#include <stdio.h>

#include <stddef.h>

#include <string.h>

#include <sys/stat.h>

#include <sys/mman.h>

#include <fcntl.h>

#include <unistd.h>

#include <arpa/inet.h>

#include <rpm/rpmlib.h>

#include <zlib.h>

#include "razor.h"

#define	RPM_LEAD_SIZE 96

struct rpm_lead {

	unsigned char magic[4];

	unsigned char major;

	unsigned char minor;

	short type;

	short archnum;

	char name[66];

	short osnum;

	short signature_type;

	char reserved[16];

};

struct rpm_header {

	unsigned char magic[4];

	unsigned char reserved[4];

	int nindex;

	int hsize;

};

struct rpm_header_index {

	int tag;

	int type;

	int offset;

	int count;

};

struct properties {

	struct rpm_header_index *name;

	struct rpm_header_index *version;

	struct rpm_header_index *flags;

};

struct razor_rpm {

	struct rpm_header *signature;

	struct rpm_header *header;

	struct rpm_header_index *name;

	struct rpm_header_index *version;

	struct rpm_header_index *release;

	struct rpm_header_index *dirnames;

	struct rpm_header_index *dirindexes;

	struct rpm_header_index *basenames;

	struct rpm_header_index *filesizes;

	struct rpm_header_index *filemodes;

	struct rpm_header_index *filestates;

	const char **dirs;

	struct rpm_header_index *prein;

	struct rpm_header_index *postin;

	struct rpm_header_index *preun;

	struct rpm_header_index *postun;

	struct properties provides;

	struct properties requires;

	struct properties obsoletes;

	struct properties conflicts;

	const char *pool;

	void *map;

	size_t size;

	void *payload;

};

#define ALIGN(value, base) (((value) + (base - 1)) & ~((base) - 1))

static void

import_properties(struct razor_importer *importer,

		  struct properties *properties,

		  const char *pool, unsigned long type)

{

	const char *name, *version;

	int i, count;

	/* assert: count is the same for all arrays */

	if (properties->name == NULL)

		return;

	count = ntohl(properties->name->count);

	name = pool + ntohl(properties->name->offset);

	version = pool + ntohl(properties->version->offset);

	for (i = 0; i < count; i++) {

		razor_importer_add_property(importer, name, version, type);

		name += strlen(name) + 1;

		version += strlen(version) + 1;

	}

}

static void

import_files(struct razor_importer *importer, struct razor_rpm *rpm)

{

	const char *name;

	unsigned long *index;

	int i, count;

	char buffer[256];

	/* assert: count is the same for all arrays */

	if (rpm->dirnames == NULL)

		return;

	count = ntohl(rpm->basenames->count);

	index = (unsigned long *) (rpm->pool + ntohl(rpm->dirindexes->offset));

	name = rpm->pool + ntohl(rpm->basenames->offset);

	for (i = 0; i < count; i++) {

		snprintf(buffer, sizeof buffer,

			 "%s%s", rpm->dirs[ntohl(*index)], name);

		razor_importer_add_file(importer, buffer);

		name += strlen(name) + 1;

		index++;

	}

}

#define MAP_ENTRY(field, tag) { offsetof(struct razor_rpm, field), tag }

static struct index_map {

	unsigned int offset;

	unsigned int tag;

} index_map[] =	{

	MAP_ENTRY(prein, RPMTAG_PREIN),

	MAP_ENTRY(prein, RPMTAG_PREIN),

	MAP_ENTRY(postin, RPMTAG_POSTIN),

	MAP_ENTRY(preun, RPMTAG_PREUN),

	MAP_ENTRY(postun, RPMTAG_POSTUN),

	MAP_ENTRY(name, RPMTAG_NAME),

	MAP_ENTRY(version, RPMTAG_VERSION),

	MAP_ENTRY(release, RPMTAG_RELEASE),

	MAP_ENTRY(requires.name, RPMTAG_REQUIRENAME),

	MAP_ENTRY(requires.version, RPMTAG_REQUIREVERSION),

	MAP_ENTRY(requires.flags, RPMTAG_REQUIREFLAGS),

	MAP_ENTRY(provides.name, RPMTAG_PROVIDENAME),

	MAP_ENTRY(provides.version, RPMTAG_PROVIDEVERSION),

	MAP_ENTRY(provides.flags, RPMTAG_PROVIDEFLAGS),

	MAP_ENTRY(obsoletes.name, RPMTAG_OBSOLETENAME),

	MAP_ENTRY(obsoletes.version, RPMTAG_OBSOLETEVERSION),

	MAP_ENTRY(obsoletes.flags, RPMTAG_OBSOLETEFLAGS),

	MAP_ENTRY(conflicts.name, RPMTAG_CONFLICTNAME),

	MAP_ENTRY(conflicts.version, RPMTAG_CONFLICTVERSION),

	MAP_ENTRY(conflicts.flags, RPMTAG_CONFLICTFLAGS),

	MAP_ENTRY(dirindexes, RPMTAG_DIRINDEXES),

	MAP_ENTRY(basenames, RPMTAG_BASENAMES),

	MAP_ENTRY(dirnames, RPMTAG_DIRNAMES),

	MAP_ENTRY(filesizes, RPMTAG_FILESIZES),

	MAP_ENTRY(filemodes, RPMTAG_FILEMODES),

	MAP_ENTRY(filestates, RPMTAG_FILESTATES),

};

struct razor_rpm *

razor_rpm_open(const char *filename)

{

	struct razor_rpm *rpm;

	struct rpm_header_index *base, *index;

	struct stat buf;

	int fd, nindex, hsize, i, j, count;

	const char *name;

	rpm = malloc(sizeof *rpm);

	memset(rpm, 0, sizeof *rpm);

	if (stat(filename, &buf) < 0) {

		fprintf(stderr, "no such file %s (%m)\n", filename);

		return NULL;

	}

	fd = open(filename, O_RDONLY);

	if (fd < 0) {

		fprintf(stderr, "couldn't open %s\n", filename);

		return NULL;

	}

	rpm->size = buf.st_size;

	rpm->map = mmap(NULL, rpm->size, PROT_READ, MAP_PRIVATE, fd, 0);

	if (rpm->map == MAP_FAILED) {

		fprintf(stderr, "couldn't mmap %s\n", filename);

		return NULL;

	}

	close(fd);

	rpm->signature = rpm->map + RPM_LEAD_SIZE;

	nindex = ntohl(rpm->signature->nindex);

	hsize = ntohl(rpm->signature->hsize);

	rpm->header = (void *) (rpm->signature + 1) +

		ALIGN(nindex * sizeof *index + hsize, 8);

	nindex = ntohl(rpm->header->nindex);

	hsize = ntohl(rpm->header->hsize);

	rpm->payload = (void *) (rpm->header + 1) +

		nindex * sizeof *index + hsize;

	base = (struct rpm_header_index *) (rpm->header + 1);

	rpm->pool = (void *) base + nindex * sizeof *index;

	for (i = 0; i < nindex; i++) {

		index = base + i;

		for (j = 0; j < ARRAY_SIZE(index_map); j++) {

			struct rpm_header_index **p;

			if (index_map[j].tag == ntohl(index->tag)) {

				p = (void *) rpm + index_map[j].offset;

				*p = index;

			}

		}				 

	}

	/* Look up dir names now so we can index them directly. */

	if (rpm->dirnames != NULL) {

		count = ntohl(rpm->dirnames->count);

		rpm->dirs = calloc(count, sizeof *rpm->dirs);

		name = rpm->pool + ntohl(rpm->dirnames->offset);

		for (i = 0; i < count; i++) {

			rpm->dirs[i] = name;

			name += strlen(name) + 1;

		}

	}

	return rpm;

}

struct cpio_file_header {

	char magic[6];

	char inode[8];

	char mode[8];

	char uid[8];

	char gid[8];

	char nlink[8];

	char mtime[8];

	char filesize[8];

	char devmajor[8];

	char devminor[8];

	char rdevmajor[8];

	char rdevminor[8];

	char namesize[8];

	char checksum[8];

	char filename[0];

};

/* gzip flags */

#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */

#define HEAD_CRC     0x02 /* bit 1 set: header CRC present */

#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */

#define ORIG_NAME    0x08 /* bit 3 set: original file name present */

#define COMMENT      0x10 /* bit 4 set: file comment present */

#define RESERVED     0xE0 /* bits 5..7: reserved */

static int

create_path(const char *root, const char *path,

	    const char *name, unsigned mode, int *fd)

{

	char buffer[256], *p;

	const char *slash, *next;

	struct stat buf;

	/* Create all sub-directories in dir and then create name. We

	 * know root exists and is a dir, root does not end in a '/',

	 * and path has a leading '/'. */

	strcpy(buffer, root);

	p = buffer + strlen(buffer);

	slash = path;

	for (slash = path; slash[1] != '\0'; slash = next) {

		next = strchr(slash + 1, '/');

		memcpy(p, slash, next - slash);

		p += next - slash;

		*p = '\0';

		if (stat(buffer, &buf) == 0) {

			if (!S_ISDIR(buf.st_mode)) {

				fprintf(stderr,

					"%s exists but is not a directory\n",

					buffer);

				return -1;

			}

		} else if (mkdir(buffer, 0777) < 0) {

			fprintf(stderr, "failed to make directory %s: %m\n",

				buffer);

			return -1;

		}

		/* FIXME: permissions */

	}

	*p++ = '/';

	strcpy(p, name);

	switch (mode >> 12) {

	case REG:

	default:

		*fd = open(buffer, O_WRONLY | O_CREAT | O_TRUNC, mode & 0x1ff);

		return *fd;

	case XDIR:

		*fd = -1;

		return mkdir(buffer, mode & 0x1ff);

	}

}

int

razor_rpm_install(struct razor_rpm *rpm, const char *root)

{

	z_stream stream;

	unsigned char payload[32768], *gz_header;

	char buffer[256];

	int err, method, flags, count, i, fd, written;

	struct cpio_file_header *header;

	unsigned long *size, *index, rest, length;

	unsigned short *mode;

	const char *name, *dir;

	struct stat buf;

	if (stat(root, &buf) < 0 || !S_ISDIR(buf.st_mode)) {

		fprintf(stderr,

			"root installation directory \"%s\" does not exist\n",

			root);

		return -1;

	}

	gz_header = rpm->payload;

	if (gz_header[0] != 0x1f || gz_header[1] != 0x8b) {

		fprintf(stderr, "payload section doesn't have gz header\n");

		return -1;

	}

	method = gz_header[2];

	flags = gz_header[3];

	if (method != Z_DEFLATED || flags != 0) {

		fprintf(stderr,

			"unknown payload compression method or flags set\n");

		return -1;

	}

	stream.zalloc = NULL;

	stream.zfree = NULL;

	stream.opaque = NULL;

	stream.next_in  = gz_header + 10;

	stream.avail_in = (rpm->map + rpm->size) - (void *) stream.next_in;

	stream.next_out = NULL;

	stream.avail_out = 0;

	err = inflateInit2(&stream, -MAX_WBITS);

	if (err != Z_OK) {

		fprintf(stderr, "inflateInit error: %d\n", err);

		return -1;

	}

	count = ntohl(rpm->basenames->count);

	size = (unsigned long *) (rpm->pool + ntohl(rpm->filesizes->offset));

	index = (unsigned long *) (rpm->pool + ntohl(rpm->dirindexes->offset));

	mode = (unsigned short *) (rpm->pool + ntohl(rpm->filemodes->offset));

	name = rpm->pool + ntohl(rpm->basenames->offset);

	for (i = 0; i < count; i++) {

		dir = rpm->dirs[ntohl(*index)];

		snprintf(buffer, sizeof buffer, "%s%s", dir, name);

		stream.next_out = payload;

		/* Plus two for the leading '.' and the terminating NUL. */

		stream.avail_out =

			ALIGN(sizeof *header + strlen(buffer) + 2, 4);

		err = inflate(&stream, Z_SYNC_FLUSH);

		if (err != Z_OK) {

			fprintf(stderr, "inflate error: %d\n", err);

			return -1;

		}

		header = (struct cpio_file_header *) payload;

		/* FIXME: Figure out if it's a symlink, device file,

		 * directorys or whatever.  Maybe do this upfront. */

		if (create_path(root, dir, name, ntohs(*mode), &fd) < 0)

			return -1;

		if (ntohs(*mode) >> 12 == XDIR)

			rest = 0;

		else

			rest = ntohl(*size);

		while (rest > 0) {

			if (ALIGN(rest, 4) > sizeof payload)

				length = sizeof payload;

			else

				length = rest;

			stream.next_out = payload;

			stream.avail_out = ALIGN(length, 4);

			err = inflate(&stream, Z_SYNC_FLUSH);

			if (err != Z_OK && err != Z_STREAM_END) {

				fprintf(stderr,

					"inflate error: %d (%m)\n", err);

				return -1;

			}

			rest -= length;

			stream.next_out = payload;

			while (length > 0) {

				written = write(fd, stream.next_out, length);

				if (written < 0) {

					fprintf(stderr, "write error: %m\n");

					return -1;

				}

				length -= written;

			}

		}

		if (fd > 0 && close(fd) < 0) {

			fprintf(stderr, "failed to close \"%s/%s%s\": %m\n",

				root, dir, name);

			return -1;

		}

		name += strlen(name) + 1;

		index++;

		size++;

		mode++;

	}

	err = inflateEnd(&stream);

	if (err != Z_OK) {

		fprintf(stderr, "inflateEnd error: %d\n", err);

		return -1;

	}	    

	return 0;

}

int

razor_rpm_close(struct razor_rpm *rpm)

{

	int err;

	free(rpm->dirs);

	err = munmap(rpm->map, rpm->size);

	free(rpm);

	return err;

}

int

razor_importer_add_rpm(struct razor_importer *importer, struct razor_rpm *rpm)

{

	razor_importer_begin_package(importer,

				     rpm->pool + ntohl(rpm->name->offset),

				     rpm->pool + ntohl(rpm->version->offset));

	import_properties(importer, &rpm->requires,

			  rpm->pool, RAZOR_PROPERTY_REQUIRES);

	import_properties(importer, &rpm->provides,

			  rpm->pool, RAZOR_PROPERTY_PROVIDES);

	import_properties(importer, &rpm->conflicts,

			  rpm->pool, RAZOR_PROPERTY_CONFLICTS);

	import_properties(importer, &rpm->obsoletes,

			  rpm->pool, RAZOR_PROPERTY_OBSOLETES);

	import_files(importer, rpm);

	razor_importer_finish_package(importer);

	return 0;

}