20060303

1 files changed, 215 insertions, 0 deletions

diff --git a/utils/libmach/access.c b/utils/libmach/access.c
new file mode 100644
index 00000000..6a58cdea
--- /dev/null
+++ b/utils/libmach/access.c
@@ -0,0 +1,215 @@
+/*
+ * functions to read and write an executable or file image
+ */
+
+#include <lib9.h>
+#include <bio.h>
+#include "mach.h"
+
+static	int	mget(Map*, ulong, char*, int);
+static	int	mput(Map*, ulong, char*, int);
+struct segment*	reloc(Map*, ulong, long*);
+
+/*
+ * routines to get/put various types
+ */
+
+int
+get8(Map *map, ulong addr, vlong *x)
+{
+	if (!map) {
+		werrstr("get8: invalid map");
+		return -1;
+	}
+
+	if (map->nsegs == 1 && map->seg[0].fd < 0) {
+		*x = (vlong)addr;
+		return 1;
+	}
+	if (mget(map, addr, (char *)x, 8) < 0)
+		return -1;
+	*x = machdata->swav(*x);
+	return (1);
+}
+
+int
+get4(Map *map, ulong addr, long *x)
+{
+	if (!map) {
+		werrstr("get4: invalid map");
+		return -1;
+	}
+
+	if (map->nsegs == 1 && map->seg[0].fd < 0) {
+		*x = addr;
+		return 1;
+	}
+	if (mget(map, addr, (char *)x, 4) < 0)
+		return -1;
+	*x = machdata->swal(*x);
+	return (1);
+}
+
+int
+get2(Map *map, ulong addr, ushort *x)
+{
+	if (!map) {
+		werrstr("get2: invalid map");
+		return -1;
+	}
+
+	if (map->nsegs == 1 && map->seg[0].fd < 0) {
+		*x = addr;
+		return 1;
+	}
+	if (mget(map, addr, (char *)x, 2) < 0)
+		return -1;
+	*x = machdata->swab(*x);
+	return (1);
+}
+
+int
+get1(Map *map, ulong addr, uchar *x, int size)
+{
+	uchar *cp;
+
+	if (!map) {
+		werrstr("get1: invalid map");
+		return -1;
+	}
+
+	if (map->nsegs == 1 && map->seg[0].fd < 0) {
+		cp = (uchar*)&addr;
+		while (cp < (uchar*)(&addr+1) && size-- > 0)
+			*x++ = *cp++;
+		while (size-- > 0)
+			*x++ = 0;
+	} else
+		return mget(map, addr, (char*)x, size);
+	return 1;
+}
+
+int
+put8(Map *map, ulong addr, vlong v)
+{
+	if (!map) {
+		werrstr("put8: invalid map");
+		return -1;
+	}
+	v = machdata->swav(v);
+	return mput(map, addr, (char *)&v, 8);
+}
+
+int
+put4(Map *map, ulong addr, long v)
+{
+	if (!map) {
+		werrstr("put4: invalid map");
+		return -1;
+	}
+	v = machdata->swal(v);
+	return mput(map, addr, (char *)&v, 4);
+}
+
+int
+put2(Map *map, ulong addr, ushort v)
+{
+	if (!map) {
+		werrstr("put2: invalid map");
+		return -1;
+	}
+	v = machdata->swab(v);
+	return mput(map, addr, (char *)&v, 2);
+}
+
+int
+put1(Map *map, ulong addr, uchar *v, int size)
+{
+	if (!map) {
+		werrstr("put1: invalid map");
+		return -1;
+	}
+	return mput(map, addr, (char *)v, size);
+}
+
+static int
+mget(Map *map, ulong addr, char *buf, int size)
+{
+	long off;
+	int i, j, k;
+	struct segment *s;
+
+	s = reloc(map, addr, &off);
+	if (!s)
+		return -1;
+	if (s->fd < 0) {
+		werrstr("unreadable map");
+		return -1;
+	}
+	if (s->mget)
+		return s->mget(s, addr, off, buf, size);
+	seek(s->fd, off, 0);
+	for (i = j = 0; i < 2; i++) {	/* in case read crosses page */
+		k = read(s->fd, buf, size-j);
+		if (k < 0) {
+			werrstr("can't read address %lux: %r", addr);
+			return -1;
+		}
+		j += k;
+		if (j == size)
+			return j;
+	}
+	werrstr("partial read at address %lux", addr);
+	return -1;
+}
+
+static int
+mput(Map *map, ulong addr, char *buf, int size)
+{
+	long off;
+	int i, j, k;
+	struct segment *s;
+
+	s = reloc(map, addr, &off);
+	if (!s)
+		return -1;
+	if (s->fd < 0) {
+		werrstr("unwritable map");
+		return -1;
+	}
+	if (s->mput)
+		return s->mput(s, addr, off, buf, size);
+
+	seek(s->fd, off, 0);
+	for (i = j = 0; i < 2; i++) {	/* in case read crosses page */
+		k = write(s->fd, buf, size-j);
+		if (k < 0) {
+			werrstr("can't write address %lux: %r", addr);
+			return -1;
+		}
+		j += k;
+		if (j == size)
+			return j;
+	}
+	werrstr("partial write at address %lux", addr);
+	return -1;
+}
+
+/*
+ *	convert address to file offset; returns nonzero if ok
+ */
+struct segment*
+reloc(Map *map, ulong addr, long *offp)
+{
+	int i;
+
+	for (i = 0; i < map->nsegs; i++) {
+		if (map->seg[i].inuse)
+		if (map->seg[i].b <= addr && addr < map->seg[i].e) {
+			*offp = addr + map->seg[i].f - map->seg[i].b;
+			return &map->seg[i];
+		}
+	}
+	werrstr("can't translate address %lux", addr);
+	return 0;
+}