removed? */
+	r = d->mode & DMDIR;
+	free(d);
+
+	if(r == 0)
+		goto FailWithENOTDIR;	/* not a directory */
+
+	r = read(fd, buf, buf_bytes);
+	if(r < 0)
+		goto FailWithENOENT;	/* removed? */
+	if(r < MINSTATLEN)
+		goto FailWithEIO;
+
+	p = buf;
+	while(p - buf < r){
+		/* here we adjust 9P2000 stat info to match
+		 * dirent specification
+		 */
+		dp = (struct dirent *)p;
+
+		/* the count field in stat structure exclude itself */
+		dp->d_reclen += BIT16SZ;
+
+		/* 9P2000 strings are not NUL-terminated */
+		dp->d_name[dp->d_namlen] = '\0';
+
+		/* we have to map types to UNIX */
+		if(dp->d_type & (DMDIR >> 24))
+			dp->d_type = DT_DIR;
+		else if(dp->__pad1__ == '|')	/* kernel device == devpipe */
+			dp->d_type = DT_FIFO;
+		else
+			dp->d_type = DT_REG;	/* UNIX lack fantasy :-) */
+
+		p += dp->d_reclen;
+	}
+
+	return r;
+
+FailWithEBADF:
+	*errnop = __libposix_get_errno(PosixEBADF);
+	return -1;
+
+FailWithEFAULT:
+	*errnop = __libposix_get_errno(PosixEFAULT);
+	return -1;
+
+FailWithEINVAL:
+	*errnop = __libposix_get_errno(PosixEINVAL);
+	return -1;
+
+FailWithENOENT:
+	*errnop = __libposix_get_errno(PosixENOENT);
+	return -1;
+
+FailWithENOTDIR:
+	*errnop = __libposix_get_errno(PosixENOTDIR);
+	return -1;
+
+FailWithEIO:
+	*errnop = __libposix_get_errno(PosixEIO);
+	return -1;
 }