[apt.git] / apt-pkg / contrib / cdromutl.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: cdromutl.cc,v 1.12 2001/02/20 07:03:17 jgg Exp $
/* ######################################################################
   
   CDROM Utilities - Some functions to manipulate CDROM mounts.
   
   These are here for the cdrom method and apt-cdrom.
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#include<config.h>

#include <apt-pkg/cdromutl.h>
#include <apt-pkg/error.h>
#include <apt-pkg/md5.h>
#include <apt-pkg/fileutl.h>
#include <apt-pkg/configuration.h>
#include <apt-pkg/strutl.h>

#include <stdlib.h>
#include <string.h>
#include <iostream>
#include <string>
#include <vector>
#include <sys/statvfs.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>

#include <apti18n.h>
									/*}}}*/

using std::string;

// IsMounted - Returns true if the mount point is mounted		/*{{{*/
// ---------------------------------------------------------------------
/* This is a simple algorithm that should always work, we stat the mount point
   and the '..' file in the mount point and see if they are on the same device.
   By definition if they are the same then it is not mounted. This should 
   account for symlinked mount points as well. */
bool IsMounted(string &Path)
{
   if (Path.empty() == true)
      return false;

   // Need that trailing slash for directories
   if (Path[Path.length() - 1] != '/')
      Path += '/';

   // if the path has a ".disk" directory we treat it as mounted
   // this way even extracted copies of disks are recognized
   if (DirectoryExists(Path + ".disk/") == true)
      return true;

   /* First we check if the path is actually mounted, we do this by
      stating the path and the previous directory (careful of links!)
      and comparing their device fields. */
   struct stat Buf,Buf2;
   if (stat(Path.c_str(),&Buf) != 0 || 
       stat((Path + "../").c_str(),&Buf2) != 0)
      return _error->Errno("stat",_("Unable to stat the mount point %s"),Path.c_str());

   if (Buf.st_dev == Buf2.st_dev)
      return false;
   return true;
}
									/*}}}*/
// UnmountCdrom - Unmount a cdrom					/*{{{*/
// ---------------------------------------------------------------------
/* Forking umount works much better than the umount syscall which can 
   leave /etc/mtab inconsitant. We drop all messages this produces. */
bool UnmountCdrom(string Path)
{
   // do not generate errors, even if the mountpoint does not exist
   // the mountpoint might be auto-created by the mount command
   // and a non-existing mountpoint is surely not mounted
   _error->PushToStack();
   bool const mounted = IsMounted(Path);
   _error->RevertToStack();
   if (mounted == false)
      return true;

   for (int i=0;i<3;i++)
   {
   
      int Child = ExecFork();

      // The child
      if (Child == 0)
      {
	 // Make all the fds /dev/null
	 int const null_fd = open("/dev/null",O_RDWR);
	 for (int I = 0; I != 3; ++I)
	    dup2(null_fd, I);

	 if (_config->Exists("Acquire::cdrom::"+Path+"::UMount") == true)
	 {
	    if (system(_config->Find("Acquire::cdrom::"+Path+"::UMount").c_str()) != 0)
	       _exit(100);
	    _exit(0);	 	 
	 }
	 else
	 {
	    const char *Args[10];
	    Args[0] = "umount";
	    Args[1] = Path.c_str();
	    Args[2] = 0;
	    execvp(Args[0],(char **)Args);      
	    _exit(100);
	 }      
      }

      // if it can not be umounted, give it a bit more time
      // this can happen when auto-mount magic or fs/cdrom prober attack
      if (ExecWait(Child,"umount",true) == true)
	 return true;
      sleep(1);
   }

   return false;
}
									/*}}}*/
// MountCdrom - Mount a cdrom						/*{{{*/
// ---------------------------------------------------------------------
/* We fork mount and drop all messages */
bool MountCdrom(string Path, string DeviceName)
{
   // do not generate errors, even if the mountpoint does not exist
   // the mountpoint might be auto-created by the mount command
   _error->PushToStack();
   bool const mounted = IsMounted(Path);
   _error->RevertToStack();
   if (mounted == true)
      return true;

   int Child = ExecFork();

   // The child
   if (Child == 0)
   {
      // Make all the fds /dev/null
      int const null_fd = open("/dev/null",O_RDWR);
      for (int I = 0; I != 3; ++I)
	 dup2(null_fd, I);

      if (_config->Exists("Acquire::cdrom::"+Path+"::Mount") == true)
      {
	 if (system(_config->Find("Acquire::cdrom::"+Path+"::Mount").c_str()) != 0)
	    _exit(100);
	 _exit(0);	 
      }
      else
      {
	 const char *Args[10];
	 Args[0] = "mount";
	 if (DeviceName == "") 
	 {
	    Args[1] = Path.c_str();
	    Args[2] = 0;
	 } else {
	    Args[1] = DeviceName.c_str();
	    Args[2] = Path.c_str();
	    Args[3] = 0;
	 }
	 execvp(Args[0],(char **)Args);      
	 _exit(100);
      }      
   }

   // Wait for mount
   return ExecWait(Child,"mount",true);
}
									/*}}}*/
// IdentCdrom - Generate a unique string for this CD			/*{{{*/
// ---------------------------------------------------------------------
/* We convert everything we hash into a string, this prevents byte size/order
   from effecting the outcome. */
bool IdentCdrom(string CD,string &Res,unsigned int Version)
{
   MD5Summation Hash;
   bool writable_media = false;

   // if we are on a writable medium (like a usb-stick) that is just
   // used like a cdrom don't use "." as it will constantly change,
   // use .disk instead
   if (access(CD.c_str(), W_OK) == 0 && DirectoryExists(CD+string("/.disk"))) 
   {
      writable_media = true;
      CD = CD.append("/.disk");
      if (_config->FindB("Debug::aptcdrom",false) == true)
         std::clog << "Found writable cdrom, using alternative path: " << CD
                   << std::endl;
   }

   string StartDir = SafeGetCWD();
   if (chdir(CD.c_str()) != 0)
      return _error->Errno("chdir",_("Unable to change to %s"),CD.c_str());
   
   DIR *D = opendir(".");
   if (D == 0)
      return _error->Errno("opendir",_("Unable to read %s"),CD.c_str());
      
   /* Run over the directory, we assume that the reader order will never
      change as the media is read-only. In theory if the kernel did
      some sort of wacked caching this might not be true.. */
   for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
   {
      // Skip some files..
      if (strcmp(Dir->d_name,".") == 0 ||
	  strcmp(Dir->d_name,"..") == 0)
	 continue;

      std::string S;
      if (Version <= 1)
      {
	 strprintf(S, "%lu", (unsigned long)Dir->d_ino);
      }
      else
      {
	 struct stat Buf;
	 if (stat(Dir->d_name,&Buf) != 0)
	    continue;
	 strprintf(S, "%lu", (unsigned long)Buf.st_mtime);
      }

      Hash.Add(S.c_str());
      Hash.Add(Dir->d_name);
   };

   if (chdir(StartDir.c_str()) != 0) {
      _error->Errno("chdir",_("Unable to change to %s"),StartDir.c_str());
      closedir(D);
      return false;
   }
   closedir(D);

   // Some stats from the fsys
   std::string S;
   if (_config->FindB("Debug::identcdrom",false) == false)
   {
      struct statvfs Buf;
      if (statvfs(CD.c_str(),&Buf) != 0)
	 return _error->Errno("statfs",_("Failed to stat the cdrom"));

      // We use a kilobyte block size to advoid overflow
      if (writable_media)
      {
         strprintf(S, "%lu", (unsigned long)(Buf.f_blocks*(Buf.f_bsize/1024)));
      } else {
         strprintf(S, "%lu %lu", (unsigned long)(Buf.f_blocks*(Buf.f_bsize/1024)),
                 (unsigned long)(Buf.f_bfree*(Buf.f_bsize/1024)));
      }
      Hash.Add(S.c_str());
      strprintf(S, "-%u", Version);
   }
   else
      strprintf(S, "-%u.debug", Version);

   Res = Hash.Result().Value() + S;
   return true;
}
									/*}}}*/
// FindMountPointForDevice - Find mountpoint for the given device	/*{{{*/
string FindMountPointForDevice(const char *devnode)
{
   // this is the order that mount uses as well
   std::vector<std::string> const mounts = _config->FindVector("Dir::state::MountPoints", "/etc/mtab,/proc/mount");

   for (std::vector<std::string>::const_iterator m = mounts.begin(); m != mounts.end(); ++m)
      if (FileExists(*m) == true)
      {
	 char * line = NULL;
	 size_t line_len = 0;
	 FILE * f = fopen(m->c_str(), "r");
	 while(getline(&line, &line_len, f) != -1)
	 {
	    char * out[] = { NULL, NULL, NULL };
	    TokSplitString(' ', line, out, 3);
	    if (out[2] != NULL || out[1] == NULL || out[0] == NULL)
	       continue;
	    if (strcmp(out[0], devnode) != 0)
	       continue;
	    fclose(f);
	    // unescape the \0XXX chars in the path
	    string mount_point = out[1];
	    free(line);
	    return DeEscapeString(mount_point);
	 }
	 fclose(f);
	 free(line);
      }

   return string();
}
									/*}}}*/
Commit	Line	Data
d669751b AL	1	// -- mode: cpp; mode: fold --
d669751b AL	2	// Description /{{{/
b2e465d6	3	// $Id: cdromutl.cc,v 1.12 2001/02/20 07:03:17 jgg Exp $
d669751b AL	4	/* ######################################################################
	5
	6	CDROM Utilities - Some functions to manipulate CDROM mounts.
	7
	8	These are here for the cdrom method and apt-cdrom.
	9
	10	##################################################################### */
	11	/}}}/
	12	// Include Files /{{{/
ea542140 DK	13	#include<config.h>
ea542140 DK	14
d669751b AL	15	#include <apt-pkg/cdromutl.h>
	16	#include <apt-pkg/error.h>
	17	#include <apt-pkg/md5.h>
	18	#include <apt-pkg/fileutl.h>
6c907975	19	#include <apt-pkg/configuration.h>
ef381816	20	#include <apt-pkg/strutl.h>
d669751b	21
453b82a3 DK	22	#include <stdlib.h>
	23	#include <string.h>
	24	#include <iostream>
	25	#include <string>
12844170	26	#include <vector>
101030ab	27	#include <sys/statvfs.h>
d669751b AL	28	#include <dirent.h>
d669751b AL	29	#include <fcntl.h>
4df0b629	30	#include <sys/stat.h>
d669751b AL	31	#include <unistd.h>
d669751b AL	32	#include <stdio.h>
ea542140 DK	33
ea542140 DK	34	#include <apti18n.h>
d669751b AL	35	/}}}/
d669751b AL	36
8f3ba4e8 DK	37	using std::string;
8f3ba4e8 DK	38
6c907975	39	// IsMounted - Returns true if the mount point is mounted /{{{/
d669751b	40	// ---------------------------------------------------------------------
6c907975 AL	41	/* This is a simple algorithm that should always work, we stat the mount point
	42	and the '..' file in the mount point and see if they are on the same device.
	43	By definition if they are the same then it is not mounted. This should
	44	account for symlinked mount points as well. */
	45	bool IsMounted(string &Path)
d669751b	46	{
4df0b629 AL	47	if (Path.empty() == true)
4df0b629 AL	48	return false;
79bde56e	49
4df0b629 AL	50	// Need that trailing slash for directories
	51	if (Path[Path.length() - 1] != '/')
	52	Path += '/';
79bde56e DK	53
	54	// if the path has a ".disk" directory we treat it as mounted
	55	// this way even extracted copies of disks are recognized
	56	if (DirectoryExists(Path + ".disk/") == true)
	57	return true;
	58
1e3f4083 MV	59	/* First we check if the path is actually mounted, we do this by
1e3f4083 MV	60	stating the path and the previous directory (careful of links!)
4df0b629 AL	61	and comparing their device fields. */
	62	struct stat Buf,Buf2;
	63	if (stat(Path.c_str(),&Buf) != 0 \|\|
	64	stat((Path + "../").c_str(),&Buf2) != 0)
b2e465d6	65	return _error->Errno("stat",_("Unable to stat the mount point %s"),Path.c_str());
4df0b629 AL	66
4df0b629 AL	67	if (Buf.st_dev == Buf2.st_dev)
6c907975 AL	68	return false;
	69	return true;
	70	}
	71	/}}}/
	72	// UnmountCdrom - Unmount a cdrom /{{{/
	73	// ---------------------------------------------------------------------
	74	/* Forking umount works much better than the umount syscall which can
	75	leave /etc/mtab inconsitant. We drop all messages this produces. */
	76	bool UnmountCdrom(string Path)
	77	{
454b97a5 DK	78	// do not generate errors, even if the mountpoint does not exist
	79	// the mountpoint might be auto-created by the mount command
	80	// and a non-existing mountpoint is surely not mounted
	81	_error->PushToStack();
	82	bool const mounted = IsMounted(Path);
	83	_error->RevertToStack();
	84	if (mounted == false)
4df0b629	85	return true;
d669751b	86
5ae004ce	87	for (int i=0;i<3;i++)
d669751b	88	{
5ae004ce MV	89
5ae004ce MV	90	int Child = ExecFork();
d669751b	91
5ae004ce MV	92	// The child
5ae004ce MV	93	if (Child == 0)
6c907975	94	{
5ae004ce	95	// Make all the fds /dev/null
454b97a5 DK	96	int const null_fd = open("/dev/null",O_RDWR);
	97	for (int I = 0; I != 3; ++I)
	98	dup2(null_fd, I);
5ae004ce MV	99
	100	if (_config->Exists("Acquire::cdrom::"+Path+"::UMount") == true)
	101	{
	102	if (system(_config->Find("Acquire::cdrom::"+Path+"::UMount").c_str()) != 0)
	103	_exit(100);
	104	_exit(0);
	105	}
	106	else
	107	{
	108	const char *Args[10];
	109	Args[0] = "umount";
	110	Args[1] = Path.c_str();
	111	Args[2] = 0;
	112	execvp(Args[0],(char **)Args);
6c907975	113	_exit(100);
5ae004ce	114	}
6c907975	115	}
5ae004ce MV	116
	117	// if it can not be umounted, give it a bit more time
	118	// this can happen when auto-mount magic or fs/cdrom prober attack
	119	if (ExecWait(Child,"umount",true) == true)
	120	return true;
	121	sleep(1);
d669751b AL	122	}
d669751b AL	123
5ae004ce	124	return false;
d669751b AL	125	}
	126	/}}}/
	127	// MountCdrom - Mount a cdrom /{{{/
	128	// ---------------------------------------------------------------------
	129	/* We fork mount and drop all messages */
a6418a4b	130	bool MountCdrom(string Path, string DeviceName)
d669751b	131	{
454b97a5 DK	132	// do not generate errors, even if the mountpoint does not exist
	133	// the mountpoint might be auto-created by the mount command
	134	_error->PushToStack();
	135	bool const mounted = IsMounted(Path);
	136	_error->RevertToStack();
	137	if (mounted == true)
6c907975	138	return true;
454b97a5	139
54676e1a	140	int Child = ExecFork();
d669751b AL	141
	142	// The child
	143	if (Child == 0)
	144	{
	145	// Make all the fds /dev/null
454b97a5 DK	146	int const null_fd = open("/dev/null",O_RDWR);
454b97a5 DK	147	for (int I = 0; I != 3; ++I)
fe0036dd	148	dup2(null_fd, I);
454b97a5	149
6c907975 AL	150	if (_config->Exists("Acquire::cdrom::"+Path+"::Mount") == true)
	151	{
	152	if (system(_config->Find("Acquire::cdrom::"+Path+"::Mount").c_str()) != 0)
	153	_exit(100);
	154	_exit(0);
	155	}
	156	else
	157	{
	158	const char *Args[10];
	159	Args[0] = "mount";
a6418a4b MV	160	if (DeviceName == "")
	161	{
	162	Args[1] = Path.c_str();
	163	Args[2] = 0;
	164	} else {
	165	Args[1] = DeviceName.c_str();
	166	Args[2] = Path.c_str();
	167	Args[3] = 0;
	168	}
6c907975 AL	169	execvp(Args[0],(char **)Args);
	170	_exit(100);
	171	}
d669751b AL	172	}
	173
	174	// Wait for mount
ddc1d8d0	175	return ExecWait(Child,"mount",true);
d669751b AL	176	}
	177	/}}}/
	178	// IdentCdrom - Generate a unique string for this CD /{{{/
	179	// ---------------------------------------------------------------------
	180	/* We convert everything we hash into a string, this prevents byte size/order
	181	from effecting the outcome. */
34fc0421	182	bool IdentCdrom(string CD,string &Res,unsigned int Version)
d669751b AL	183	{
d669751b AL	184	MD5Summation Hash;
4dc7b4a7	185	bool writable_media = false;
d669751b	186
2a001232 MV	187	// if we are on a writable medium (like a usb-stick) that is just
	188	// used like a cdrom don't use "." as it will constantly change,
	189	// use .disk instead
4dc7b4a7 MV	190	if (access(CD.c_str(), W_OK) == 0 && DirectoryExists(CD+string("/.disk")))
	191	{
	192	writable_media = true;
7970157f	193	CD = CD.append("/.disk");
2a001232	194	if (_config->FindB("Debug::aptcdrom",false) == true)
7970157f MV	195	std::clog << "Found writable cdrom, using alternative path: " << CD
7970157f MV	196	<< std::endl;
2a001232 MV	197	}
2a001232 MV	198
d669751b AL	199	string StartDir = SafeGetCWD();
d669751b AL	200	if (chdir(CD.c_str()) != 0)
b2e465d6	201	return _error->Errno("chdir",_("Unable to change to %s"),CD.c_str());
d669751b AL	202
	203	DIR *D = opendir(".");
	204	if (D == 0)
b2e465d6	205	return _error->Errno("opendir",_("Unable to read %s"),CD.c_str());
d669751b	206
4df0b629 AL	207	/* Run over the directory, we assume that the reader order will never
	208	change as the media is read-only. In theory if the kernel did
	209	some sort of wacked caching this might not be true.. */
d669751b AL	210	for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
	211	{
	212	// Skip some files..
	213	if (strcmp(Dir->d_name,".") == 0 \|\|
	214	strcmp(Dir->d_name,"..") == 0)
	215	continue;
34fc0421	216
b8eba208	217	std::string S;
34fc0421 AL	218	if (Version <= 1)
34fc0421 AL	219	{
b8eba208	220	strprintf(S, "%lu", (unsigned long)Dir->d_ino);
34fc0421 AL	221	}
	222	else
	223	{
	224	struct stat Buf;
	225	if (stat(Dir->d_name,&Buf) != 0)
	226	continue;
b8eba208	227	strprintf(S, "%lu", (unsigned long)Buf.st_mtime);
34fc0421	228	}
b8eba208 DK	229
b8eba208 DK	230	Hash.Add(S.c_str());
d669751b AL	231	Hash.Add(Dir->d_name);
d669751b AL	232	};
b8eba208	233
6070a346 DK	234	if (chdir(StartDir.c_str()) != 0) {
	235	_error->Errno("chdir",_("Unable to change to %s"),StartDir.c_str());
	236	closedir(D);
	237	return false;
	238	}
d669751b	239	closedir(D);
b8eba208	240
d669751b	241	// Some stats from the fsys
b8eba208	242	std::string S;
fbdccabb AL	243	if (_config->FindB("Debug::identcdrom",false) == false)
fbdccabb AL	244	{
101030ab AL	245	struct statvfs Buf;
101030ab AL	246	if (statvfs(CD.c_str(),&Buf) != 0)
b2e465d6	247	return _error->Errno("statfs",_("Failed to stat the cdrom"));
4dc7b4a7	248
fbdccabb	249	// We use a kilobyte block size to advoid overflow
4dc7b4a7 MV	250	if (writable_media)
4dc7b4a7 MV	251	{
b8eba208	252	strprintf(S, "%lu", (unsigned long)(Buf.f_blocks*(Buf.f_bsize/1024)));
4dc7b4a7	253	} else {
b8eba208 DK	254	strprintf(S, "%lu %lu", (unsigned long)(Buf.f_blocks*(Buf.f_bsize/1024)),
b8eba208 DK	255	(unsigned long)(Buf.f_bfree*(Buf.f_bsize/1024)));
4dc7b4a7	256	}
b8eba208 DK	257	Hash.Add(S.c_str());
b8eba208 DK	258	strprintf(S, "-%u", Version);
fbdccabb AL	259	}
fbdccabb AL	260	else
b8eba208 DK	261	strprintf(S, "-%u.debug", Version);
b8eba208 DK	262
34fc0421	263	Res = Hash.Result().Value() + S;
b8eba208	264	return true;
d669751b AL	265	}
d669751b AL	266	/}}}/
6070a346	267	// FindMountPointForDevice - Find mountpoint for the given device /{{{/
02aa6f67	268	string FindMountPointForDevice(const char *devnode)
ef381816	269	{
ef381816	270	// this is the order that mount uses as well
12844170	271	std::vector<std::string> const mounts = _config->FindVector("Dir::state::MountPoints", "/etc/mtab,/proc/mount");
ef381816	272
12844170 DK	273	for (std::vector<std::string>::const_iterator m = mounts.begin(); m != mounts.end(); ++m)
	274	if (FileExists(*m) == true)
	275	{
	276	char * line = NULL;
	277	size_t line_len = 0;
	278	FILE * f = fopen(m->c_str(), "r");
	279	while(getline(&line, &line_len, f) != -1)
	280	{
	281	char * out[] = { NULL, NULL, NULL };
	282	TokSplitString(' ', line, out, 3);
	283	if (out[2] != NULL \|\| out[1] == NULL \|\| out[0] == NULL)
	284	continue;
	285	if (strcmp(out[0], devnode) != 0)
	286	continue;
	287	fclose(f);
	288	// unescape the \0XXX chars in the path
	289	string mount_point = out[1];
3d8232bf	290	free(line);
12844170 DK	291	return DeEscapeString(mount_point);
	292	}
	293	fclose(f);
3d8232bf	294	free(line);
ef381816	295	}
12844170	296
02aa6f67	297	return string();
ef381816	298	}
6070a346	299	/}}}/