/*
* Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#include "nsig.h"
typedef unsigned int number_slot_t;
#define BITS_PER_SLOT (sizeof(number_slot_t) * 8)
struct number_set {
number_slot_t *vec;
unsigned int nslots;
bool not;
};
struct number_set read_set;
struct number_set write_set;
struct number_set signal_set;
static struct number_set abbrev_set[SUPPORTED_PERSONALITIES];
static struct number_set inject_set[SUPPORTED_PERSONALITIES];
static struct number_set raw_set[SUPPORTED_PERSONALITIES];
static struct number_set trace_set[SUPPORTED_PERSONALITIES];
static struct number_set verbose_set[SUPPORTED_PERSONALITIES];
static void
number_setbit(const unsigned int i, number_slot_t *const vec)
{
vec[i / BITS_PER_SLOT] |= (number_slot_t) 1 << (i % BITS_PER_SLOT);
}
static bool
number_isset(const unsigned int i, const number_slot_t *const vec)
{
return vec[i / BITS_PER_SLOT] & ((number_slot_t) 1 << (i % BITS_PER_SLOT));
}
static void
reallocate_number_set(struct number_set *const set, const unsigned int new_nslots)
{
if (new_nslots <= set->nslots)
return;
set->vec = xreallocarray(set->vec, new_nslots, sizeof(*set->vec));
memset(set->vec + set->nslots, 0,
sizeof(*set->vec) * (new_nslots - set->nslots));
set->nslots = new_nslots;
}
static void
add_number_to_set(const unsigned int number, struct number_set *const set)
{
reallocate_number_set(set, number / BITS_PER_SLOT + 1);
number_setbit(number, set->vec);
}
bool
is_number_in_set(const unsigned int number, const struct number_set *const set)
{
return ((number / BITS_PER_SLOT < set->nslots)
&& number_isset(number, set->vec)) ^ set->not;
}
typedef int (*string_to_uint_func)(const char *);
/*
* Add numbers to SET according to STR specification.
*/
static void
qualify_tokens(const char *const str, struct number_set *const set,
string_to_uint_func func, const char *const name)
{
/* Clear the set. */
if (set->nslots)
memset(set->vec, 0, sizeof(*set->vec) * set->nslots);
set->not = false;
/*
* Each leading ! character means inversion
* of the remaining specification.
*/
const char *s = str;
handle_inversion:
while (*s == '!') {
set->not = !set->not;
++s;
}
if (strcmp(s, "none") == 0) {
/*
* No numbers are added to the set.
* Subsequent is_number_in_set invocations will return set->not.
*/
return;
} else if (strcmp(s, "all") == 0) {
s = "!none";
goto handle_inversion;
}
/*
* Split the string into comma separated tokens.
* For each token, find out the corresponding number
* by calling FUNC, and add that number to the set.
* The absence of tokens or a negative answer
* from FUNC is a fatal error.
*/
char *copy = xstrdup(s);
char *saveptr = NULL;
const char *token;
int number = -1;
for (token = strtok_r(copy, ",", &saveptr); token;
token = strtok_r(NULL, ",", &saveptr)) {
number = func(token);
if (number < 0) {
error_msg_and_die("invalid %s '%s'", name, token);
}
add_number_to_set(number, set);
}
free(copy);
if (number < 0) {
error_msg_and_die("invalid %s '%s'", name, str);
}
}
static int
sigstr_to_uint(const char *s)
{
int i;
if (*s >= '0' && *s <= '9')
return string_to_uint_upto(s, 255);
if (strncasecmp(s, "SIG", 3) == 0)
s += 3;
for (i = 0; i <= 255; ++i) {
const char *name = signame(i);
if (strncasecmp(name, "SIG", 3) != 0)
continue;
name += 3;
if (strcasecmp(name, s) != 0)
continue;
return i;
}
return -1;
}
static bool
qualify_syscall_number(const char *s, struct number_set *set)
{
int n = string_to_uint(s);
if (n < 0)
return false;
unsigned int p;
bool done = false;
for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
if ((unsigned) n >= nsyscall_vec[p]) {
continue;
}
add_number_to_set(n, &set[p]);
done = true;
}
return done;
}
static unsigned int
lookup_class(const char *s)
{
static const struct {
const char *name;
unsigned int value;
} syscall_class[] = {
{ "desc", TRACE_DESC },
{ "file", TRACE_FILE },
{ "memory", TRACE_MEMORY },
{ "process", TRACE_PROCESS },
{ "signal", TRACE_SIGNAL },
{ "ipc", TRACE_IPC },
{ "network", TRACE_NETWORK },
};
unsigned int i;
for (i = 0; i < ARRAY_SIZE(syscall_class); ++i) {
if (strcmp(s, syscall_class[i].name) == 0) {
return syscall_class[i].value;
}
}
return 0;
}
static bool
qualify_syscall_class(const char *s, struct number_set *set)
{
const unsigned int n = lookup_class(s);
if (!n)
return false;
unsigned int p;
for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
unsigned int i;
for (i = 0; i < nsyscall_vec[p]; ++i) {
if (!sysent_vec[p][i].sys_name
|| (sysent_vec[p][i].sys_flags & n) != n) {
continue;
}
add_number_to_set(i, &set[p]);
}
}
return true;
}
static bool
qualify_syscall_name(const char *s, struct number_set *set)
{
unsigned int p;
bool found = false;
for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
unsigned int i;
for (i = 0; i < nsyscall_vec[p]; ++i) {
if (!sysent_vec[p][i].sys_name
|| strcmp(s, sysent_vec[p][i].sys_name)) {
continue;
}
add_number_to_set(i, &set[p]);
found = true;
}
}
return found;
}
static bool
qualify_syscall(const char *token, struct number_set *set)
{
if (*token >= '0' && *token <= '9')
return qualify_syscall_number(token, set);
return qualify_syscall_class(token, set)
|| qualify_syscall_name(token, set);
}
/*
* Add syscall numbers to SETs for each supported personality
* according to STR specification.
*/
static void
qualify_syscall_tokens(const char *const str, struct number_set *const set,
const char *const name)
{
/* Clear all sets. */
unsigned int p;
for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
if (set[p].nslots)
memset(set[p].vec, 0,
sizeof(*set[p].vec) * set[p].nslots);
set[p].not = false;
}
/*
* Each leading ! character means inversion
* of the remaining specification.
*/
const char *s = str;
handle_inversion:
while (*s == '!') {
for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
set[p].not = !set[p].not;
}
++s;
}
if (strcmp(s, "none") == 0) {
/*
* No syscall numbers are added to sets.
* Subsequent is_number_in_set invocations
* will return set[p]->not.
*/
return;
} else if (strcmp(s, "all") == 0) {
s = "!none";
goto handle_inversion;
}
/*
* Split the string into comma separated tokens.
* For each token, call qualify_syscall that will take care
* if adding appropriate syscall numbers to sets.
* The absence of tokens or a negative return code
* from qualify_syscall is a fatal error.
*/
char *copy = xstrdup(s);
char *saveptr = NULL;
const char *token;
bool done = false;
for (token = strtok_r(copy, ",", &saveptr); token;
token = strtok_r(NULL, ",", &saveptr)) {
done = qualify_syscall(token, set);
if (!done) {
error_msg_and_die("invalid %s '%s'", name, token);
}
}
free(copy);
if (!done) {
error_msg_and_die("invalid %s '%s'", name, str);
}
}
/*
* Returns NULL if STR does not start with PREFIX,
* or a pointer to the first char in STR after PREFIX.
*/
static const char *
strip_prefix(const char *prefix, const char *str)
{
size_t len = strlen(prefix);
return strncmp(prefix, str, len) ? NULL : str + len;
}
static int
find_errno_by_name(const char *name)
{
unsigned int i;
for (i = 1; i < nerrnos; ++i) {
if (errnoent[i] && (strcasecmp(name, errnoent[i]) == 0))
return i;
}
return -1;
}
static bool
parse_inject_token(const char *const token, struct inject_opts *const fopts,
const bool fault_tokens_only)
{
const char *val;
int intval;
if ((val = strip_prefix("when=", token))) {
/*
* == 1+1
* F == F+0
* F+ == F+1
* F+S
*/
char *end;
intval = string_to_uint_ex(val, &end, 0xffff, "+");
if (intval < 1)
return false;
fopts->first = intval;
if (*end) {
val = end + 1;
if (*val) {
/* F+S */
intval = string_to_uint_upto(val, 0xffff);
if (intval < 1)
return false;
fopts->step = intval;
} else {
/* F+ == F+1 */
fopts->step = 1;
}
} else {
/* F == F+0 */
fopts->step = 0;
}
} else if ((val = strip_prefix("error=", token))) {
if (fopts->rval != INJECT_OPTS_RVAL_DEFAULT)
return false;
intval = string_to_uint_upto(val, MAX_ERRNO_VALUE);
if (intval < 0)
intval = find_errno_by_name(val);
if (intval < 1)
return false;
fopts->rval = -intval;
} else if (!fault_tokens_only && (val = strip_prefix("retval=", token))) {
if (fopts->rval != INJECT_OPTS_RVAL_DEFAULT)
return false;
intval = string_to_uint(val);
if (intval < 0)
return false;
fopts->rval = intval;
} else if (!fault_tokens_only && (val = strip_prefix("signal=", token))) {
intval = sigstr_to_uint(val);
if (intval < 1 || intval > NSIG_BYTES * 8)
return false;
fopts->signo = intval;
} else {
return false;
}
return true;
}
static char *
parse_inject_expression(const char *const s, char **buf,
struct inject_opts *const fopts,
const bool fault_tokens_only)
{
char *saveptr = NULL;
char *name = NULL;
char *token;
*buf = xstrdup(s);
for (token = strtok_r(*buf, ":", &saveptr); token;
token = strtok_r(NULL, ":", &saveptr)) {
if (!name)
name = token;
else if (!parse_inject_token(token, fopts, fault_tokens_only))
goto parse_error;
}
if (name)
return name;
parse_error:
free(*buf);
return *buf = NULL;
}
static void
qualify_read(const char *const str)
{
qualify_tokens(str, &read_set, string_to_uint, "descriptor");
}
static void
qualify_write(const char *const str)
{
qualify_tokens(str, &write_set, string_to_uint, "descriptor");
}
static void
qualify_signals(const char *const str)
{
qualify_tokens(str, &signal_set, sigstr_to_uint, "signal");
}
static void
qualify_trace(const char *const str)
{
qualify_syscall_tokens(str, trace_set, "system call");
}
static void
qualify_abbrev(const char *const str)
{
qualify_syscall_tokens(str, abbrev_set, "system call");
}
static void
qualify_verbose(const char *const str)
{
qualify_syscall_tokens(str, verbose_set, "system call");
}
static void
qualify_raw(const char *const str)
{
qualify_syscall_tokens(str, raw_set, "system call");
}
static void
qualify_inject_common(const char *const str,
const bool fault_tokens_only,
const char *const description)
{
struct inject_opts opts = {
.first = 1,
.step = 1,
.rval = INJECT_OPTS_RVAL_DEFAULT,
.signo = 0
};
char *buf = NULL;
char *name = parse_inject_expression(str, &buf, &opts, fault_tokens_only);
if (!name) {
error_msg_and_die("invalid %s '%s'", description, str);
}
/* If neither of retval, error, or signal is specified, then ... */
if (opts.rval == INJECT_OPTS_RVAL_DEFAULT && !opts.signo) {
if (fault_tokens_only) {
/* in fault= syntax the default error code is ENOSYS. */
opts.rval = -ENOSYS;
} else {
/* in inject= syntax this is not allowed. */
error_msg_and_die("invalid %s '%s'", description, str);
}
}
struct number_set tmp_set[SUPPORTED_PERSONALITIES];
memset(tmp_set, 0, sizeof(tmp_set));
qualify_syscall_tokens(name, tmp_set, description);
free(buf);
/*
* Initialize inject_vec accourding to tmp_set.
* Merge tmp_set into inject_set.
*/
unsigned int p;
for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) {
if (!tmp_set[p].nslots && !tmp_set[p].not) {
continue;
}
if (!inject_vec[p]) {
inject_vec[p] = xcalloc(nsyscall_vec[p],
sizeof(*inject_vec[p]));
}
unsigned int i;
for (i = 0; i < nsyscall_vec[p]; ++i) {
if (is_number_in_set(i, &tmp_set[p])) {
add_number_to_set(i, &inject_set[p]);
inject_vec[p][i] = opts;
}
}
free(tmp_set[p].vec);
}
}
static void
qualify_fault(const char *const str)
{
qualify_inject_common(str, true, "fault argument");
}
static void
qualify_inject(const char *const str)
{
qualify_inject_common(str, false, "inject argument");
}
static const struct qual_options {
const char *name;
void (*qualify)(const char *);
} qual_options[] = {
{ "trace", qualify_trace },
{ "t", qualify_trace },
{ "abbrev", qualify_abbrev },
{ "a", qualify_abbrev },
{ "verbose", qualify_verbose },
{ "v", qualify_verbose },
{ "raw", qualify_raw },
{ "x", qualify_raw },
{ "signal", qualify_signals },
{ "signals", qualify_signals },
{ "s", qualify_signals },
{ "read", qualify_read },
{ "reads", qualify_read },
{ "r", qualify_read },
{ "write", qualify_write },
{ "writes", qualify_write },
{ "w", qualify_write },
{ "fault", qualify_fault },
{ "inject", qualify_inject },
};
void
qualify(const char *str)
{
const struct qual_options *opt = qual_options;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(qual_options); ++i) {
const char *p = qual_options[i].name;
unsigned int len = strlen(p);
if (strncmp(str, p, len) || str[len] != '=')
continue;
opt = &qual_options[i];
str += len + 1;
break;
}
opt->qualify(str);
}
unsigned int
qual_flags(const unsigned int scno)
{
return (is_number_in_set(scno, &trace_set[current_personality])
? QUAL_TRACE : 0)
| (is_number_in_set(scno, &abbrev_set[current_personality])
? QUAL_ABBREV : 0)
| (is_number_in_set(scno, &verbose_set[current_personality])
? QUAL_VERBOSE : 0)
| (is_number_in_set(scno, &raw_set[current_personality])
? QUAL_RAW : 0)
| (is_number_in_set(scno, &inject_set[current_personality])
? QUAL_INJECT : 0);
}