tools: acrn-crashlog: New apis to replace losetup and fdisk

This patch adds new apis to replace commands losetup and fdisk.
Main changes include:
1. impletement apis to operate loop devices directly.
2. impletement apis to get partition information from image file.

Signed-off-by: Liu, Xinwu <xinwu.liu@intel.com>
Acked-by: Chen Gang <gang.c.chen@intel.com>

Author: lauxinw

tools/acrn-crashlog/acrnprobe/Makefile

@@ -3,7 +3,7 @@ MINOR_VERSION=0
 
 VERSION_H	= $(BUILDDIR)/include/acrnprobe/version.h
 
-LIBS		= -lpthread -lxml2 -lcrypto -lrt $(EXTRA_LIBS)
+LIBS		= -lpthread -lxml2 -lcrypto -lrt -lblkid $(EXTRA_LIBS)
 INCLUDE		+= -I $(CURDIR)/include -I /usr/include/libxml2
 INCLUDE		+= -I $(BUILDDIR)/include/acrnprobe
 CFLAGS 		+= $(INCLUDE)
@@ -36,7 +36,8 @@ $(BUILDDIR)/acrnprobe/bin/acrnprobe: $(BUILDDIR)/acrnprobe/obj/main.o \
 	$(BUILDDIR)/acrnprobe/obj/property.o \
 	$(BUILDDIR)/acrnprobe/obj/probeutils.o \
 	$(BUILDDIR)/acrnprobe/obj/history.o \
-	$(BUILDDIR)/acrnprobe/obj/android_events.o
+	$(BUILDDIR)/acrnprobe/obj/android_events.o \
+	$(BUILDDIR)/acrnprobe/obj/loop.o
 	$(CC) -o $@ $^ $(LDFLAGS)
 
 .PHONY: clean

tools/acrn-crashlog/acrnprobe/loop.c

@@ -0,0 +1,232 @@
+/*
+ * Copyright (C) 2018 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <linux/loop.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <blkid/blkid.h>
+#include <ext2fs/ext2fs.h>
+#include "log_sys.h"
+
+#define DEV_LOOP_CTL "/dev/loop-control"
+
+static int get_par_startaddr_from_img(const char *img,
+					const char *target_parname,
+					unsigned long long *start)
+{
+	blkid_probe pr;
+	blkid_partlist ls;
+	blkid_partition par;
+	int i;
+	int nparts;
+	const char *par_name;
+	unsigned int sector_size;
+	unsigned long long par_start;
+
+	if (!img || !target_parname || !start)
+		return -1;
+
+	pr = blkid_new_probe_from_filename(img);
+	if (!pr) {
+		LOGE("blkid new probe failed\n");
+		return -1;
+	}
+	ls = blkid_probe_get_partitions(pr);
+	if (!ls) {
+		LOGE("blkid get partitions failed\n");
+		goto err;
+	}
+	nparts = blkid_partlist_numof_partitions(ls);
+	if (nparts <= 0) {
+		LOGE("(%d) partitions in (%s)??\n", nparts, img);
+		goto err;
+	}
+
+	for (i = 0; i < nparts; i++) {
+		par = blkid_partlist_get_partition(ls, i);
+		par_name = blkid_partition_get_name(par);
+		if (!par_name) {
+			LOGW("A partition in (%s) don't have name??\n", img);
+			continue;
+		}
+		if (!strcmp(par_name, target_parname))
+			goto found;
+	}
+	LOGE("no partition of (%s) is named %s\n", img, target_parname);
+err:
+	blkid_free_probe(pr);
+	return -1;
+found:
+	sector_size = blkid_probe_get_sectorsize(pr);
+	par_start = (unsigned long long)blkid_partition_get_start(par);
+	*start = par_start * sector_size;
+	blkid_free_probe(pr);
+	return 0;
+}
+
+int loopdev_num_get_free(void)
+{
+	int loopctlfd;
+	int devnr;
+
+	loopctlfd = open(DEV_LOOP_CTL, O_RDONLY);
+	if (loopctlfd == -1) {
+		LOGE("failed to open %s, error (%s)\n", DEV_LOOP_CTL,
+		     strerror(errno));
+		return -errno;
+	}
+
+	devnr = ioctl(loopctlfd, LOOP_CTL_GET_FREE);
+	if (devnr == -1) {
+		LOGE("failed to get free loopdev, error (%s)\n",
+		     strerror(errno));
+		close(loopctlfd);
+		return -errno;
+	}
+
+	close(loopctlfd);
+	return devnr;
+}
+
+static int loopdev_set_status(const char *loopdev,
+				const struct loop_info64 *info)
+{
+	int loopfd;
+	int res;
+
+	if (!loopdev || !info)
+		return -EINVAL;
+
+	loopfd = open(loopdev, O_RDWR);
+	if (loopfd == -1) {
+		LOGE("failed to open (%s), error(%s)\n", loopdev,
+		     strerror(errno));
+		return -errno;
+	}
+
+	res = ioctl(loopfd, LOOP_SET_STATUS64, info);
+	if (res == -1) {
+		LOGE("failed to set info to (%s), error(%s)\n", loopdev,
+		     strerror(errno));
+		close(loopfd);
+		return -errno;
+	}
+
+	close(loopfd);
+	return 0;
+}
+
+static int loopdev_set_img(const char *loopdev, const char *img_path)
+{
+	int loopfd;
+	int imgfd;
+	int res;
+
+	if (!loopdev || !img_path)
+		return -EINVAL;
+
+	loopfd = open(loopdev, O_WRONLY);
+	if (loopfd == -1) {
+		LOGE("failed to open %s, error (%s)\n", loopdev,
+		     strerror(errno));
+		return -errno;
+	}
+
+	imgfd = open(img_path, O_RDONLY);
+	if (imgfd == -1) {
+		LOGE("failed to open %s, error (%s)\n", img_path,
+		     strerror(errno));
+		close(loopfd);
+		return -errno;
+	}
+
+	res = ioctl(loopfd, LOOP_SET_FD, imgfd);
+	if (res == -1) {
+		LOGE("failed to set (%s) to (%s), error (%s)\n", img_path,
+		     loopdev, strerror(errno));
+		close(loopfd);
+		close(imgfd);
+		return -errno;
+	}
+
+	close(loopfd);
+	close(imgfd);
+	return 0;
+}
+
+int loopdev_set_img_par(const char *loopdev, const char *img_path,
+			const char *parname)
+{
+	struct loop_info64 info;
+	unsigned long long par_start;
+	int res;
+
+	if (!loopdev || !img_path || !parname)
+		return -1;
+
+	res = get_par_startaddr_from_img(img_path, parname, &par_start);
+	if (res == -1) {
+		LOGE("failed to get data par startaddr\n");
+		return -1;
+	}
+
+	res = loopdev_set_img(loopdev, img_path);
+	if (res) {
+		LOGE("failed to set img (%s) to (%s), error (%s)\n",
+		       img_path, loopdev, strerror(-res));
+		return -1;
+	}
+
+	memset(&info, 0, sizeof(info));
+	info.lo_offset = par_start;
+
+	res = loopdev_set_status(loopdev, &info);
+	if (res < 0) {
+		LOGE("failed to set loopdev, error (%s)\n", strerror(-res));
+		return -1;
+	}
+	return 0;
+}
+
+int loopdev_check_parname(const char *loopdev, const char *parname)
+{
+	struct ext2_super_block super;
+	int fd;
+	const int skiprate = 512;
+	loff_t sk = 0;
+
+	if (!loopdev || !parname)
+		return -ENOENT;
+
+	/* quickly find super block */
+	fd = open(loopdev, O_RDONLY);
+	if (fd == -1) {
+		LOGE("failed to open (%s), error(%s)\n", loopdev,
+		     strerror(errno));
+		return -errno;
+	}
+	for (; lseek64(fd, sk, SEEK_SET) != -1 &&
+	       read(fd, &super, 512) == 512; sk += skiprate) {
+		if (super.s_magic != EXT2_SUPER_MAGIC)
+			continue;
+
+		LOGD("find super block at +%ld\n", sk);
+		/* only look into the primary super block */
+		if (super.s_volume_name[0]) {
+			close(fd);
+			return !strcmp(super.s_volume_name, parname);
+		}
+		break;
+	}
+
+	close(fd);
+	return 0;
+}