Magisk/native/jni/resetprop/persist_properties.c

#include <stdbool.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>

#include <pb.h>
#include <pb_decode.h>
#include <pb_encode.h>

#include "_resetprop.h"
#include "utils.h"
#include "vector.h"

#define PERSISTENT_PROPERTY_DIR  "/data/property"

/* ***********************************************************************
 * Auto generated header and constant definitions compiled from
 * android/platform/system/core/master/init/persistent_properties.proto
 * using Nanopb's protoc
 * Nanopb: https://github.com/nanopb/nanopb
 * ***********************************************************************/

/* Automatically generated nanopb header */
/* Generated by nanopb-0.3.9.1 at Sun Apr 22 14:36:22 2018. */

/* @@protoc_insertion_point(includes) */
#if PB_PROTO_HEADER_VERSION != 30
#error Regenerate this file with the current version of nanopb generator.
#endif

/* Struct definitions */
typedef struct _PersistentProperties {
    pb_callback_t properties;
/* @@protoc_insertion_point(struct:PersistentProperties) */
} PersistentProperties;

typedef struct _PersistentProperties_PersistentPropertyRecord {
    pb_callback_t name;
    bool has_value;
    char value[92];
/* @@protoc_insertion_point(struct:PersistentProperties_PersistentPropertyRecord) */
} PersistentProperties_PersistentPropertyRecord;

/* Default values for struct fields */

/* Initializer values for message structs */
#define PersistentProperties_init_default        {{{NULL}, NULL}}
#define PersistentProperties_PersistentPropertyRecord_init_default {{{NULL}, NULL}, false, ""}
#define PersistentProperties_init_zero           {{{NULL}, NULL}}
#define PersistentProperties_PersistentPropertyRecord_init_zero {{{NULL}, NULL}, false, ""}

/* Field tags (for use in manual encoding/decoding) */
#define PersistentProperties_properties_tag      1
#define PersistentProperties_PersistentPropertyRecord_name_tag 1
#define PersistentProperties_PersistentPropertyRecord_value_tag 2

/* Automatically generated nanopb constant definitions */
/* Generated by nanopb-0.3.9.1 at Sun Apr 22 14:36:22 2018. */

/* Struct field encoding specification for nanopb */
const pb_field_t PersistentProperties_PersistentPropertyRecord_fields[3] = {
		PB_FIELD(  1, STRING  , OPTIONAL, CALLBACK, FIRST, PersistentProperties_PersistentPropertyRecord, name, name, 0),
		PB_FIELD(  2, STRING  , OPTIONAL, STATIC  , OTHER, PersistentProperties_PersistentPropertyRecord, value, name, 0),
		PB_LAST_FIELD
};

const pb_field_t PersistentProperties_fields[2] = {
		PB_FIELD(  1, MESSAGE , REPEATED, CALLBACK, FIRST, PersistentProperties, properties, properties, &PersistentProperties_PersistentPropertyRecord_fields),
		PB_LAST_FIELD
};

/* Maximum encoded size of messages (where known) */
/* PersistentProperties_size depends on runtime parameters */
/* PersistentProperties_PersistentPropertyRecord_size depends on runtime parameters */

/* Message IDs (where set with "msgid" option) */
#ifdef PB_MSGID

#define PROPS_MESSAGES \

#endif
/* @@protoc_insertion_point(eof) */


/* ***************************
 * End of auto generated code
 * ***************************/

static bool name_decode(pb_istream_t *stream, const pb_field_t *field, void **arg) {
	uint8_t *name = xmalloc(stream->bytes_left + 1);
	name[stream->bytes_left] = '\0';
	if (!pb_read(stream, name, stream->bytes_left))
		return false;
	*arg = name;
	return true;
}

static bool name_encode(pb_ostream_t *stream, const pb_field_t *field, void * const *arg) {
	return pb_encode_tag_for_field(stream, field) && pb_encode_string(stream, *arg, strlen(*arg));
}

static bool prop_decode(pb_istream_t *stream, const pb_field_t *field, void **arg) {
	PersistentProperties_PersistentPropertyRecord prop = {};
	prop.name.funcs.decode = name_decode;
	if (!pb_decode(stream, PersistentProperties_PersistentPropertyRecord_fields, &prop))
		return false;
	struct read_cb_t *read_cb = *arg;
	read_cb->func(prop.name.arg, prop.value, read_cb->cookie);
	return true;
}

static bool prop_encode(pb_ostream_t *stream, const pb_field_t *field, void * const *arg) {
	PersistentProperties_PersistentPropertyRecord prop = {};
	prop.name.funcs.encode = name_encode;
	prop.has_value = true;
	struct vector *v = *arg;
	struct prop_t *e;
	vec_for_each(v, e) {
		if (e == NULL)
			continue;
		if (!pb_encode_tag_for_field(stream, field))
			return false;
		prop.name.arg = e->name;
		strcpy(prop.value, e->value);
		if (!pb_encode_submessage(stream, PersistentProperties_PersistentPropertyRecord_fields, &prop))
			return false;
		free(e->name);
		free(e);
	}
	return true;
}

static bool write_callback(pb_ostream_t *stream, const uint8_t *buf, size_t count) {
	int fd = (intptr_t)stream->state;
	return xwrite(fd, buf, count) == count;
}

static pb_ostream_t create_ostream(const char *filename) {
	int fd = creat(filename, 0644);
	pb_ostream_t o = {&write_callback, (void*)(intptr_t)fd, SIZE_MAX, 0};
	return o;
}

static void pb_getprop_cb(const char *name, const char *value, void *v) {
	struct prop_t *prop = v;
	if (prop->name && strcmp(name, prop->name) == 0) {
		strcpy(prop->value, value);
		prop->name = NULL;
	}
}

void persist_getprop_all(struct read_cb_t *read_cb) {
	if (access(PERSISTENT_PROPERTY_DIR "/persistent_properties", R_OK) == 0) {
		LOGD("resetprop: decode with protobuf from [" PERSISTENT_PROPERTY_DIR "/persistent_properties]\n");
		PersistentProperties props = PersistentProperties_init_zero;
		props.properties.funcs.decode = prop_decode;
		props.properties.arg = read_cb;
		uint8_t *buf;
		size_t size;
		mmap_ro(PERSISTENT_PROPERTY_DIR "/persistent_properties", (void **) &buf, &size);
		pb_istream_t stream = pb_istream_from_buffer(buf, size);
		pb_decode(&stream, PersistentProperties_fields, &props);
		munmap(buf, size);
	} else {
		DIR *dir = opendir(PERSISTENT_PROPERTY_DIR);
		struct dirent *entry;
		while ((entry = readdir(dir))) {
			if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0 )
				continue;
			char *value = persist_getprop(entry->d_name);
			if (value) {
				read_cb->func(strdup(entry->d_name), value, read_cb->cookie);
				free(value);
			}
		}
	}
}

char *persist_getprop(const char *name) {
	struct prop_t prop;
	prop.name = (char *) name;
	if (access(PERSISTENT_PROPERTY_DIR "/persistent_properties", R_OK) == 0) {
		struct read_cb_t read_cb = {
			.func = pb_getprop_cb,
			.cookie = &prop
		};
		persist_getprop_all(&read_cb);
		if (prop.name)
			return NULL;
	} else {
		// Try to read from file
		char path[PATH_MAX];
		snprintf(path, sizeof(path), PERSISTENT_PROPERTY_DIR "/%s", name);
		int fd = open(path, O_RDONLY | O_CLOEXEC);
		if (fd < 0)
			return NULL;
		LOGD("resetprop: read prop from [%s]\n", path);
		prop.value[read(fd, prop.value, sizeof(PROP_VALUE_MAX))] = '\0';  // Null terminate the read value
		close(fd);
	}
	return strdup(prop.value);
}

bool persist_deleteprop(const char *name) {
	if (access(PERSISTENT_PROPERTY_DIR "/persistent_properties", R_OK) == 0) {
		struct vector v;
		vec_init(&v);
		struct read_cb_t read_cb = {
			.func = collect_props,
			.cookie = &v
		};
		persist_getprop_all(&read_cb);
		struct prop_t *p;
		bool reencode = false;
		vec_for_each(&v, p) {
			if (strcmp(p->name, name) == 0) {
				// Remove the prop from the list
				free(p->name);
				free(p);
				vec_cur(&v) = NULL;
				reencode = true;
				break;
			}
		}

		if (reencode) {
			// Dump the props back
			PersistentProperties props = PersistentProperties_init_zero;
			pb_ostream_t ostream = create_ostream(PERSISTENT_PROPERTY_DIR "/persistent_properties.tmp");
			props.properties.funcs.encode = prop_encode;
			props.properties.arg = &v;
			LOGD("resetprop: encode with protobuf to [" PERSISTENT_PROPERTY_DIR "/persistent_properties.tmp]\n");
			if (!pb_encode(&ostream, PersistentProperties_fields, &props))
				return false;
			clone_attr(PERSISTENT_PROPERTY_DIR "/persistent_properties", PERSISTENT_PROPERTY_DIR "/persistent_properties.tmp");
			rename(PERSISTENT_PROPERTY_DIR "/persistent_properties.tmp", PERSISTENT_PROPERTY_DIR "/persistent_properties");
		}

		vec_destroy(&v);
		return reencode;
	} else {
		char path[PATH_MAX];
		snprintf(path, sizeof(path), PERSISTENT_PROPERTY_DIR "/%s", name);
		if (unlink(path) == 0) {
			LOGD("resetprop: unlink [%s]\n", path);
			return true;
		}
	}
	return false;
}