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Simon McVittie authored
This makes it easier to tell which version we are dealing with. Signed-off-by:
Simon McVittie <smcv@collabora.com>
Simon McVittie authoredThis makes it easier to tell which version we are dealing with. Signed-off-by:
Simon McVittie <smcv@collabora.com>
inspect-library.c 12.39 KiB
/*
* Copyright © 2019 Collabora Ltd.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* This helper takes a SONAME as an argument, and optionally a filename for
* symbols, and outputs a parsable JSON with the path, the dependencies and
* the possible missing symbols of the requested library.
*
* For a usage example see `srt_check_library_presence` in
* `steam-runtime-tools/library.c`.
*/
#include <argz.h>
#include <dlfcn.h>
#include <errno.h>
#include <getopt.h>
#include <link.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#define BASE "Base"
static void print_json_string_content (const char *s);
static void clean_exit (void *handle);
static bool has_symbol (void *handle, const char *symbol);
static bool has_versioned_symbol (void *handle,
const char *symbol,
const char * version);
static void oom (void) __attribute__((__noreturn__));
static void
oom (void)
{
fprintf (stderr, "Out of memory");
exit (EX_OSERR);
}
#define asprintf_or_die(...) \
do { \
if (asprintf (__VA_ARGS__) < 0) \
oom (); \
} while (0)
#define argz_add_or_die(...) \
do { \
if (argz_add (__VA_ARGS__) != 0) \
oom (); \
} while (0)
enum
{
OPTION_HELP = 1,
OPTION_DEB_SYMBOLS,
OPTION_HIDDEN_DEPENDENCY,
OPTION_VERSION,
};
struct option long_options[] =
{
{ "hidden-dependency", required_argument, NULL, OPTION_HIDDEN_DEPENDENCY },
{ "deb-symbols", no_argument, NULL, OPTION_DEB_SYMBOLS },
{ "help", no_argument, NULL, OPTION_HELP },
{ "version", no_argument, NULL, OPTION_VERSION },
{ NULL, 0, NULL, 0 }
};
static void usage (int code) __attribute__((__noreturn__));
/*
* Print usage information and exit with status @code.
*/
static void
usage (int code)
{
FILE *fp;
if (code == 0)
fp = stdout;
else
fp = stderr;
fprintf (fp, "Usage: %s [OPTIONS] SONAME [SYMBOLS_FILENAME]\n",
program_invocation_short_name);
exit (code);
}
int
main (int argc,
char **argv)
{
const char *entry;
const char *soname;
const char *version;
const char *symbol;
void *handle = NULL;
struct link_map *dep_map = NULL;
struct link_map *the_library = NULL;
FILE *fp;
char *missing_symbols = NULL;
char *misversioned_symbols = NULL;
size_t missing_n = 0;
size_t misversioned_n = 0;
char *line = NULL;
size_t len = 0;
ssize_t chars;
bool first;
bool deb_symbols = false;
size_t dependency_counter = 0;
int opt;
while ((opt = getopt_long (argc, argv, "", long_options, NULL)) != -1)
{
switch (opt)
{
case OPTION_HIDDEN_DEPENDENCY:
dependency_counter++;
break;
case OPTION_DEB_SYMBOLS:
deb_symbols = true;
break;
case OPTION_HELP:
usage (0);
break;
case OPTION_VERSION:
/* Output version number as YAML for machine-readability,
* inspired by `ostree --version` and `docker version` */
printf (
"%s:\n"
" Package: steam-runtime-tools\n"
" Version: %s\n",
argv[0], VERSION);
return 0;
case '?':
default:
usage (1);
break; /* not reached */
}
}
if (argc < optind + 1 || argc > optind + 2)
{
usage (1);
}
const char *hidden_deps[dependency_counter + 1];
if (dependency_counter > 0)
{
/* Reset getopt */
optind = 1;
size_t i = 0;
while ((opt = getopt_long (argc, argv, "", long_options, NULL)) != -1)
{
switch (opt)
{
case OPTION_HIDDEN_DEPENDENCY:
hidden_deps[i] = optarg;
i++;
break;
default:
break;
}
}
}
soname = argv[optind];
printf ("{\n");
printf (" \"");
print_json_string_content (soname);
printf ("\": {");
for (size_t i = 0; i < dependency_counter; i++)
{
/* We don't call "dlclose" on global hidden dependencies, otherwise ubsan
* will report an indirect memory leak */
if (dlopen (hidden_deps[i], RTLD_NOW|RTLD_GLOBAL) == NULL)
{
fprintf (stderr, "Unable to find the dependency library: %s\n", dlerror ());
clean_exit (handle);
return 1;
}
}
handle = dlopen (soname, RTLD_NOW);
if (handle == NULL)
{
fprintf (stderr, "Unable to find the library: %s\n", dlerror ());
clean_exit (handle);
return 1;
}
/* Using RTLD_DI_LINKMAP insted of RTLD_DI_ORIGIN we don't need to worry
* about allocating a big enough array for the path. */
if (dlinfo (handle, RTLD_DI_LINKMAP, &the_library) != 0 || the_library == NULL)
{
fprintf (stderr, "Unable to obtain the path: %s\n", dlerror ());
clean_exit (handle);
return 1;
}
printf ("\n \"path\": \"");
print_json_string_content (the_library->l_name);
printf ("\"");
if (argc >= optind + 2)
{
size_t soname_len = strlen (soname);
bool found_our_soname = false;
bool in_our_soname = false;
if (strcmp(argv[optind + 1], "-") == 0)
fp = stdin;
else
fp = fopen(argv[optind + 1], "r");
if (fp == NULL)
{
int saved_errno = errno;
fprintf (stderr, "Error reading \"%s\": %s\n",
argv[optind + 1], strerror (saved_errno));
clean_exit (handle);
return 1;
}
while ((chars = getline(&line, &len, fp)) != -1)
{
if (line[chars - 1] == '\n')
line[chars - 1] = '\0';
/* Skip any empty line */
if (chars > 1)
{
char *pointer_into_line;
if (deb_symbols)
{
if (line[0] == '#' || line[0] == '*' || line[0] == '|')
{
/* comment or metadata lines, ignore:
* "# comment"
* "* Field: Value"
* "| alternative-dependency" */
continue;
}
else if (line[0] == ' ')
{
/* this line represents a symbol:
* " symbol@Base 1.2-3~" */
if (!in_our_soname)
{
/* this is a symbol from a different library,
* ignore */
continue;
}
}
else
{
/* This line introduces a new SONAME, which might
* be the one we are interested in:
* "libz.so.1 zlib1g #MINVER#" */
if (strncmp (soname, line, soname_len) == 0
&& (line[soname_len] == ' ' || line[soname_len] == '\t'))
{
found_our_soname = true;
in_our_soname = true;
}
else
{
in_our_soname = false;
}
/* This is not a symbol */
continue;
}
pointer_into_line = &line[1];
}
else
{
pointer_into_line = line;
}
symbol = strsep (&pointer_into_line, "@");
version = strsep (&pointer_into_line, deb_symbols ? "@ \t" : "@");
if (symbol == NULL)
{
fprintf (stderr, "Probably the symbol@version pair is mispelled.");
free (line);
free (missing_symbols);
free (misversioned_symbols);
clean_exit (handle);
return 1;
}
if (version == NULL || strcmp (version, BASE) == 0)
{
if (!has_symbol (handle, symbol))
argz_add_or_die (&missing_symbols, &missing_n, symbol);
}
else
{
if (!has_versioned_symbol (handle, symbol, version))
{
char * merged_string;
asprintf_or_die (&merged_string, "%s@%s", symbol, version);
if (has_symbol (handle, symbol))
argz_add_or_die (&misversioned_symbols, &misversioned_n, merged_string);
else
argz_add_or_die (&missing_symbols, &missing_n, merged_string);
free (merged_string);
}
}
}
}
free (line);
fclose (fp);
if (deb_symbols && !found_our_soname)
{
fprintf (stderr, "Warning: \"%s\" does not describe ABI of \"%s\"\n",
argv[optind + 1], soname);
}
first = true;
entry = 0;
printf (",\n \"missing_symbols\": [");
while ((entry = argz_next (missing_symbols, missing_n, entry)))
{
if (first)
first = false;
else
printf (",");
printf ("\n \"");
print_json_string_content (entry);
printf ("\"");
}
printf ("\n ]");
first = true;
entry = 0;
printf (",\n \"misversioned_symbols\": [");
while ((entry = argz_next (misversioned_symbols, misversioned_n, entry)))
{
if (first)
first = false;
else
printf (",");
printf ("\n \"");
print_json_string_content (entry);
printf ("\"");
}
printf ("\n ]");
free (missing_symbols);
free (misversioned_symbols);
}
dep_map = the_library;
/* Some loaded libraries may be before our handle.
* To list them all we move the pointer at the beginning. */
while (dep_map != NULL && dep_map->l_prev != NULL)
dep_map = dep_map->l_prev;
printf (",\n \"dependencies\": [");
first = true;
for (; dep_map != NULL; dep_map = dep_map->l_next)
{
if (dep_map == the_library || strcmp (dep_map->l_name, "") == 0)
continue;
if (first)
{
printf ("\n \"");
first = false;
}
else
printf (",\n \"");
print_json_string_content (dep_map->l_name);
printf ("\"");
}
printf ("\n ]\n }");
clean_exit (handle);
return 0;
}
static void
print_json_string_content (const char *s)
{
const char *p;
for (p = s; *p != '\0'; p++)
{
if (*p == '"' || *p == '\\' || *p <= 0x1F)
printf ("\\u%04x", *p);
else
printf ("%c", *p);
}
}
static void
clean_exit (void *handle)
{
if (handle != NULL)
dlclose (handle);
printf ("\n}\n");
}
static bool
has_symbol (void *handle,
const char *symbol)
{
(void) dlerror (); /* clear old error indicator */
(void) dlsym (handle, symbol);
return (dlerror () == NULL);
}
static bool
has_versioned_symbol (void *handle,
const char *symbol,
const char *version)
{
(void) dlerror (); /* clear old error indicator */
(void) dlvsym (handle, symbol, version);
return (dlerror () == NULL);
}