/*
 *  ncpmount.c
 *
 *  Copyright (C) 1995 by Volker Lendecke
 *
 */

#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/stat.h>
#include <sys/types.h>
/* #include <sys/wait.h> */  /* generates a warning here */
extern pid_t waitpid(pid_t, int *, int);
#include <sys/errno.h>
#include <sys/time.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <mntent.h>
#include <linux/ipx.h>

#include <linux/fs.h>
#include <linux/ncp.h>
#include <linux/ncp_fs.h>
#include <linux/ncp_mount.h>
#include "ipxutil.h"

static char *progname;


static void
str_upper(char *name)
{
	while (*name)  {
		*name = toupper(*name);
		name = name + 1;
	}
}

static char *
fullpath(const char *p)
{
        char path[MAXPATHLEN];

        if (realpath(p, path) == NULL)
                return strdup(p);
        else
                return strdup(path);
}

static void
usage(void)
{
	printf("usage: %s server mount-point [options]\n", progname);
        printf("Try `%s -h' for more information\n", progname);
}

static void
help(void)
{
        printf("\n");
        printf("usage: %s server mount-point [options]\n", progname);
        printf("\n"
               "-U username    Username sent to server\n"
               "-u uid         uid the mounted files get\n"
               "-g gid         gid the mounted files get\n"
               "-f mode        permission the files get (octal notation)\n"
               "-d mode        permission the dirs get (octal notation)\n"
               "-C             Don't convert password to uppercase\n"
               "-P password    Use this password\n"
               "-n             Do not use any password\n"
               "               If neither -P nor -n are given, you are\n"
               "               asked for a password.\n"
               "-h             print this help text\n"
               "\n");
}

struct sap_query {
	unsigned short query_type; /* net order */
	unsigned short server_type; /* net order */
};

struct sap_server_ident {
	unsigned short server_type          __attribute__ ((packed));
	char           server_name[48]      __attribute__ ((packed));
	IPXNet         server_network       __attribute__ ((packed));
	IPXNode        server_node          __attribute__ ((packed));
	IPXPort        server_port          __attribute__ ((packed));
	unsigned short intermediate_network __attribute__ ((packed));
};
       
void
ipx_fprint_node(FILE* file,IPXNode node)
{
	fprintf(file,"%02X%02X%02X%02X%02X%02X",
		(unsigned char)node[0],
		(unsigned char)node[1],
		(unsigned char)node[2],
		(unsigned char)node[3],
		(unsigned char)node[4],
		(unsigned char)node[5]
		);
}

void
ipx_fprint_network(FILE* file,IPXNet net)
{
	fprintf(file,"%08lX",ntohl(net));
}

void
ipx_fprint_port(FILE* file,IPXPort port)
{
	fprintf(file,"%04X",ntohs(port));
}

void
ipx_fprint_saddr(FILE* file,struct sockaddr_ipx* sipx)
{
	ipx_fprint_network(file,sipx->sipx_network);
	fprintf(file,":");
	ipx_fprint_node(file,sipx->sipx_node);
	fprintf(file,":");
	ipx_fprint_port(file,sipx->sipx_port);
}

void
ipx_print_node(IPXNode node)
{
	ipx_fprint_node(stdout,node);
}

void
ipx_print_network(IPXNet net)
{
	ipx_fprint_network(stdout,net);
}

void
ipx_print_port(IPXPort port)
{
	ipx_fprint_port(stdout,port);
}

void
ipx_print_saddr(struct sockaddr_ipx* sipx)
{
	ipx_fprint_saddr(stdout,sipx);
}

int
ipx_sap_find_server(char *name, int server_type, int timeout,
		    struct sockaddr_ipx *result)
{
	struct sockaddr_ipx ipxs;
	char data[1024];
	int sock;
	int opt;
	int res = -1;
	int name_len = strlen(name);
	fd_set rd, wr, ex;
	struct timeval tv;

	if (name_len > 48) {
		return -1;
	}

	sock=socket(AF_IPX,SOCK_DGRAM,PF_IPX);
	if (sock==-1) {
		return -1;
	}
	
	opt=1;
	/* Permit broadcast output */
	if(setsockopt(sock,SOL_SOCKET,SO_BROADCAST, &opt,sizeof(opt))==-1)
	{
		perror("setsockopt");
		goto finished;
	}
	
	memset(&ipxs, 0, sizeof(ipxs));
	ipxs.sipx_family=AF_IPX;
	ipxs.sipx_network=htonl(0x0);
	ipxs.sipx_port=htons(0x0);
	ipxs.sipx_type=IPX_SAP_PTYPE;
	
	if(bind(sock,(struct sockaddr*)&ipxs,sizeof(ipxs))==-1)
	{
		perror("bind");
		goto finished;
	}
	
	*(unsigned short *)data = htons(0x0001);
	*(unsigned short *)&(data[2]) = htons(server_type);
	
	memset(&ipxs, 0, sizeof(ipxs));
	ipxs.sipx_family=AF_IPX;
	ipxs.sipx_network=htonl(0x0);
	ipx_assign_node(ipxs.sipx_node, IPX_BROADCAST_NODE);
	ipxs.sipx_port=htons(IPX_SAP_PORT);
	ipxs.sipx_type=IPX_SAP_PTYPE;
	
	if (sendto(sock, data, 4, 0,
		   (struct sockaddr *)&ipxs, sizeof(ipxs)) < 0) {
		perror("sendto");
		goto finished;
	}
	
	FD_ZERO(&rd); FD_ZERO(&wr); FD_ZERO(&ex);
	FD_SET(sock, &rd);
	
	tv.tv_sec = timeout;
	tv.tv_usec = 0;
	
	if (select(sock+1, &rd, &wr, &ex, &tv) == -1) {
		perror("select");
		goto finished;
	}
	
	if (FD_ISSET(sock, &rd)) {
		int len = recv(sock, data, 1024, 0);
		int i;
		struct sap_server_ident *ident;
		
		for (i = 2; i < len; i += 64) {
			ident = (struct sap_server_ident *)(data+i);
			if (   (strncmp(name,ident->server_name,name_len)==0)
			    && (name_len < 48)
			    && (ident->server_name[name_len] == '\0'))
			{
				result->sipx_family  = AF_IPX;
				result->sipx_network =
					ident->server_network;
				result->sipx_port    = ident->server_port;
				ipx_assign_node(result->sipx_node,
						ident->server_node);
				res = 0;
				goto finished;
			}
		}
	}

 finished:
	close(sock);
	return res;
}

int
ipx_sscanf_node(char *buf, unsigned char node[6])
{
	int i;
	int n[6];

	if ((i = sscanf(buf, "%2x%2x%2x%2x%2x%2x",
			&(n[0]), &(n[1]), &(n[2]),
			&(n[3]), &(n[4]), &(n[5]))) != 6) {
								  return i;
							  }

	for (i=0; i<6; i++) {
				    node[i] = n[i];
			    }
	return 6;
}

static int
parse_args(int argc, char *argv[], struct ncp_mount_data *data,
           int *got_password, int *upcase_password)
{
        int opt;
        struct passwd *pwd;
        struct group  *grp;

        *got_password = 0;
        *upcase_password = 1;

        while ((opt = getopt (argc, argv, "Cp:s:c:U:u:g:f:d:m:P:n")) != EOF) {
                switch (opt) {
                case 'C':
                        *upcase_password = 0;
                        break;
                case 'U':
                        if (strlen(optarg) > 63) {
                                fprintf(stderr, "Username too long: %s\n",
                                        optarg);
                                return 1;
                        }
                        strcpy(data->username, optarg);
                        break;
                case 'u':
                        if (isdigit(optarg[0])) {
                                data->uid = atoi(optarg);
                        } else {
                                pwd = getpwnam(optarg);
                                if (pwd == NULL) {
                                        fprintf(stderr, "Unknown user: %s\n",
                                                optarg);
                                        return 1;
                                }
                                data->uid = pwd->pw_uid;
                        }
                        break;
                case 'g':
                        if (isdigit(optarg[0])) {
                                data->gid = atoi(optarg);
                        } else {
                                grp = getgrnam(optarg);
                                if (grp == NULL) {
                                        fprintf(stderr, "Unknown group: %s\n",
                                                optarg);
                                        return 1;
                                }
                                data->gid = grp->gr_gid;
                        }
                        break;
                case 'f':
                        data->file_mode = strtol(optarg, NULL, 8);
                        break;
                case 'd':
                        data->dir_mode = strtol(optarg, NULL, 8);
                        break;
                case 'P':
                        strcpy(data->password, optarg);
                        *got_password = 1;
                        break;
                case 'n':
			data->password[0] = '\0';
                        *got_password = 1;
                        break;
                default:
                        return -1;
                }
        }
        return 0;
        
}

/* Returns 0 if the filesystem is in the kernel after this routine
   completes */
static int
load_ncpfs()
{
	FILE *fver, *ffs;
	char s[1024];
	char modname[1024];
	char *p, *p1;
        pid_t pid;
        int status;

	/* Check if ncpfs is in the kernel */
	ffs = fopen("/proc/filesystems", "r");
	if (ffs == NULL) {
		perror("Error: \"/proc/filesystems\" could not be read:");
		return -1;
	}
	p = NULL;
	while (! feof(ffs)) {
		p1 = fgets(s, sizeof(s), ffs);
		if (p1) {
			p = strstr(s, "ncpfs");
			if (p) {
				break;
			}
		}
	}
	fclose(ffs);
	if (p) {
		return 0;
	}
	fver = fopen("/proc/version", "r");
	if (fver == NULL) {
		perror("Error: \"/proc/version\" could not be read:");
		return -1;
	}
	fgets(s, 1024, fver);
	fclose(fver);
	p = strstr(s, "version ");
	if (p == NULL) {
	version_error:
		fprintf(stderr, "Error: Unable to determine the Linux version"
                        "from \"/proc/version\n");
		return -1;
	}
        p = strchr(p, ' ') + 1;
	p1 = strchr(p, ' ');
	if (p1 == NULL)  {
		goto version_error;
	}
        strcpy(modname, "/lib/modules/");
        strncat(modname, p, p1 - p);
        strcat(modname, "/ncpfs.o");

        /* system() function without signal handling, from Stevens */

        if ((pid = fork()) < 0) {
                return 1;
        } else if (pid == 0) {
                /* child */
                execl("/sbin/insmod", "insmod", modname, NULL);
                _exit(127);     /* execl error */
        } else {
                /* parent */
                while (waitpid(pid, &status, 0) < 0) {
                        if (errno != EINTR) {
                                status = -1;
                                break;
                        }
                }
        }
        return status;
}

/* Check whether user is allowed to mount on the specified mount point */
static int
mount_ok(struct stat *st)
{
        if (!S_ISDIR(st->st_mode))
        {
                errno = ENOTDIR;
                return -1;
        }
	
        if (   (getuid() != 0)
            && (   (getuid() != st->st_uid)
                || ((st->st_mode & S_IRWXU) != S_IRWXU)))
        {
                errno = EPERM;
                return -1;
        }

        return 0;
}



int 
main(int argc, char *argv[])
{
        struct ncp_mount_data data;
	struct sockaddr_ipx addr;
        struct stat st;

        int fd;
        int Got_Password;
        int Upcase_Password;
        int um;
	unsigned int flags;
	char hostname[MAXHOSTNAMELEN + 1];

        char *server_name;
        char *mount_point;

        struct mntent ment;
        FILE *mtab;

	int ncp_sock, wdog_sock;

        progname = argv[0];

        if (geteuid() != 0) {
                fprintf(stderr, "%s must be installed suid root\n", progname);
                exit(1);
        }

	memset(&data, 0, sizeof(struct ncp_mount_data));

	memset(hostname, '\0', MAXHOSTNAMELEN+1);
	gethostname(hostname, MAXHOSTNAMELEN);

        if (argc < 3) {
                if (   (argc == 2)
                    && (argv[1][0] == '-')
                    && (argv[1][1] == 'h')
                    && (argv[1][2] == '\0')) {

                        help();
                        return 0;
                }
                else
                {
                        usage();
                        return -1;
                }
        }

        server_name = argv[1];
        mount_point = argv[2];

        argv += 2;
        argc -= 2;

        if (stat(mount_point, &st) == -1) {
                fprintf(stderr, "could not find mount point %s: %s\n",
                        mount_point, strerror(errno));
                exit(1);
        }

        if (mount_ok(&st) != 0) {
                fprintf(stderr, "cannot to mount on %s: %s\n",
                        mount_point, strerror(errno));
                exit(1);
        }

	ncp_sock  = socket(AF_IPX, SOCK_DGRAM, PF_IPX);
	if (ncp_sock == -1) {
		fprintf(stderr, "could not open ncp socket: %s\n",
			strerror(errno));
		exit(1);
	}

	wdog_sock = socket(AF_IPX, SOCK_DGRAM, PF_IPX);
	if (wdog_sock == -1) {
		fprintf(stderr, "could not open wdog socket: %s\n",
			strerror(errno));
		exit(1);
	}

	addr.sipx_type = NCP_PTYPE;

	if (bind(ncp_sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
		fprintf(stderr, "bind(ncp_sock, ): %s\n",
			strerror(errno));
		exit(1);
	}

	if (bind(wdog_sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
		fprintf(stderr, "bind(wdog_sock, ): %s\n",
			strerror(errno));
		exit(1);
	}

	if (ipx_sap_find_server(server_name, IPX_SAP_FILE_SERVER,
				3, &addr) != 0) {
		fprintf(stderr, "could not find server %s\n", server_name);
		exit(1);
	}

	/* Check if the ncpfs filesystem is in the kernel.  If not, attempt
	 * to load the ncpfs module */
	if (load_ncpfs() != 0) {
		fprintf(stderr, "Error: Unable to start ncpfs, exiting...\n");
		exit(1);
	}

	data.version      = NCP_MOUNT_VERSION;
	data.ncp_fd       = ncp_sock;
	data.wdog_fd      = wdog_sock;
	data.mounted_uid  = getuid();
	data.serv_addr    = addr;
	strcpy(data.server_name, server_name);
	data.time_out     = 20;	/* 2 seconds */
	data.retry_count  = 2;

        /* getuid() gives us the real uid, who may umount the fs */
        data.mounted_uid = getuid();

        if (getenv("USER")) {
                strcpy(data.username, getenv("USER"));
                str_upper(data.username);
        }

        if (data.username[0] == 0 && getenv("LOGNAME"))
        {
                strcpy(data.username,getenv("LOGNAME"));
                str_upper(data.username);
        }

        data.uid = getuid();
        data.gid = getgid();
        um = umask(0);
        umask(um);
        data.file_mode = (S_IRWXU|S_IRWXG|S_IRWXO) & ~um;
        data.dir_mode  = 0;

        if (parse_args(argc, argv, &data, &Got_Password,
                       &Upcase_Password) != 0) {
                usage();
                return -1;
        }

        if (data.dir_mode == 0) {
                data.dir_mode = data.file_mode;
                if ((data.dir_mode & S_IRUSR) != 0)
                        data.dir_mode |= S_IXUSR;
                if ((data.dir_mode & S_IRGRP) != 0)
                        data.dir_mode |= S_IXGRP;
                if ((data.dir_mode & S_IROTH) != 0)
                        data.dir_mode |= S_IXOTH;
        }

        if (Got_Password == 0) {
                strcpy(data.password, getpass("Password: "));
        }

        if (Upcase_Password == 1) {
                str_upper(data.password);
        }

        if (data.server_name[0] == '\0') {
                strcpy(data.server_name, server_name);
                str_upper(data.server_name);
        }

	flags = MS_MGC_VAL;

	if (mount(NULL, mount_point, "ncpfs",
                  flags, (char *)&data) < 0) {
		perror("mount error");
	        close(wdog_sock);
		close(ncp_sock);
                printf("Maybe you should try to type the username and\n"
                       "password in UPPERCASE.\n");
		return -1;
	}

	close(ncp_sock);
	close(wdog_sock);

        ment.mnt_fsname = server_name;
        ment.mnt_dir = fullpath(mount_point);
        ment.mnt_type = "ncpfs";
        ment.mnt_opts = "rw";
        ment.mnt_freq = 0;
        ment.mnt_passno= 0;

        mount_point = ment.mnt_dir;
	
        if ((fd = open(MOUNTED"~", O_RDWR|O_CREAT|O_EXCL, 0600)) == -1)
        {
                fprintf(stderr, "Can't get "MOUNTED"~ lock file");
                return 1;
        }
        close(fd);
	
        if ((mtab = setmntent(MOUNTED, "a+")) == NULL)
        {
                fprintf(stderr, "Can't open " MOUNTED);
                return 1;
        }

        if (addmntent(mtab, &ment) == 1)
        {
                fprintf(stderr, "Can't write mount entry");
                return 1;
        }
        if (fchmod(fileno(mtab), 0644) == -1)
        {
                fprintf(stderr, "Can't set perms on "MOUNTED);
                return 1;
        }
        endmntent(mtab);

        if (unlink(MOUNTED"~") == -1)
        {
                fprintf(stderr, "Can't remove "MOUNTED"~");
                return 1;
        }

	return 0;
}