glibc/nss/makedb.c

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/* Create simple DB database from textual input.
Copyright (C) 1996-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <argp.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libintl.h>
#include <locale.h>
#include <search.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
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#include <sys/param.h>
#include <sys/stat.h>
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#include <sys/uio.h>
#include "nss_db/nss_db.h"
/* Get libc version number. */
#include "../version.h"
/* The hashing function we use. */
#include "../intl/hash-string.h"
/* SELinux support. */
#ifdef HAVE_SELINUX
# include <selinux/selinux.h>
#endif
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#ifndef MAP_POPULATE
# define MAP_POPULATE 0
#endif
#define PACKAGE _libc_intl_domainname
/* List of data bases. */
struct database
{
char dbid;
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bool extra_string;
struct database *next;
void *entries;
size_t nentries;
size_t nhashentries;
stridx_t *hashtable;
size_t keystrlen;
stridx_t *keyidxtab;
char *keystrtab;
} *databases;
static size_t ndatabases;
static size_t nhashentries_total;
static size_t valstrlen;
static void *valstrtree;
static char *valstrtab;
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static size_t extrastrlen;
/* Database entry. */
struct dbentry
{
stridx_t validx;
uint32_t hashval;
char str[0];
};
/* Stored string entry. */
struct valstrentry
{
stridx_t idx;
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bool extra_string;
char str[0];
};
/* True if any entry has been added. */
static bool any_dbentry;
/* If non-zero convert key to lower case. */
static int to_lowercase;
/* If non-zero print content of input file, one entry per line. */
static int do_undo;
/* If non-zero do not print informational messages. */
static int be_quiet;
/* Name of output file. */
static const char *output_name;
/* Name and version of program. */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
/* Definitions of arguments for argp functions. */
static const struct argp_option options[] =
{
{ "fold-case", 'f', NULL, 0, N_("Convert key to lower case") },
{ "output", 'o', N_("NAME"), 0, N_("Write output to file NAME") },
{ "quiet", 'q', NULL, 0,
N_("Do not print messages while building database") },
{ "undo", 'u', NULL, 0,
N_("Print content of database file, one entry a line") },
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{ "generated", 'g', N_("CHAR"), 0,
N_("Generated line not part of iteration") },
{ NULL, 0, NULL, 0, NULL }
};
/* Short description of program. */
static const char doc[] = N_("Create simple database from textual input.");
/* Strings for arguments in help texts. */
static const char args_doc[] = N_("\
INPUT-FILE OUTPUT-FILE\n-o OUTPUT-FILE INPUT-FILE\n-u INPUT-FILE");
/* Prototype for option handler. */
static error_t parse_opt (int key, char *arg, struct argp_state *state);
/* Function to print some extra text in the help message. */
static char *more_help (int key, const char *text, void *input);
/* Data structure to communicate with argp functions. */
static struct argp argp =
{
options, parse_opt, args_doc, doc, NULL, more_help
};
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/* List of databases which are not part of the iteration table. */
static struct db_option
{
char dbid;
struct db_option *next;
} *db_options;
/* Prototypes for local functions. */
static int process_input (FILE *input, const char *inname,
int to_lowercase, int be_quiet);
static int print_database (int fd);
static void compute_tables (void);
static int write_output (int fd);
/* SELinux support. */
#ifdef HAVE_SELINUX
/* Set the SELinux file creation context for the given file. */
static void set_file_creation_context (const char *outname, mode_t mode);
static void reset_file_creation_context (void);
#else
# define set_file_creation_context(_outname,_mode)
# define reset_file_creation_context()
#endif
/* External functions. */
#include <programs/xmalloc.h>
int
main (int argc, char *argv[])
{
const char *input_name;
FILE *input_file;
int remaining;
int mode = 0644;
/* Set locale via LC_ALL. */
setlocale (LC_ALL, "");
/* Set the text message domain. */
textdomain (_libc_intl_domainname);
/* Initialize local variables. */
input_name = NULL;
/* Parse and process arguments. */
argp_parse (&argp, argc, argv, 0, &remaining, NULL);
/* Determine file names. */
if (do_undo || output_name != NULL)
{
if (remaining + 1 != argc)
{
wrong_arguments:
error (0, 0, gettext ("wrong number of arguments"));
argp_help (&argp, stdout, ARGP_HELP_SEE,
program_invocation_short_name);
exit (1);
}
input_name = argv[remaining];
}
else
{
if (remaining + 2 != argc)
goto wrong_arguments;
input_name = argv[remaining++];
output_name = argv[remaining];
}
/* Special handling if we are asked to print the database. */
if (do_undo)
{
int fd = open (input_name, O_RDONLY);
if (fd == -1)
error (EXIT_FAILURE, errno, gettext ("cannot open database file `%s'"),
input_name);
int status = print_database (fd);
close (fd);
return status;
}
/* Open input file. */
if (strcmp (input_name, "-") == 0 || strcmp (input_name, "/dev/stdin") == 0)
input_file = stdin;
else
{
struct stat64 st;
input_file = fopen64 (input_name, "r");
if (input_file == NULL)
error (EXIT_FAILURE, errno, gettext ("cannot open input file `%s'"),
input_name);
/* Get the access rights from the source file. The output file should
have the same. */
if (fstat64 (fileno (input_file), &st) >= 0)
mode = st.st_mode & ACCESSPERMS;
}
/* Start the real work. */
int status = process_input (input_file, input_name, to_lowercase, be_quiet);
/* Close files. */
if (input_file != stdin)
fclose (input_file);
/* No need to continue when we did not read the file successfully. */
if (status != EXIT_SUCCESS)
return status;
/* Bail out if nothing is to be done. */
if (!any_dbentry)
{
if (be_quiet)
return EXIT_SUCCESS;
else
error (EXIT_SUCCESS, 0, gettext ("no entries to be processed"));
}
/* Compute hash and string tables. */
compute_tables ();
/* Open output file. This must not be standard output so we don't
handle "-" and "/dev/stdout" special. */
char *tmp_output_name;
if (asprintf (&tmp_output_name, "%s.XXXXXX", output_name) == -1)
error (EXIT_FAILURE, errno, gettext ("cannot create temporary file name"));
set_file_creation_context (output_name, mode);
int fd = mkstemp (tmp_output_name);
reset_file_creation_context ();
if (fd == -1)
error (EXIT_FAILURE, errno, gettext ("cannot create temporary file"));
status = write_output (fd);
if (status == EXIT_SUCCESS)
{
struct stat64 st;
if (fstat64 (fd, &st) == 0)
{
if ((st.st_mode & ACCESSPERMS) != mode)
/* We ignore problems with changing the mode. */
fchmod (fd, mode);
}
else
{
error (0, errno, gettext ("cannot stat newly created file"));
status = EXIT_FAILURE;
}
}
close (fd);
if (status == EXIT_SUCCESS)
{
if (rename (tmp_output_name, output_name) != 0)
{
error (0, errno, gettext ("cannot rename temporary file"));
status = EXIT_FAILURE;
goto do_unlink;
}
}
else
do_unlink:
unlink (tmp_output_name);
return status;
}
/* Handle program arguments. */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
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struct db_option *newp;
switch (key)
{
case 'f':
to_lowercase = 1;
break;
case 'o':
output_name = arg;
break;
case 'q':
be_quiet = 1;
break;
case 'u':
do_undo = 1;
break;
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case 'g':
newp = xmalloc (sizeof (*newp));
newp->dbid = arg[0];
newp->next = db_options;
db_options = newp;
break;
default:
return ARGP_ERR_UNKNOWN;
}
return 0;
}
static char *
more_help (int key, const char *text, void *input)
{
char *tp = NULL;
switch (key)
{
case ARGP_KEY_HELP_EXTRA:
/* We print some extra information. */
if (asprintf (&tp, gettext ("\
For bug reporting instructions, please see:\n\
%s.\n"), REPORT_BUGS_TO) < 0)
return NULL;
return tp;
default:
break;
}
return (char *) text;
}
/* Print the version information. */
static void
print_version (FILE *stream, struct argp_state *state)
{
fprintf (stream, "makedb %s%s\n", PKGVERSION, VERSION);
fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions. There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "2013");
fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
}
static int
dbentry_compare (const void *p1, const void *p2)
{
const struct dbentry *d1 = (const struct dbentry *) p1;
const struct dbentry *d2 = (const struct dbentry *) p2;
if (d1->hashval != d2->hashval)
return d1->hashval < d2->hashval ? -1 : 1;
return strcmp (d1->str, d2->str);
}
static int
valstr_compare (const void *p1, const void *p2)
{
const struct valstrentry *d1 = (const struct valstrentry *) p1;
const struct valstrentry *d2 = (const struct valstrentry *) p2;
return strcmp (d1->str, d2->str);
}
static int
process_input (input, inname, to_lowercase, be_quiet)
FILE *input;
const char *inname;
int to_lowercase;
int be_quiet;
{
char *line;
size_t linelen;
int status;
size_t linenr;
line = NULL;
linelen = 0;
status = EXIT_SUCCESS;
linenr = 0;
struct database *last_database = NULL;
while (!feof_unlocked (input))
{
ssize_t n = getline (&line, &linelen, input);
if (n < 0)
/* This means end of file or some bug. */
break;
if (n == 0)
/* Short read. Probably interrupted system call. */
continue;
++linenr;
if (line[n - 1] == '\n')
/* Remove trailing newline. */
line[--n] = '\0';
char *cp = line;
while (isspace (*cp))
++cp;
if (*cp == '#' || *cp == '\0')
/* First non-space character in line '#': it's a comment.
Also go to the next line if it is empty except for whitespaces. */
continue;
/* Skip over the character indicating the database so that it is not
affected by TO_LOWERCASE. */
char *key = cp++;
while (*cp != '\0' && !isspace (*cp))
{
if (to_lowercase)
*cp = tolower (*cp);
++cp;
}
if (*cp == '\0')
/* It's a line without a value field. */
continue;
*cp++ = '\0';
size_t keylen = cp - key;
while (isspace (*cp))
++cp;
char *data = cp;
size_t datalen = (&line[n] - cp) + 1;
/* Find the database. */
if (last_database == NULL || last_database->dbid != key[0])
{
last_database = databases;
while (last_database != NULL && last_database->dbid != key[0])
last_database = last_database->next;
if (last_database == NULL)
{
last_database = xmalloc (sizeof (*last_database));
last_database->dbid = key[0];
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last_database->extra_string = false;
last_database->next = databases;
last_database->entries = NULL;
last_database->nentries = 0;
last_database->keystrlen = 0;
databases = last_database;
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struct db_option *runp = db_options;
while (runp != NULL)
if (runp->dbid == key[0])
{
last_database->extra_string = true;
break;
}
else
runp = runp->next;
}
}
/* Skip the database selector. */
++key;
--keylen;
/* Store the data. */
struct valstrentry *nentry = xmalloc (sizeof (struct valstrentry)
+ datalen);
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if (last_database->extra_string)
nentry->idx = extrastrlen;
else
nentry->idx = valstrlen;
nentry->extra_string = last_database->extra_string;
memcpy (nentry->str, data, datalen);
struct valstrentry **fdata = tsearch (nentry, &valstrtree,
valstr_compare);
if (fdata == NULL)
error (EXIT_FAILURE, errno, gettext ("cannot create search tree"));
if (*fdata != nentry)
{
/* We can reuse a string. */
free (nentry);
nentry = *fdata;
}
else
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if (last_database->extra_string)
extrastrlen += datalen;
else
valstrlen += datalen;
/* Store the key. */
struct dbentry *newp = xmalloc (sizeof (struct dbentry) + keylen);
newp->validx = nentry->idx;
newp->hashval = __hash_string (key);
memcpy (newp->str, key, keylen);
struct dbentry **found = tsearch (newp, &last_database->entries,
dbentry_compare);
if (found == NULL)
error (EXIT_FAILURE, errno, gettext ("cannot create search tree"));
if (*found != newp)
{
free (newp);
if (!be_quiet)
error_at_line (0, 0, inname, linenr, gettext ("duplicate key"));
continue;
}
++last_database->nentries;
last_database->keystrlen += keylen;
any_dbentry = true;
}
if (ferror_unlocked (input))
{
error (0, 0, gettext ("problems while reading `%s'"), inname);
status = EXIT_FAILURE;
}
return status;
}
static void
copy_valstr (const void *nodep, const VISIT which, const int depth)
{
if (which != leaf && which != postorder)
return;
const struct valstrentry *p = *(const struct valstrentry **) nodep;
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strcpy (valstrtab + (p->extra_string ? valstrlen : 0) + p->idx, p->str);
}
/* Determine if the candidate is prime by using a modified trial division
algorithm. The candidate must be both odd and greater than 4. */
static int
is_prime (size_t candidate)
{
size_t divn = 3;
size_t sq = divn * divn;
assert (candidate > 4 && candidate % 2 != 0);
while (sq < candidate && candidate % divn != 0)
{
++divn;
sq += 4 * divn;
++divn;
}
return candidate % divn != 0;
}
static size_t
next_prime (size_t seed)
{
/* Make sure that we're always greater than 4. */
seed = (seed + 4) | 1;
while (!is_prime (seed))
seed += 2;
return seed;
}
static void
compute_tables (void)
{
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valstrtab = xmalloc (roundup (valstrlen + extrastrlen, sizeof (stridx_t)));
while ((valstrlen + extrastrlen) % sizeof (stridx_t) != 0)
valstrtab[valstrlen++] = '\0';
twalk (valstrtree, copy_valstr);
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static struct database *db;
for (db = databases; db != NULL; db = db->next)
if (db->nentries != 0)
{
++ndatabases;
/* We simply use an odd number large than twice the number of
elements to store in the hash table for the size. This gives
enough efficiency. */
#define TEST_RANGE 30
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size_t nhashentries_min = next_prime (db->nentries < TEST_RANGE
? db->nentries
: db->nentries * 2 - TEST_RANGE);
size_t nhashentries_max = MAX (nhashentries_min, db->nentries * 4);
size_t nhashentries_best = nhashentries_min;
size_t chainlength_best = db->nentries;
db->hashtable = xmalloc (2 * nhashentries_max * sizeof (stridx_t)
+ db->keystrlen);
db->keyidxtab = db->hashtable + nhashentries_max;
db->keystrtab = (char *) (db->keyidxtab + nhashentries_max);
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static size_t max_chainlength;
static char *wp;
static size_t nhashentries;
static bool copy_string;
void add_key(const void *nodep, const VISIT which, const int depth)
{
if (which != leaf && which != postorder)
return;
const struct dbentry *dbe = *(const struct dbentry **) nodep;
ptrdiff_t stridx;
if (copy_string)
{
stridx = wp - db->keystrtab;
wp = stpcpy (wp, dbe->str) + 1;
}
else
stridx = 0;
size_t hidx = dbe->hashval % nhashentries;
size_t hval2 = 1 + dbe->hashval % (nhashentries - 2);
size_t chainlength = 0;
while (db->hashtable[hidx] != ~((stridx_t) 0))
{
++chainlength;
if ((hidx += hval2) >= nhashentries)
hidx -= nhashentries;
}
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db->hashtable[hidx] = ((db->extra_string ? valstrlen : 0)
+ dbe->validx);
db->keyidxtab[hidx] = stridx;
max_chainlength = MAX (max_chainlength, chainlength);
}
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copy_string = false;
nhashentries = nhashentries_min;
for (size_t cnt = 0; cnt < TEST_RANGE; ++cnt)
{
memset (db->hashtable, '\xff', nhashentries * sizeof (stridx_t));
max_chainlength = 0;
wp = db->keystrtab;
twalk (db->entries, add_key);
if (max_chainlength == 0)
{
/* No need to look further, this is as good as it gets. */
nhashentries_best = nhashentries;
break;
}
if (max_chainlength < chainlength_best)
{
chainlength_best = max_chainlength;
nhashentries_best = nhashentries;
}
nhashentries = next_prime (nhashentries + 1);
if (nhashentries > nhashentries_max)
break;
}
/* Recompute the best table again, this time fill in the strings. */
nhashentries = nhashentries_best;
memset (db->hashtable, '\xff',
2 * nhashentries_max * sizeof (stridx_t));
copy_string = true;
wp = db->keystrtab;
twalk (db->entries, add_key);
db->nhashentries = nhashentries_best;
nhashentries_total += nhashentries_best;
}
}
static int
write_output (int fd)
{
struct nss_db_header *header;
uint64_t file_offset = (sizeof (struct nss_db_header)
+ (ndatabases * sizeof (header->dbs[0])));
header = alloca (file_offset);
header->magic = NSS_DB_MAGIC;
header->ndbs = ndatabases;
header->valstroffset = file_offset;
header->valstrlen = valstrlen;
size_t filled_dbs = 0;
struct iovec iov[2 + ndatabases * 3];
iov[0].iov_base = header;
iov[0].iov_len = file_offset;
iov[1].iov_base = valstrtab;
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iov[1].iov_len = valstrlen + extrastrlen;
file_offset += iov[1].iov_len;
size_t keydataoffset = file_offset + nhashentries_total * sizeof (stridx_t);
for (struct database *db = databases; db != NULL; db = db->next)
if (db->entries != NULL)
{
assert (file_offset % sizeof (stridx_t) == 0);
assert (filled_dbs < ndatabases);
header->dbs[filled_dbs].id = db->dbid;
memset (header->dbs[filled_dbs].pad, '\0',
sizeof (header->dbs[0].pad));
header->dbs[filled_dbs].hashsize = db->nhashentries;
iov[2 + filled_dbs].iov_base = db->hashtable;
iov[2 + filled_dbs].iov_len = db->nhashentries * sizeof (stridx_t);
header->dbs[filled_dbs].hashoffset = file_offset;
file_offset += iov[2 + filled_dbs].iov_len;
iov[2 + ndatabases + filled_dbs * 2].iov_base = db->keyidxtab;
iov[2 + ndatabases + filled_dbs * 2].iov_len
= db->nhashentries * sizeof (stridx_t);
header->dbs[filled_dbs].keyidxoffset = keydataoffset;
keydataoffset += iov[2 + ndatabases + filled_dbs * 2].iov_len;
iov[3 + ndatabases + filled_dbs * 2].iov_base = db->keystrtab;
iov[3 + ndatabases + filled_dbs * 2].iov_len = db->keystrlen;
header->dbs[filled_dbs].keystroffset = keydataoffset;
keydataoffset += iov[3 + ndatabases + filled_dbs * 2].iov_len;
++filled_dbs;
}
assert (filled_dbs == ndatabases);
assert (file_offset == (iov[0].iov_len + iov[1].iov_len
+ nhashentries_total * sizeof (stridx_t)));
header->allocate = file_offset;
if (writev (fd, iov, 2 + ndatabases * 3) != keydataoffset)
{
error (0, errno, gettext ("failed to write new database file"));
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
static int
print_database (int fd)
{
struct stat64 st;
if (fstat64 (fd, &st) != 0)
error (EXIT_FAILURE, errno, gettext ("cannot stat database file"));
const struct nss_db_header *header = mmap (NULL, st.st_size, PROT_READ,
MAP_PRIVATE|MAP_POPULATE, fd, 0);
if (header == MAP_FAILED)
error (EXIT_FAILURE, errno, gettext ("cannot map database file"));
if (header->magic != NSS_DB_MAGIC)
error (EXIT_FAILURE, 0, gettext ("file not a database file"));
const char *valstrtab = (const char *) header + header->valstroffset;
for (unsigned int dbidx = 0; dbidx < header->ndbs; ++dbidx)
{
const stridx_t *stridxtab
= ((const stridx_t *) ((const char *) header
+ header->dbs[dbidx].keyidxoffset));
const char *keystrtab
= (const char *) header + header->dbs[dbidx].keystroffset;
const stridx_t *hashtab
= (const stridx_t *) ((const char *) header
+ header->dbs[dbidx].hashoffset);
for (uint32_t hidx = 0; hidx < header->dbs[dbidx].hashsize; ++hidx)
if (hashtab[hidx] != ~((stridx_t) 0))
printf ("%c%s %s\n",
header->dbs[dbidx].id,
keystrtab + stridxtab[hidx],
valstrtab + hashtab[hidx]);
}
return EXIT_SUCCESS;
}
#ifdef HAVE_SELINUX
static void
set_file_creation_context (const char *outname, mode_t mode)
{
static int enabled;
static int enforcing;
security_context_t ctx;
/* Check if SELinux is enabled, and remember. */
if (enabled == 0)
enabled = is_selinux_enabled () ? 1 : -1;
if (enabled < 0)
return;
/* Check if SELinux is enforcing, and remember. */
if (enforcing == 0)
enforcing = security_getenforce () ? 1 : -1;
/* Determine the context which the file should have. */
ctx = NULL;
if (matchpathcon (outname, S_IFREG | mode, &ctx) == 0 && ctx != NULL)
{
if (setfscreatecon (ctx) != 0)
error (enforcing > 0 ? EXIT_FAILURE : 0, 0,
gettext ("cannot set file creation context for `%s'"),
outname);
freecon (ctx);
}
}
static void
reset_file_creation_context (void)
{
setfscreatecon (NULL);
}
#endif