/* 
   Mount helper utility for Linux CIFS VFS (virtual filesystem) client
   Copyright (C) 2003 Steve French  (sfrench@us.ibm.com)

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <pwd.h>
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <getopt.h>
#include <errno.h>
#include <netdb.h>
#include <string.h>
#include <mntent.h>
#include <fcntl.h>

#define MOUNT_CIFS_VERSION_MAJOR "1"
#define MOUNT_CIFS_VERSION_MINOR "0"

#ifndef MOUNT_CIFS_VENDOR_SUFFIX
#define MOUNT_CIFS_VENDOR_SUFFIX ""
#endif

char * thisprogram;
int verboseflag = 0;
static int got_password = 0;
static int got_user = 0;
static int got_domain = 0;
static int got_ip = 0;
static int got_unc = 0;
static int got_uid = 0;
static int got_gid = 0;
static char * user_name = NULL;
char * mountpassword = NULL;


/* BB finish BB

        cifs_umount
        open nofollow - avoid symlink exposure? 
        get owner of dir see if matches self or if root
        call system(umount argv) etc.
                
BB end finish BB */

static void mount_cifs_usage(void)
{
	printf("\nUsage:  %s <remotetarget> <dir> -o <options>\n", thisprogram);
	printf("\nMount the remote target, specified as a UNC name,");
	printf(" to a local directory.\n");
	if(mountpassword) {
		memset(mountpassword,0,64);
		free(mountpassword);
	}
	exit(1);
}

/* caller frees username if necessary */
static char * getusername(void) {
	char *username = NULL;
	struct passwd *password = getpwuid(getuid());

	if (password) {
		username = password->pw_name;
	}
	return username;
}

char * parse_cifs_url(char * unc_name)
{
	printf("\ncifs url %s\n",unc_name);
	return NULL;
}

static int open_cred_file(char * file_name)
{
	char * line_buf;
	char * temp_val;
	FILE * fs;
	int i, length;
	fs = fopen(file_name,"r");
	if(fs == NULL)
		return errno;
	line_buf = malloc(4096);
	if(line_buf == NULL)
		return -ENOMEM;

	while(fgets(line_buf,4096,fs)) {
		/* parse line from credential file */

		/* eat leading white space */
		for(i=0;i<4096;i++) {
			if(line_buf[i] == '\0')
				break;
			else if((line_buf[i] != ' ') && (line_buf[i] != '\t'))
				break;
			line_buf++;
		}

		if (strncasecmp("username",line_buf,8) == 0) {
			temp_val = strchr(line_buf + i,'=');
			if(temp_val) {
				/* go past equals sign */
				temp_val++;
				length = strlen(temp_val);
				if(length > 4086) {
					printf("cifs.mount failed due to malformed username in credentials file");
					memset(line_buf,0,4096);
					if(mountpassword) {
						memset(mountpassword,0,64);
					}
					exit(1);
				} else {
					got_user = 1;
					user_name = calloc(1 + length,1);
					/* BB adding free of user_name string before exit,
						not really necessary but would be cleaner */
					strncpy(user_name,temp_val, length);
				}
			}
		} else if (strncasecmp("password",line_buf,8) == 0) {
			temp_val = strchr(line_buf+i,'=');
			if(temp_val) {
				/* go past equals sign */
				temp_val++;
				length = strlen(temp_val);
				if(length > 64) {
					printf("cifs.mount failed: password in credentials file too long\n");
					memset(line_buf,0, 4096);
					if(mountpassword) {
						memset(mountpassword,0,64);
					}
					exit(1);
				} else {
					if(mountpassword == NULL) {
						mountpassword = calloc(65,1);
					}
					if(mountpassword) {
						strncpy(mountpassword,temp_val,64);
						got_password = 1;
					}
				}
			}
		}
	}
	fclose(fs);
	if(line_buf) {
		memset(line_buf,0,4096);
		free(line_buf);
	}
	return 0;
}

static int get_password_from_file(int file_descript, char * filename)
{
	int rc = 0;
	int i;
	char c;

	if(mountpassword == NULL)
		mountpassword = calloc(65,1);
	else 
		memset(mountpassword, 0, 64);

	if(filename != NULL) {
		file_descript = open(filename, O_RDONLY);
		if(file_descript < 0) {
			printf("cifs.mount failed. %s attempting to open password file %s\n",
				   strerror(errno),filename);
			exit(1);
		}
	}
	/* else file already open and fd provided */

	for(i=0;i<64;i++) {
		rc = read(file_descript,&c,1);
		if(rc < 0) {
			printf("cifs.mount failed. Error %s reading password file\n",strerror(errno));
			memset(mountpassword,0,64);
			if(filename != NULL)
				close(file_descript);
			exit(1);
		} else if(rc == 0) {
			if(mountpassword[0] == 0) {
				if(verboseflag)
					printf("\nWarning: null password used since cifs password file empty");
			}
			break;
		} else /* read valid character */ {
			if((c == 0) || (c == '\n')) {
				break;
			} else 
				mountpassword[i] = c;
		}
	}
	if((i == 64) && (verboseflag)) {
		printf("\nWarning: password longer than 64 characters specified in cifs password file");
	}
	got_password = 1;
	if(filename != NULL) {
		close(file_descript);
	}

	return rc;
}

static int parse_options(char * options)
{
	char * data;
	char * percent_char = 0;
	char * value = 0;
	char * next_keyword = 0;
	int rc = 0;

	if (!options)
		return 1;
	else
		data = options;

	if(verboseflag)
		printf("\n parsing options: %s", options);

/* while ((data = strsep(&options, ",")) != NULL) { */
	while(data != NULL) {
		/*  check if ends with trailing comma */
		if(*data == 0)
			break;

		/* format is keyword=value,keyword2=value2,keyword3=value3 etc.) */
		/* data  = next keyword */
		/* value = next value ie stuff after equal sign */

		next_keyword = strchr(data,',');
	
		/* temporarily null terminate end of keyword=value pair */
		if(next_keyword)
			*next_keyword = 0;

		/* if (!*data)
			continue; */
		
		/* temporarily null terminate keyword to make keyword and value distinct */
		if ((value = strchr(data, '=')) != NULL) {
			*value = '\0';
			value++;
		}

		if (strncmp(data, "user", 4) == 0) {
			if (!value || !*value) {
				printf("invalid or missing username\n");
				return 1;	/* needs_arg; */
			}
			if (strnlen(value, 260) < 260) {
				got_user=1;
				percent_char = strchr(value,'%');
				if(percent_char) {
					*percent_char = ',';
					if(mountpassword == NULL)
						mountpassword = calloc(65,1);
					if(mountpassword) {
						if(got_password)
							printf("\ncifs.mount warning - password specified twice\n");
						got_password = 1;
						percent_char++;
						strncpy(mountpassword, percent_char,64);
					/*  remove password from username */
						while(*percent_char != 0) {
							*percent_char = ',';
							percent_char++;
						}
					}
				}
			} else {
				printf("username too long\n");
				return 1;
			}
		} else if (strncmp(data, "pass", 4) == 0) {
			if (!value || !*value) {
				if(got_password) {
					printf("\npassword specified twice, ignoring second\n");
				} else
					got_password = 1;
			} else if (strnlen(value, 17) < 17) {
				if(got_password)
					printf("\ncifs.mount warning - password specified twice\n");
				got_password = 1;
			} else {
				printf("password too long\n");
				return 1;
			}
		} else if (strncmp(data, "ip", 2) == 0) {
			if (!value || !*value) {
				printf("target ip address argument missing");
			} else if (strnlen(value, 35) < 35) {
				got_ip = 1;
			} else {
				printf("ip address too long\n");
				return 1;
			}
		} else if ((strncmp(data, "unc", 3) == 0)
		   || (strncmp(data, "target", 6) == 0)
		   || (strncmp(data, "path", 4) == 0)) {
			if (!value || !*value) {
				printf("invalid path to network resource\n");
				return 1;  /* needs_arg; */
			} else if(strnlen(value,5) < 5) {
				printf("UNC name too short");
			}

			if (strnlen(value, 300) < 300) {
				got_unc = 1;
				if (strncmp(value, "//", 2) == 0) {
					if(got_unc)
						printf("unc name specified twice, ignoring second\n");
					else
						got_unc = 1;
				} else if (strncmp(value, "\\\\", 2) != 0) {	                   
					printf("UNC Path does not begin with // or \\\\ \n");
					return 1;
				} else {
					if(got_unc)
						printf("unc name specified twice, ignoring second\n");
					else
						got_unc = 1;
				}
			} else {
				printf("CIFS: UNC name too long\n");
				return 1;
			}
		} else if ((strncmp(data, "domain", 3) == 0)
			   || (strncmp(data, "workgroup", 5) == 0)) {
			if (!value || !*value) {
				printf("CIFS: invalid domain name\n");
				return 1;	/* needs_arg; */
			}
			if (strnlen(value, 65) < 65) {
				got_domain = 1;
			} else {
				printf("domain name too long\n");
				return 1;
			}
		} else if (strncmp(data, "cred", 4) == 0) {
			if (value && *value) {
				rc = open_cred_file(value);
				if(rc) {
					printf("error %d opening credential file %s",rc, value);
					return 1;
				}
			} else {
				printf("invalid credential file name specified\n");
				return 1;
			}
		} else if (strncmp(data, "uid", 3) == 0) {
			if (value && *value) {
				got_uid = 1;
			}
		} else if (strncmp(data, "gid", 3) == 0) {
			if (value && *value) {
				got_gid = 1;
			}
       /* fmask and dmask synonyms for people used to smbfs syntax */
		} else if (strcmp(data, "file_mode") == 0 || strcmp(data, "fmask")==0) {
			if (!value || !*value) {
				printf ("Option '%s' requires a numerical argument\n", data);
				return 1;
			}

			if (value[0] != '0') {
				printf ("WARNING: '%s' not expressed in octal.\n", data);
			}

			if (strcmp (data, "fmask") == 0) {
				printf ("WARNING: CIFS mount option 'fmask' is deprecated. Use 'file_mode' instead.\n");
				data = "file_mode";
			}
		} else if (strcmp(data, "dir_mode") == 0 || strcmp(data, "dmask")==0) {
			if (!value || !*value) {
				printf ("Option '%s' requires a numerical argument\n", data);
				return 1;
			}

			if (value[0] != '0') {
				printf ("WARNING: '%s' not expressed in octal.\n", data);
			}

			if (strcmp (data, "dmask") == 0) {
				printf ("WARNING: CIFS mount option 'dmask' is deprecated. Use 'dir_mode' instead.\n");
				data = "dir_mode";
			}
		} /* else if (strnicmp(data, "port", 4) == 0) {
		if (value && *value) {
			vol->port =
				simple_strtoul(value, &value, 0);
		}
	} else if (strnicmp(data, "rsize", 5) == 0) {
		if (value && *value) {
			vol->rsize =
				simple_strtoul(value, &value, 0);
		}
	} else if (strnicmp(data, "wsize", 5) == 0) {
		if (value && *value) {
			vol->wsize =
				simple_strtoul(value, &value, 0);
		}
	} else if (strnicmp(data, "version", 3) == 0) {
		
	} else if (strnicmp(data, "rw", 2) == 0) {
		
	} else
		printf("CIFS: Unknown mount option %s\n",data); */

		/* move to next option */
		data = next_keyword+1;

		/* put overwritten equals sign back */
		if(value) {
			value--;
			*value = '=';
		}
		
		/* put previous overwritten comma back */
		if(next_keyword)
			*next_keyword = ',';
		else
			data = 0;

	}
	return 0;
}

/* Note that caller frees the returned buffer if necessary */
char * parse_server(char * unc_name)
{
	int length = strnlen(unc_name,1024);
	char * share;
	char * ipaddress_string = NULL;
	struct hostent * host_entry;
	struct in_addr server_ipaddr;
	int rc;

	if(length > 1023) {
		printf("mount error: UNC name too long");
		return 0;
	}
	if (strncasecmp("cifs://",unc_name,7) == 0)
		return parse_cifs_url(unc_name+7);
	if (strncasecmp("smb://",unc_name,6) == 0) {
		return parse_cifs_url(unc_name+6);
	}

	if(length < 3) {
		/* BB add code to find DFS root here */
		printf("\nMounting the DFS root for domain not implemented yet");
		return 0;
	} else {
		if(strncmp(unc_name,"//",2) && strncmp(unc_name,"\\\\",2)) {
			printf("mount error: improperly formatted UNC name.");
			printf(" %s does not begin with \\\\ or //\n",unc_name);
			return 0;
		} else {
			unc_name[0] = '\\';
			unc_name[0] = '/';
			unc_name[1] = '/';
			unc_name += 2;
			if ((share = strchr(unc_name, '/')) || 
				(share = strchr(unc_name,'\\'))) {
				*share = 0;  /* temporarily terminate the string */
				share += 1;
				host_entry = gethostbyname(unc_name);
				*(share - 1) = '/'; /* put the slash back */
/*				rc = getipnodebyname(unc_name, AF_INET, AT_ADDRCONFIG ,&rc);*/
				if(host_entry == NULL) {
					printf("mount error: could not find target server. TCP name %s not found ", unc_name);
					printf(" rc = %d\n",rc);
					return 0;
				}
				else {
					/* BB should we pass an alternate version of the share name as Unicode */
					/* BB what about ipv6? BB */
					/* BB add retries with alternate servers in list */

					memcpy(&server_ipaddr.s_addr, host_entry->h_addr, 4);

					ipaddress_string = inet_ntoa(server_ipaddr);                                                                                     
					if(ipaddress_string == NULL) {
						printf("mount error: could not get valid ip address for target server\n");
						return 0;
					}
					return ipaddress_string; 
				}
			} else {
				/* BB add code to find DFS root (send null path on get DFS Referral to specified server here */
				printf("Mounting the DFS root for a particular server not implemented yet\n");
				return 0;
			}
		}
	}
}

static struct option longopts[] = {
	{ "all", 0, 0, 'a' },
	{ "help", 0, 0, 'h' },
	{ "read-only", 0, 0, 'r' },
	{ "ro", 0, 0, 'r' },
	{ "verbose", 0, 0, 'v' },
	{ "version", 0, 0, 'V' },
	{ "read-write", 0, 0, 'w' },
	{ "rw", 0, 0, 'w' },
	{ "options", 1, 0, 'o' },
	{ "types", 1, 0, 't' },
	{ "rsize",1, 0, 'R' },
	{ "wsize",1, 0, 'W' },
	{ "uid", 1, 0, '1'},
	{ "gid", 1, 0, '2'},
	{ "uuid",1,0,'U' },
	{ "user",1,0,'u'},
	{ "username",1,0,'u'},
	{ "dom",1,0,'d'},
	{ "domain",1,0,'d'},
	{ "password",1,0,'p'},
	{ "pass",1,0,'p'},
	{ "credentials",1,0,'c'},
	{ "port",1,0,'P'},
	{ NULL, 0, 0, 0 }
};

int main(int argc, char ** argv)
{
	int c;
	int flags = MS_MANDLOCK | MS_MGC_VAL;
	char * orgoptions = NULL;
	char * share_name = NULL;
	char * domain_name = NULL;
	char * ipaddr = NULL;
	char * uuid = NULL;
	char * mountpoint;
	char * options;
	char * temp;
	int rc;
	int rsize = 0;
	int wsize = 0;
	int nomtab = 0;
	int uid = 0;
	int gid = 0;
	int optlen = 0;
	int orgoptlen = 0;
	struct stat statbuf;
	struct utsname sysinfo;
	struct mntent mountent;
	FILE * pmntfile;

	/* setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE); */

	if(argc && argv) {
		thisprogram = argv[0];
	}
	if(thisprogram == NULL)
		thisprogram = "mount.cifs";

	uname(&sysinfo);
	/* BB add workstation name and domain and pass down */

/* #ifdef _GNU_SOURCE
	printf(" node: %s machine: %s sysname %s domain %s\n", sysinfo.nodename,sysinfo.machine,sysinfo.sysname,sysinfo.domainname);
#endif */

	share_name = argv[1];
	mountpoint = argv[2];

	/* add sharename in opts string as unc= parm */

	while ((c = getopt_long (argc, argv, "afFhilL:no:O:rsU:vVwt:",
			 longopts, NULL)) != -1) {
		switch (c) {
/* No code to do the following  options yet */
/*	case 'l':
		list_with_volumelabel = 1;
		break;
	case 'L':
		volumelabel = optarg;
		break; */
/*	case 'a':	       
		++mount_all;
		break; */

		case '?':
		case 'h':	 /* help */
			mount_cifs_usage ();
			exit(1);
		case 'n':
		    ++nomtab;
		    break;
		case 'o':
			orgoptions = strdup(optarg);
		    break;
		case 'r':  /* mount readonly */
			flags |= MS_RDONLY;
			break;
		case 'U':
			uuid = optarg;
			break;
		case 'v':
			++verboseflag;
			break;
		case 'V':	   
			printf ("mount.cifs version: %s.%s%s\n",
			MOUNT_CIFS_VERSION_MAJOR,
			MOUNT_CIFS_VERSION_MINOR,
			MOUNT_CIFS_VENDOR_SUFFIX);
			if(mountpassword) {
				memset(mountpassword,0,64);
			}
			exit (0);
		case 'w':
			flags &= ~MS_RDONLY;
			break;
		case 'R':
			rsize = atoi(optarg) ;
			break;
		case 'W':
			wsize = atoi(optarg);
			break;
		case '1':
			uid = atoi(optarg);
			break;
		case '2':
			gid = atoi(optarg);
			break;
		case 'u':
			got_user = 1;
			user_name = optarg;
			break;
		case 'd':
			domain_name = optarg;
			break;
		case 'p':
			if(mountpassword == NULL)
				mountpassword = calloc(65,1);
			if(mountpassword) {
				got_password = 1;
				strncpy(mountpassword,optarg,64);
			}
			break;
		case 't':
			break;
		default:
			printf("unknown mount option %c\n",c);
			mount_cifs_usage();
			exit(1);
		}
	}

	if(argc < 3)
		mount_cifs_usage();

	if (getenv("PASSWD")) {
		if(mountpassword == NULL)
			mountpassword = calloc(65,1);
		if(mountpassword) {
			strncpy(mountpassword,getenv("PASSWD"),64);
			got_password = 1;
		}
	} else if (getenv("PASSWD_FD")) {
		get_password_from_file(atoi(getenv("PASSWD_FD")),NULL);
	} else if (getenv("PASSWD_FILE")) {
		get_password_from_file(0, getenv("PASSWD_FILE"));
	}

	ipaddr = parse_server(share_name);
	
	if (orgoptions && parse_options(orgoptions))
		return 1;

	/* BB save off path and pop after mount returns? */
	/* BB canonicalize the path in argv[1]? */

	if(chdir(mountpoint)) {
		printf("mount error: can not change directory into mount target %s\n",mountpoint);
	}

	if(stat (mountpoint, &statbuf)) {
		printf("mount error: mount point %s does not exist\n",mountpoint);
		return -1;
	}

	if (S_ISDIR(statbuf.st_mode) == 0) {
		printf("mount error: mount point %s is not a directory\n",mountpoint);
		return -1;
	}

	if((getuid() != 0) && (geteuid() == 0)) {
		if((statbuf.st_uid == getuid()) && (S_IRWXU == (statbuf.st_mode & S_IRWXU))) {
			printf("setuid mount allowed\n");
		} else {
			printf("mount error: permission denied or not superuser and cifs.mount not installed SUID\n"); 
			return -1;
		}
	}

	if(got_user == 0)
		user_name = getusername();
       
	if(got_password == 0) {
		mountpassword = getpass("Password: "); /* BB obsolete */
		got_password = 1;
	}
	/* FIXME launch daemon (handles dfs name resolution and credential change) 
	   remember to clear parms and overwrite password field before launching */
	if(orgoptions) {
		optlen = strlen(orgoptions);
		orgoptlen = optlen;
	} else
		optlen = 0;
	if(share_name)
		optlen += strlen(share_name) + 4;
	if(user_name)
		optlen += strlen(user_name) + 6;
	if(ipaddr)
		optlen += strlen(ipaddr) + 4;
	if(mountpassword)
		optlen += strlen(mountpassword) + 6;
	options = malloc(optlen + 10);

	options[0] = 0;
	strncat(options,"unc=",4);
	strcat(options,share_name);
	/* scan backwards and reverse direction of slash */
	temp = strrchr(options, '/');
	if(temp > options + 6)
		*temp = '\\';
	if(ipaddr) {
		strncat(options,",ip=",4);
		strcat(options,ipaddr);
	} 
	if(user_name) {
		strncat(options,",user=",6);
		strcat(options,user_name);
	} 
	if(mountpassword) {
		strncat(options,",pass=",6);
		strcat(options,mountpassword);
	}
	strncat(options,",ver=",5);
	strcat(options,MOUNT_CIFS_VERSION_MAJOR);

	if(orgoptions) {
		strcat(options,",");
		strcat(options,orgoptions);
	}
	if(verboseflag)
		printf("\ncifs.mount kernel mount options %s \n",options);
	if(mount(share_name, mountpoint, "cifs", flags, options)) {
	/* remember to kill daemon on error */
		switch (errno) {
		case 0:
			printf("mount failed but no error number set\n");
			break;
		case ENODEV:
			printf("mount error: cifs filesystem not supported by the system\n");
			break;
		default:
			printf("mount error %d = %s\n",errno,strerror(errno));
		}
		printf("Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)\n");
		if(mountpassword) {
			memset(mountpassword,0,64);
		}
		return -1;
	} else {
		pmntfile = setmntent(MOUNTED, "a+");
		if(pmntfile) {
			mountent.mnt_fsname = share_name;
			mountent.mnt_dir = mountpoint; 
			mountent.mnt_type = "cifs"; 
			mountent.mnt_opts = "";
			mountent.mnt_freq = 0;
			mountent.mnt_passno = 0;
			rc = addmntent(pmntfile,&mountent);
			endmntent(pmntfile);
		} else {
		    printf("could not update mount table\n");
		}
	}
	if(mountpassword) {
		memset(mountpassword,0,64);
		free(mountpassword);
	}

	if(options) {
		memset(options,0,optlen);
		free(options);
	}

	if(orgoptions) {
		memset(orgoptions,0,orgoptlen);
		free(orgoptions);
	}
	return 0;
}