mount.cifs.c

samba-3.0.22.tar.gz 编译smb服务器的源码

/* 
   Mount helper utility for Linux CIFS VFS (virtual filesystem) client
   Copyright (C) 2003,2005 Steve French  ([e-mail])

   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 <grp.h>
#include <ctype.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 "10"

#ifndef MOUNT_CIFS_VENDOR_SUFFIX
#define MOUNT_CIFS_VENDOR_SUFFIX ""
#endif

#ifndef MS_MOVE 
#define MS_MOVE 8192 
#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 int free_share_name = 0;
static char * user_name = NULL;
static char * mountpassword = NULL;
char * domain_name = 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 char * check_for_domain(char **);


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\nOptions:\n");
	printf("\tuser=<arg>\n\tpass=<arg>\n\tdom=<arg>\n");
	printf("\nLess commonly used options:");
	printf("\n\tcredentials=<filename>,guest,perm,noperm,setuids,nosetuids,rw,ro,");
	printf("\n\tsep=<char>,iocharset=<codepage>,suid,nosuid,exec,noexec,serverino,");
	printf("\n\tdirectio,mapchars,nomapchars,nolock,servernetbiosname=<SRV_RFC1001NAME>");
	printf("\n\nOptions not needed for servers supporting CIFS Unix extensions");
	printf("\n\t(e.g. unneeded for mounts to most Samba versions):");
	printf("\n\tuid=<uid>,gid=<gid>,dir_mode=<mode>,file_mode=<mode>,sfu");
	printf("\n\nRarely used options:");
	printf("\n\tport=<tcpport>,rsize=<size>,wsize=<size>,unc=<unc_name>,ip=<ip_address>,");
	printf("\n\tdev,nodev,nouser_xattr,netbiosname=<OUR_RFC1001NAME>,hard,soft,intr,");
	printf("\n\tnointr,ignorecase,noposixpaths,noacl");
	printf("\n\nOptions are described in more detail in the manual page");
	printf("\n\tman 8 mount.cifs\n");
	printf("\nTo display the version number of the mount helper:");
	printf("\n\t%s -V\n",thisprogram);

	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;
}

static char * parse_cifs_url(char * unc_name)
{
	printf("\nMounting cifs URL not implemented yet. Attempt to mount %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) {
		fclose(fs);
		return -ENOMEM;
	}

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

		/* eat leading white space */
		for(i=0;i<4086;i++) {
			if((line_buf[i] != ' ') && (line_buf[i] != '\t'))
				break;
			/* if whitespace - skip past it */
		}
		if (strncasecmp("username",line_buf+i,8) == 0) {
			temp_val = strchr(line_buf + i,'=');
			if(temp_val) {
				/* go past equals sign */
				temp_val++;
				for(length = 0;length<4087;length++) {
					if(temp_val[length] == '\n')
						break;
				}
				if(length > 4086) {
					printf("mount.cifs 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+i,8) == 0) {
			temp_val = strchr(line_buf+i,'=');
			if(temp_val) {
				/* go past equals sign */
				temp_val++;
				for(length = 0;length<65;length++) {
					if(temp_val[length] == '\n')
						break;
				}
				if(length > 64) {
					printf("mount.cifs 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);
					} else
						memset(mountpassword,0,64);
					if(mountpassword) {
						strncpy(mountpassword,temp_val,length);
						got_password = 1;
					}
				}
			}
                } else if (strncasecmp("domain",line_buf+i,6) == 0) {
                        temp_val = strchr(line_buf+i,'=');
                        if(temp_val) {
                                /* go past equals sign */
                                temp_val++;
				if(verboseflag)
					printf("\nDomain %s\n",temp_val);
                                for(length = 0;length<65;length++) {
                                        if(temp_val[length] == '\n')
                                                break;
                                }
                                if(length > 64) {
                                        printf("mount.cifs failed: domain in credentials file too long\n");
                                        if(mountpassword) {
                                                memset(mountpassword,0,64);
                                        }
                                        exit(1);
                                } else {
                                        if(domain_name == NULL) {
                                                domain_name = calloc(65,1);
                                        } else
                                                memset(domain_name,0,64);
                                        if(domain_name) {
                                                strncpy(domain_name,temp_val,length);
                                                got_domain = 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("mount.cifs 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("mount.cifs 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 ** optionsp, int * filesys_flags)
{
	char * data;
	char * percent_char = NULL;
	char * value = NULL;
	char * next_keyword = NULL;
	char * out = NULL;
	int out_len = 0;
	int word_len;
	int rc = 0;

	if (!optionsp || !*optionsp)
		return 1;
	data = *optionsp;

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

	/* BB fixme check for separator override BB */

/* 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,','); /* BB handle sep= */
	
		/* temporarily null terminate end of keyword=value pair */
		if(next_keyword)
			*next_keyword++ = 0;

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

		if (strncmp(data, "users",5) == 0) {
			if(!value || !*value) {
				goto nocopy;
			}
		} else if (strncmp(data, "user_xattr",10) == 0) {
		   /* do nothing - need to skip so not parsed as user name */
		} else if (strncmp(data, "user", 4) == 0) {

			if (!value || !*value) {
				if(data[4] == '\0') {
					if(verboseflag)
						printf("\nskipping empty user mount parameter\n");
					/* remove the parm since it would otherwise be confusing
					to the kernel code which would think it was a real username */
					goto nocopy;
				} else {
					printf("username specified with no parameter\n");
					return 1;	/* needs_arg; */
				}
			} else {
				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("\nmount.cifs 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++;
							}
						}
					}
					/* this is only case in which the user
					name buf is not malloc - so we have to
					check for domain name embedded within
					the user name here since the later
					call to check_for_domain will not be
					invoked */
					domain_name = check_for_domain(&value);
				} 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("\nmount.cifs 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) {
				if(verboseflag)
					printf("ip address %s override specified\n",value);
				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");
			}