/*
 * @(#CDWrootGate.cpp
 *
 * This file is part of webCDwriter - Network CD/DVD Writing.
 *
 * Copyright (C) 2003-2005 Jörg P. M. Haeger
 *
 * webCDwriter is free software. See CDWserver.cpp for details.
 *
 * Author: Jörg P. M. Haeger, 11.10.2003
 */

#include <errno.h>
#include <sys/types.h>
#include <sched.h>
#include <stdio.h>
#include <string.h>
#ifdef FreeBSD
#include <sys/param.h>
#endif
#include <sys/mount.h>
#include <sys/stat.h>
#include <unistd.h>
#include "config.h"
#include "Error.h"
#include "Version.h"

#ifdef PAM
#include "PAM.h"
#endif

/**
 * Services for webCDwriter
 *
 * @version 20051018
 * @author Jörg P. M. Haeger
 */
class CDWrootGate {
	public: CDWrootGate() {
	}

	public: static void listIDEDevices() {
		char driver[1024];
		for (char ch = 'a'; ch <= 'z'; ch++) {
			const char *media = readMedia(ch);

			sprintf(driver, "/proc/ide/hd%c/driver", ch);
			FILE *in = fopen(driver, "r");
			if (in == NULL)
				continue;
			if (fgets(driver, sizeof driver, in) == NULL)
				strcpy(driver, "unknown");
			fclose(in);

			removeLF(driver);
			printf("/dev/hd%c %s %s\n", ch, media, driver);
		}
	}

	public: static int main(int argc, char *args[]) {
		printf("CDWrootGate %s (part of %s)\n", version, project);
		fflush(stdout);

		CDWrootGate *app = new CDWrootGate();
		try {
			app->scanArgs(argc, args);
		}
		catch (Error *error) {
			printf("error: %s\n", error->toString());
			delete error;
			return 1;
		}
		return 0;
	}

	public: static void prepareDevice(const char *dev, int uid) {
		char ch, ch2;
		const char *media = "";
		if (sscanf(dev, "/dev/cd%c", &ch) == 1)
			media = "cdrom";
		else
		if (sscanf(dev, "/dev/hd%c%c", &ch, &ch2) == 1)
			media = readMedia(ch);
		else
		if (sscanf(dev, "/dev/scd%c", &ch) == 1
				|| sscanf(dev, "/dev/sr%c", &ch) == 1)
			media = "cdrom";
		else
			throw new Error("Illegal device %s", dev);

		if (strcmp(media, "cdrom") != 0)
			throw new Error("Device %s is not a cdrom", dev);

		struct stat statBuf;
		if (stat(dev, &statBuf) != 0)
			throw new Error("Cannot stat device %s", dev);

		if (chown(dev, uid, statBuf.st_gid) != 0)
			throw new Error("Cannot change owner of %s", dev);

		statBuf.st_mode = S_IRUSR | S_IWUSR;
		chmod(dev, statBuf.st_mode);

		if (strstr(dev, "/dev/cd") == dev) {
			char dev2[1024];
			sprintf(dev2, "/dev/pass%c", ch);
			if (stat(dev2, &statBuf) == 0)
				if (chown(dev2, uid, statBuf.st_gid) == 0) {
					statBuf.st_mode |= S_IRUSR | S_IWUSR;
					chmod(dev2, statBuf.st_mode);
				}
		}
	}

	protected: static const char *readMedia(char ch) {
		static char media[1024];
		sprintf(media, "/proc/ide/hd%c/media", ch);
		FILE *in = fopen(media, "r");
		if (in == NULL) {
			strcpy(media, "unknown");
			return media;
		}
		if (fgets(media, sizeof media, in) != NULL)
			removeLF(media);
		fclose(in);
		return media;
	}

	public: static void removeLF(char *str) {
		for (int i = 0; str[i] != 0; i++)
			if (str[i] == '\n')
				str[i] = 0;
	}

	public: static void reserve(const char *device) {
		const char MTAB[] = "/etc/mtab";
		const char MTAB_TMP[] = "/etc/mtab.webCDwriter";
		FILE *in = fopen(MTAB, "r");
		if (in == NULL)
			return;

		FILE *out = fopen(MTAB_TMP, "w");
		if (out == NULL) {
			fclose(in);
			return;
		}

		while (true) {
			char line[1024 + 1], dev[1024 + 2], dir[1024 + 2];
			if (fgets(line, sizeof line, in) == NULL)
				break;
			removeLF(line);
			int i = 0;
			for (; i < sizeof line && line[i] > 32; i++)
				dev[i] = line[i];
			dev[i] = 0;
			while (i < sizeof line && line[i] <= 32)
				i++;
			int j = 0;
			for (; i < sizeof line && line[i] > 32; i++, j++)
				dir[j] = line[i];
			dir[j] = 0;
			if (strcmp(dev, device) != 0)
				fprintf(out, "%s\n", line);
		}
		fprintf(out, "%s %s iso9660 ro,noexec,nosuid 0 0\n",
			device, mntDir);
		fclose(out);
		fclose(in);

		struct stat statBuf;
		if (lstat(MTAB, &statBuf) == 0 && !S_ISLNK(statBuf.st_mode)) {
			chown(MTAB_TMP, statBuf.st_uid, statBuf.st_gid);
			chmod(MTAB_TMP, statBuf.st_mode);
			rename(MTAB_TMP, MTAB);
		}
	}

#ifdef PAM
	public: static void runPAM() {
		printf("User: ");
		fflush(stdout);
		char user[1024];
		fgets(user, sizeof user, stdin);
		for (int i = 0; i < sizeof user; i++)
			if (user[i] == '\n')
				user[i] = 0;

		printf("Password: ");
		fflush(stdout);
		char passwd[1024];
		fgets(passwd, sizeof passwd, stdin);
		for (int i = 0; i < sizeof passwd; i++)
			if (passwd[i] == '\n')
				passwd[i] = 0;

		PAM4CDWserver server;
		try {
			server.check(user, passwd);
			printf("%s authenticated\n", user);
		}
		catch (Exception *exception) {
			throw new Error(exception->toString());
		}
	}
#endif

	protected: void scanArgs(int argc, char *args[]) {
		if (argc < 2) {
			showUsage(args[0]);
			return;
		}

		if (strcmp(args[1], "listIDEDevices") == 0) {
			listIDEDevices();
		}
#ifdef PAM
		else
		if (strcmp(args[1], "pam") == 0
				|| strcmp(args[1], "-pam") == 0) {
			runPAM();
		}
#endif
		else
		if (strcmp(args[1], "prepareDevice") == 0) {
			int uid;
			if (argc != 4 || sscanf(args[3], "%d", &uid) != 1)
				showUsage(args[0]);
			else {
				prepareDevice(args[2], uid);
				unmount(args[2]);
			}
		}
		else
		if (strcmp(args[1], "-scsi") == 0) {
/*			FILE *out = fopen("/proc/scsi/scsi", "w");
			if (out != NULL) {
				fprintf(out, "scsi remove-single-device 0 0 0 0\n");
				fclose(out);
			}
			out = fopen("/proc/scsi/scsi", "w");
			if (out != NULL) {
				fprintf(out, "scsi add-single-device 0 0 0 0\n");
				fclose(out);
			}
*/
		}
		else
		if (strcmp(args[1], "setScheduler") == 0) {
			int pid, pri;
			if (argc != 5
					|| sscanf(args[2], "%d", &pid) != 1
					|| (strcmp(args[3], "FIFO") != 0
						&& strcmp(args[3], "RR") != 0
						&& strcmp(args[3], "OTHER") != 0)
					|| sscanf(args[4], "%d", &pri) != 1) {
				printf("Usage: %s setScheduler"
					" pid [FIFO | RR | OTHER] priority\n",
					args[0]);
				return;
			}
			setScheduler(pid, args[3], pri);
		}
		else
		if (strcmp(args[1], "unmount") == 0) {
			if (argc != 3)
				showUsage(args[0]);
			else
				unmount(args[2]);
		}
		else
			showUsage(args[0]);
	}

	public: static void setScheduler(int pid, char *type, int pri) {
		int policy = SCHED_OTHER;
		if (strcmp(type, "FIFO") == 0)
			policy = SCHED_FIFO;
		else
		if (strcmp(type, "RR") == 0)
			policy = SCHED_RR;

		struct sched_param schedParam;
		sched_getparam(pid, &schedParam);

		int oldPolicy = sched_getscheduler(pid);
		if (oldPolicy < 0)
			throw new Error("pid %d does not exists!\n", pid);

		printf("old: scheduler %d, priority %d\n",
			oldPolicy, schedParam.sched_priority);

		schedParam.sched_priority = pri;
		if (sched_setscheduler(pid, policy, &schedParam) < 0)
			throw new Error("Cannot set %s, priority %d.\n", type, pri);

		sched_getparam(pid, &schedParam);
		printf("new: scheduler %d, priority %d\n",
			sched_getscheduler(pid), schedParam.sched_priority);
	}

	public: static void showUsage(const char *arg0) {
		printf("\n%s offers some services that need root privileges\n\n"
			"Usage:\n"
			"\t%s listIDEDevices\n",
			arg0, arg0);
#ifdef PAM
		printf("\t%s pam\n", arg0);
#endif
		printf(
			"\t%s prepareDevice DEVICE UID\n"
			"\t%s setScheduler pid [FIFO | RR | OTHER] priority\n"
			"\t%s unmount DEVICE\n"
			"\n",
			arg0, arg0, arg0);
	}

	public: static void unmount(const char *device) {
		char ch, ch2;
		const char *media = "";
		if (sscanf(device, "/dev/cd%c", &ch) == 1)
			media = "cdrom";
		else
		if (sscanf(device, "/dev/hd%c%c", &ch, &ch2) == 1)
			media = readMedia(ch);
		else
		if (sscanf(device, "/dev/scd%c", &ch) == 1
				|| sscanf(device, "/dev/sr%c", &ch) == 1)
			media = "cdrom";
		else
			throw new Error("Illegal device %s", device);

		if (strcmp(media, "cdrom") != 0)
			throw new Error("Device %s is not a cdrom", device);

		FILE *in = fopen("/proc/mounts", "r");
		if (in == NULL)
			throw new Error("Cannot read /proc/mounts");

		while (true) {
			char line[1024 + 1], dev[1024 + 2], dir[1024 + 2];
			if (fgets(line, sizeof line, in) == NULL)
				break;
			int i = 0;
			for (; i < sizeof line && line[i] > 32; i++)
				dev[i] = line[i];
			dev[i] = 0;
			while (i < sizeof line && line[i] <= 32)
				i++;
			int j = 0;
			for (; i < sizeof line && line[i] > 32; i++, j++)
				dir[j] = line[i];
			dir[j] = 0;
			if (strcmp(dev, device) == 0) {
				int res;
#ifdef FreeBSD
				res = ::unmount(dir, MNT_FORCE);
#else
				res = ::umount(dir);
#endif
				if (res != 0)
					throw new Error("Cannot unmount %s: %s\n",
						dev, strerror(errno));
			}
		}
		fclose(in);

//		reserve(device);
	}
};

int main(int argc, char *args[]) {
	return CDWrootGate::main(argc, args);
}