criu/protobuf.c

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <ctype.h>

#include <google/protobuf-c/protobuf-c.h>

#include "crtools.h"
#include "compiler.h"
#include "types.h"
#include "log.h"
#include "util.h"
#include "string.h"
#include "sockets.h"

#include "protobuf.h"
#include "protobuf/inventory.pb-c.h"
#include "protobuf/regfile.pb-c.h"
#include "protobuf/eventfd.pb-c.h"
#include "protobuf/eventpoll.pb-c.h"
#include "protobuf/signalfd.pb-c.h"
#include "protobuf/inotify.pb-c.h"
#include "protobuf/core.pb-c.h"
#include "protobuf/mm.pb-c.h"
#include "protobuf/pipe.pb-c.h"
#include "protobuf/fifo.pb-c.h"
#include "protobuf/fdinfo.pb-c.h"
#include "protobuf/pipe-data.pb-c.h"
#include "protobuf/pstree.pb-c.h"
#include "protobuf/sa.pb-c.h"
#include "protobuf/sk-unix.pb-c.h"
#include "protobuf/sk-inet.pb-c.h"
#include "protobuf/packet-sock.pb-c.h"
#include "protobuf/sk-packet.pb-c.h"
#include "protobuf/creds.pb-c.h"
#include "protobuf/itimer.pb-c.h"
#include "protobuf/utsns.pb-c.h"
#include "protobuf/ipc-var.pb-c.h"
#include "protobuf/ipc-shm.pb-c.h"
#include "protobuf/ipc-msg.pb-c.h"
#include "protobuf/ipc-sem.pb-c.h"
#include "protobuf/fs.pb-c.h"
#include "protobuf/remap-file-path.pb-c.h"
#include "protobuf/ghost-file.pb-c.h"
#include "protobuf/mnt.pb-c.h"
#include "protobuf/netdev.pb-c.h"
#include "protobuf/tcp-stream.pb-c.h"
#include "protobuf/tty.pb-c.h"

typedef size_t (*pb_getpksize_t)(void *obj);
typedef size_t (*pb_pack_t)(void *obj, void *where);
typedef void  *(*pb_unpack_t)(void *allocator, size_t size, void *from);
typedef void   (*pb_free_t)(void *obj, void *allocator);

struct cr_pb_message_desc {
	pb_getpksize_t	getpksize;
	pb_pack_t	pack;
	pb_unpack_t	unpack;
	pb_free_t	free;
	const ProtobufCMessageDescriptor *pb_desc;
};

#define PB_PACK_TYPECHECK(__o, __fn)	({ if (0) __fn##__pack(__o, NULL); (pb_pack_t)&__fn##__pack; })
#define PB_GPS_TYPECHECK(__o, __fn)	({ if (0) __fn##__get_packed_size(__o); (pb_getpksize_t)&__fn##__get_packed_size; })
#define PB_UNPACK_TYPECHECK(__op, __fn)	({ if (0) *__op = __fn##__unpack(NULL, 0, NULL); (pb_unpack_t)&__fn##__unpack; })
#define PB_FREE_TYPECHECK(__o, __fn)	({ if (0) __fn##__free_unpacked(__o, NULL); (pb_free_t)&__fn##__free_unpacked; })

/*
 * This should be explicitly "called" to do type-checking
 */

#define CR_PB_MDESC_INIT(__var, __type, __name)	do {				\
		__var.getpksize = PB_GPS_TYPECHECK((__type *)NULL, __name);	\
		__var.pack = PB_PACK_TYPECHECK((__type *)NULL, __name);		\
		__var.unpack = PB_UNPACK_TYPECHECK((__type **)NULL, __name);	\
		__var.free = PB_FREE_TYPECHECK((__type *)NULL, __name);		\
		__var.pb_desc = &__name##__descriptor;				\
	} while (0)

static struct cr_pb_message_desc cr_pb_descs[PB_MAX];

#define CR_PB_DESC(__type, __vtype, __ftype)	\
	CR_PB_MDESC_INIT(cr_pb_descs[PB_##__type], __vtype##Entry, __ftype##_entry)

void cr_pb_init(void)
{
	CR_PB_DESC(INVENTORY,		Inventory,	inventory);
	CR_PB_DESC(FDINFO,		Fdinfo,		fdinfo);
	CR_PB_DESC(REG_FILES,		RegFile,	reg_file);
	CR_PB_DESC(EVENTFD,		EventfdFile,	eventfd_file);
	CR_PB_DESC(EVENTPOLL,		EventpollFile,	eventpoll_file);
	CR_PB_DESC(EVENTPOLL_TFD,	EventpollTfd,	eventpoll_tfd);
	CR_PB_DESC(SIGNALFD,		Signalfd,	signalfd);
	CR_PB_DESC(INOTIFY,		InotifyFile,	inotify_file);
	CR_PB_DESC(INOTIFY_WD,		InotifyWd,	inotify_wd);
	CR_PB_DESC(CORE,		Core,		core);
	CR_PB_DESC(MM,			Mm,		mm);
	CR_PB_DESC(VMAS,		Vma,		vma);
	CR_PB_DESC(PIPES,		Pipe,		pipe);
	CR_PB_DESC(PIPES_DATA,		PipeData,	pipe_data);
	CR_PB_DESC(FIFO,		Fifo,		fifo);
	CR_PB_DESC(PSTREE,		Pstree,		pstree);
	CR_PB_DESC(SIGACT,		Sa,		sa);
	CR_PB_DESC(UNIXSK,		UnixSk,		unix_sk);
	CR_PB_DESC(INETSK,		InetSk,		inet_sk);
	CR_PB_DESC(SK_QUEUES,		SkPacket,	sk_packet);
	CR_PB_DESC(ITIMERS,		Itimer,		itimer);
	CR_PB_DESC(CREDS,		Creds,		creds);
	CR_PB_DESC(UTSNS,		Utsns,		utsns);
	CR_PB_DESC(IPCNS_VAR,		IpcVar,		ipc_var);
	CR_PB_DESC(IPCNS_SHM,		IpcShm,		ipc_shm);
	/* There's no _entry suffix in this one :( */
	CR_PB_MDESC_INIT(cr_pb_descs[PB_IPCNS_MSG],	IpcMsg, ipc_msg);
	CR_PB_DESC(IPCNS_MSG_ENT,	IpcMsg,		ipc_msg);
	CR_PB_DESC(IPCNS_SEM,		IpcSem,		ipc_sem);
	CR_PB_DESC(FS,			Fs,		fs);
	CR_PB_DESC(REMAP_FPATH,		RemapFilePath,	remap_file_path);
	CR_PB_DESC(GHOST_FILE,		GhostFile,	ghost_file);
	CR_PB_DESC(TCP_STREAM,		TcpStream,	tcp_stream);
	CR_PB_DESC(MOUNTPOINTS,		Mnt,		mnt);
	CR_PB_DESC(NETDEV,		NetDevice,	net_device);
	CR_PB_DESC(PACKETSK,		PacketSock,	packet_sock);
	CR_PB_DESC(TTY,			TtyFile,	tty_file);
	CR_PB_DESC(TTY_INFO,		TtyInfo,	tty_info);
}

/*
 * To speed up reading of packed objects
 * by providing space on stack, this should
 * be more than enough for most objects.
 */
#define PB_PKOBJ_LOCAL_SIZE	1024

#define INET_ADDR_LEN		40

struct pb_pr_field_s {
	void *data;
	int number;
	int depth;
	int count;
	char fmt[32];
};

typedef struct pb_pr_field_s pb_pr_field_t;

struct pb_pr_ctrl_s {
	void *arg;
	int single_entry;
	const char *pretty_fmt;
	pb_pr_field_t cur;
};

typedef struct pb_pr_ctrl_s pb_pr_ctl_t;
typedef int (*pb_pr_show_t)(pb_pr_field_t *field);

static int pb_msg_int32x(pb_pr_field_t *field)
{
	pr_msg("%#x", *(int *)field->data);
	return 0;
}

static int pb_msg_int64x(pb_pr_field_t *field)
{
	pr_msg("%#016lx", *(long *)field->data);
	return 0;
}

static int pb_msg_string(pb_pr_field_t *field)
{
	pr_msg("\"%s\"",	*(char **)field->data);
	return 0;
}

static int pb_msg_unk(pb_pr_field_t *field)
{
	pr_msg("unknown object %p", field->data);
	return 0;
}

static inline void print_tabs(pb_pr_ctl_t *ctl)
{
	int counter = ctl->cur.depth;

	if (!ctl->single_entry)
		return;

	while (counter--)
		pr_msg("\t");
}

static void print_nested_message_braces(pb_pr_ctl_t *ctl, int right_brace)
{
	if (right_brace)
		print_tabs(ctl);
	pr_msg("%s%s", (right_brace) ? "}" : "{", (ctl->single_entry) ? "\n" : " ");
}

static void pb_show_msg(const void *msg, pb_pr_ctl_t *ctl);

static int show_nested_message(pb_pr_field_t *field)
{
	pb_pr_ctl_t *ctl = container_of(field, pb_pr_ctl_t, cur);

	print_nested_message_braces(ctl, 0);
	field->depth++;
	pb_show_msg(field->data, ctl);
	field->depth--;
	print_nested_message_braces(ctl, 1);
	return 0;
}

static int show_enum(pb_pr_field_t *field)
{
	pb_pr_ctl_t *ctl = container_of(field, pb_pr_ctl_t, cur);
	ProtobufCEnumDescriptor *d = ctl->arg;
	const char *val_name = NULL;
	int val, i;

	val = *(int *)field->data;
	for (i = 0; i < d->n_values; i++)
		if (d->values[i].value == val) {
			val_name = d->values[i].name;
			break;
		}

	if (val_name != NULL)
		pr_msg("%s", val_name);
	else
		pr_msg("%d", val);
	return 0;
}

static int show_bool(pb_pr_field_t *field)
{
	protobuf_c_boolean val = *(protobuf_c_boolean *)field->data;

	if (val)
		pr_msg("True");
	else
		pr_msg("False");
	return 0;
}

static int show_bytes(pb_pr_field_t *field)
{
	ProtobufCBinaryData *bytes = (ProtobufCBinaryData *)field->data;
	int i = 0;

	while (i < bytes->len)
		pr_msg("%02x ", bytes->data[i++]);
	return 0;
}

static size_t pb_show_prepare_field_context(const ProtobufCFieldDescriptor *fd,
					  pb_pr_ctl_t *ctl)
{
	pb_pr_field_t *field = &ctl->cur;
	size_t fsize = 0;

	switch (fd->type) {
	case PROTOBUF_C_TYPE_ENUM:
		ctl->arg = (void *)fd->descriptor;
	case PROTOBUF_C_TYPE_INT32:
	case PROTOBUF_C_TYPE_SINT32:
	case PROTOBUF_C_TYPE_UINT32:
	case PROTOBUF_C_TYPE_SFIXED32:
	case PROTOBUF_C_TYPE_FLOAT:
		fsize = 4;
		break;
	case PROTOBUF_C_TYPE_INT64:
	case PROTOBUF_C_TYPE_SINT64:
	case PROTOBUF_C_TYPE_SFIXED64:
	case PROTOBUF_C_TYPE_FIXED32:
	case PROTOBUF_C_TYPE_UINT64:
	case PROTOBUF_C_TYPE_FIXED64:
	case PROTOBUF_C_TYPE_DOUBLE:
		fsize = 8;
		break;
	case PROTOBUF_C_TYPE_MESSAGE:
		ctl->arg = (void *)fd->descriptor;
		field->data = (void *)(*(long *)field->data);
	case PROTOBUF_C_TYPE_STRING:
		fsize = sizeof (void *);
		break;
	case PROTOBUF_C_TYPE_BOOL:
		fsize = sizeof (protobuf_c_boolean);
		break;
	case PROTOBUF_C_TYPE_BYTES:
		fsize = sizeof (ProtobufCBinaryData);
		break;
	default:
		BUG();
	}
	return fsize;
}

static int pb_show_pretty(pb_pr_field_t *field)
{
	switch (field->fmt[0]) {
	case '%':
		pr_msg(field->fmt, *(long *)field->data);
		break;
	case 'S':
		{
			ProtobufCBinaryData *name = (ProtobufCBinaryData *)field->data;
			int i;

			for (i = 0; i < name->len; i++) {
				char c = (char)name->data[i];

				if (isprint(c))
					pr_msg("%c", c);
				else if (c != 0)
					pr_msg(".");
			}
			break;
		}
	case 'A':
		{
			char addr[INET_ADDR_LEN] = "<unknown>";
			int family = (field->count == 1) ? AF_INET : AF_INET6;

			if (inet_ntop(family, (void *)field->data, addr,
				      INET_ADDR_LEN) == NULL)
				pr_msg("failed to translate");
			else
				pr_msg("%s", addr);
		}
		return 1;
	}
	return 0;
}

static int pb_field_show_pretty(pb_pr_ctl_t *ctl)
{
	pb_pr_field_t *field = &ctl->cur;
	int found;
	char cookie[32];
	const char *ptr;

	if (!ctl->pretty_fmt || field->depth)
		return 0;

	sprintf(cookie, " %d:", field->number);
	if (!strncmp(ctl->pretty_fmt, &cookie[1], strlen(&cookie[1])))
		ptr = ctl->pretty_fmt;
	else {
		ptr = strstr(ctl->pretty_fmt, cookie);
		if (!ptr)
			return 0;
	}
	found = sscanf(ptr, "%*[ 1-9:]%s", field->fmt);
	BUG_ON(found > 1);
	return found;
}

static pb_pr_show_t get_pb_show_function(int type)
{
	switch (type) {
	case PROTOBUF_C_TYPE_INT32:
	case PROTOBUF_C_TYPE_SINT32:
	case PROTOBUF_C_TYPE_UINT32:
	case PROTOBUF_C_TYPE_SFIXED32:
		return pb_msg_int32x;
	case PROTOBUF_C_TYPE_INT64:
	case PROTOBUF_C_TYPE_SINT64:
	case PROTOBUF_C_TYPE_SFIXED64:
	case PROTOBUF_C_TYPE_FIXED32:
	case PROTOBUF_C_TYPE_UINT64:
	case PROTOBUF_C_TYPE_FIXED64:
		return pb_msg_int64x;
	case PROTOBUF_C_TYPE_STRING:
		return pb_msg_string;
	case PROTOBUF_C_TYPE_MESSAGE:
		return show_nested_message;
	case PROTOBUF_C_TYPE_ENUM:
		return show_enum;
	case PROTOBUF_C_TYPE_BOOL:
		return show_bool;
	case PROTOBUF_C_TYPE_BYTES:
		return show_bytes;
	case PROTOBUF_C_TYPE_FLOAT:
	case PROTOBUF_C_TYPE_DOUBLE:
		break;
	default:
		BUG();
	}
	return pb_msg_unk;
}

static pb_pr_show_t get_show_function(int type, pb_pr_ctl_t *ctl)
{
	if (pb_field_show_pretty(ctl))
		return pb_show_pretty;
	return get_pb_show_function(type);
}

static void pb_show_repeated(pb_pr_ctl_t *ctl, int nr_fields, pb_pr_show_t show,
			  size_t fsize)
{
	pb_pr_field_t *field = &ctl->cur;
	unsigned long counter;
	int done;

	if (nr_fields == 0) {
		pr_msg("<empty>");
		return;
	}

	field->count = nr_fields;
	done = show(field);
	if (done)
		return;

	field->data += fsize;

	for (counter = 0; counter < nr_fields - 1; counter++, field->data += fsize) {
		pr_msg(":");
		show(field);
	}
}

static void pb_show_field(const ProtobufCFieldDescriptor *fd,
			  int nr_fields, pb_pr_ctl_t *ctl)
{
	pb_pr_show_t show;

	print_tabs(ctl);
	pr_msg("%s: ", fd->name);

	show = get_show_function(fd->type, ctl);

	pb_show_repeated(ctl, nr_fields, show, pb_show_prepare_field_context(fd, ctl));

	if (ctl->single_entry)
		pr_msg("\n");
	else
		pr_msg(" ");
}

static int pb_optional_field_present(const ProtobufCFieldDescriptor *field,
		const void *msg)
{
	if ((field->type == PROTOBUF_C_TYPE_MESSAGE) ||
		(field->type == PROTOBUF_C_TYPE_STRING)) {
		const void *opt_flag = * (const void * const *)(msg + field->offset);

		if ((opt_flag == NULL) || (opt_flag == field->default_value))
			return 0;
	} else {
		const protobuf_c_boolean *has = msg + field->quantifier_offset;

		if (!*has)
			return 0;
	}
	return 1;
}

static void pb_show_msg(const void *msg, pb_pr_ctl_t *ctl)
{
	int i;
	const ProtobufCMessageDescriptor *md = ctl->arg;

	BUG_ON(md == NULL);

	for (i = 0; i < md->n_fields; i++) {
		const ProtobufCFieldDescriptor fd = md->fields[i];
		unsigned long *data;
		size_t nr_fields;

		nr_fields = 1;
		data = (unsigned long *)(msg + fd.offset);

		if (fd.label == PROTOBUF_C_LABEL_OPTIONAL) {
			if (!pb_optional_field_present(&fd, msg))
				continue;
		}

		if (fd.label == PROTOBUF_C_LABEL_REPEATED) {
			nr_fields = *(size_t *)(msg + fd.quantifier_offset);
			data = (unsigned long *)*data;
		}

		ctl->cur.data = data;
		ctl->cur.number = i + 1;

		pb_show_field(&fd, nr_fields, ctl);
	}
}

static inline void pb_no_payload(int fd, void *obj, int flags) { }

void do_pb_show_plain(int fd, int type, int single_entry,
		void (*payload_hadler)(int fd, void *obj, int flags),
		int flags, const char *pretty_fmt)
{
	pb_pr_ctl_t ctl = {NULL, single_entry, pretty_fmt};
	void (*handle_payload)(int fd, void *obj, int flags);

	if (!cr_pb_descs[type].pb_desc) {
		pr_err("Wrong object requested %d\n", type);
		return;
	}

	handle_payload = (payload_hadler) ? : pb_no_payload;

	while (1) {
		void *obj;

		if (pb_read_one_eof(fd, &obj, type) <= 0)
			break;

		ctl.arg = (void *)cr_pb_descs[type].pb_desc;
		pb_show_msg(obj, &ctl);
		handle_payload(fd, obj, flags);
		cr_pb_descs[type].free(obj, NULL);
		if (single_entry)
			break;
		pr_msg("\n");
	}
}

/*
 * Reads PB record (header + packed object) from file @fd and unpack
 * it with @unpack procedure to the pointer @pobj
 *
 *  1 on success
 * -1 on error (or EOF met and @eof set to false)
 *  0 on EOF and @eof set to true
 *
 * Don't forget to free memory granted to unpacked object in calling code if needed
 */

int do_pb_read_one(int fd, void **pobj, int type, bool eof)
{
	u8 local[PB_PKOBJ_LOCAL_SIZE];
	void *buf = (void *)&local;
	u32 size;
	int ret;

	if (!cr_pb_descs[type].pb_desc) {
		pr_err("Wrong object requested %d\n", type);
		return -1;
	}

	*pobj = NULL;

	ret = read(fd, &size, sizeof(size));
	if (ret == 0) {
		if (eof) {
			return 0;
		} else {
			pr_err("Unexpected EOF\n");
			return -1;
		}
	} else if (ret < sizeof(size)) {
		pr_perror("Read %d bytes while %d expected",
			  ret, (int)sizeof(size));
		return -1;
	}

	if (size > sizeof(local)) {
		ret = -1;
		buf = xmalloc(size);
		if (!buf)
			goto err;
	}

	ret = read(fd, buf, size);
	if (ret < 0) {
		pr_perror("Can't read %d bytes from file", size);
		goto err;
	} else if (ret != size) {
		pr_perror("Read %d bytes while %d expected", ret, size);
		ret = -1;
		goto err;
	}

	*pobj = cr_pb_descs[type].unpack(NULL, size, buf);
	if (!*pobj) {
		ret = -1;
		pr_err("Failed unpacking object %p\n", pobj);
		goto err;
	}

	ret = 1;
err:
	if (buf != (void *)&local)
		xfree(buf);

	return ret;
}

/*
 * Writes PB record (header + packed object pointed by @obj)
 * to file @fd, using @getpksize to get packed size and @pack
 * to implement packing
 *
 *  0 on success
 * -1 on error
 */
int pb_write_one(int fd, void *obj, int type)
{
	u8 local[PB_PKOBJ_LOCAL_SIZE];
	void *buf = (void *)&local;
	u32 size, packed;
	int ret = -1;

	if (!cr_pb_descs[type].pb_desc) {
		pr_err("Wrong object requested %d\n", type);
		return -1;
	}

	size = cr_pb_descs[type].getpksize(obj);
	if (size > (u32)sizeof(local)) {
		buf = xmalloc(size);
		if (!buf)
			goto err;
	}

	packed = cr_pb_descs[type].pack(obj, buf);
	if (packed != size) {
		pr_err("Failed packing PB object %p\n", obj);
		goto err;
	}

	ret = write(fd, &size, sizeof(size));
	if (ret != sizeof(size)) {
		ret = -1;
		pr_perror("Can't write %d bytes", (int)sizeof(size));
		goto err;
	}

	ret = write(fd, buf, size);
	if (ret != size) {
		ret = -1;
		pr_perror("Can't write %d bytes", size);
		goto err;
	}

	ret = 0;
err:
	if (buf != (void *)&local)
		xfree(buf);
	return ret;
}

static int __collect_image(int fd_t, int obj_t, unsigned size,
		int (*collect)(void *obj, ProtobufCMessage *msg),
		void * (*alloc)(size_t size),
		void (*free)(void *ptr))
{
	int fd, ret;

	fd = open_image_ro(fd_t);
	if (fd < 0)
		return -1;

	while (1) {
		void *obj;
		ProtobufCMessage *msg;

		if (size) {
			ret = -1;
			obj = alloc(size);
			if (!obj)
				break;
		} else
			obj = NULL;

		ret = pb_read_one_eof(fd, &msg, obj_t);
		if (ret <= 0) {
			free(obj);
			break;
		}

		ret = collect(obj, msg);
		if (ret < 0) {
			free(obj);
			cr_pb_descs[obj_t].free(msg, NULL);
			break;
		}
	}

	close(fd);
	return ret;
}

int collect_image(int fd_t, int obj_t, unsigned size,
		int (*collect)(void *obj, ProtobufCMessage *msg))
{
	return __collect_image(fd_t, obj_t, size, collect, malloc, free);
}

int collect_image_sh(int fd_t, int obj_t, unsigned size,
		int (*collect)(void *obj, ProtobufCMessage *msg))
{
	return __collect_image(fd_t, obj_t, size, collect, shmalloc, shfree_last);
}