/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "util.h"
#include "libconstants.h"
#include "libsyscalls.h"
/*
* These are syscalls used by the syslog() C library call. You can find them
* by running a simple test program. See below for x86_64 behavior:
* $ cat test.c
* #include <syslog.h>
* main() { syslog(0, "foo"); }
* $ gcc test.c -static
* $ strace ./a.out
* ...
* socket(PF_FILE, SOCK_DGRAM|SOCK_CLOEXEC, 0) = 3 <- look for socket connection
* connect(...) <- important
* sendto(...) <- important
* exit_group(0) <- finish!
*/
#if defined(__x86_64__)
#if defined(__ANDROID__)
const char *log_syscalls[] = {"socket", "connect", "fcntl", "writev"};
#else
const char *log_syscalls[] = {"connect", "sendto"};
#endif
#elif defined(__i386__)
#if defined(__ANDROID__)
const char *log_syscalls[] = {"socketcall", "writev", "fcntl64",
"clock_gettime"};
#else
const char *log_syscalls[] = {"socketcall", "time"};
#endif
#elif defined(__arm__)
#if defined(__ANDROID__)
const char *log_syscalls[] = {"clock_gettime", "connect", "fcntl64", "socket",
"writev"};
#else
const char *log_syscalls[] = {"connect", "gettimeofday", "send"};
#endif
#elif defined(__aarch64__)
#if defined(__ANDROID__)
const char *log_syscalls[] = {"connect", "fcntl", "sendto", "socket", "writev"};
#else
const char *log_syscalls[] = {"connect", "send"};
#endif
#elif defined(__powerpc__) || defined(__ia64__) || defined(__hppa__) || \
defined(__sparc__) || defined(__mips__)
const char *log_syscalls[] = {"connect", "send"};
#else
#error "Unsupported platform"
#endif
const size_t log_syscalls_len = ARRAY_SIZE(log_syscalls);
int lookup_syscall(const char *name)
{
const struct syscall_entry *entry = syscall_table;
for (; entry->name && entry->nr >= 0; ++entry)
if (!strcmp(entry->name, name))
return entry->nr;
return -1;
}
const char *lookup_syscall_name(int nr)
{
const struct syscall_entry *entry = syscall_table;
for (; entry->name && entry->nr >= 0; ++entry)
if (entry->nr == nr)
return entry->name;
return NULL;
}
long int parse_single_constant(char *constant_str, char **endptr)
{
const struct constant_entry *entry = constant_table;
long int res = 0;
for (; entry->name; ++entry) {
if (!strcmp(entry->name, constant_str)) {
if (endptr)
*endptr = constant_str + strlen(constant_str);
return entry->value;
}
}
errno = 0;
res = strtol(constant_str, endptr, 0);
if (errno == ERANGE) {
if (res == LONG_MAX) {
/* See if the constant fits in an unsigned long int. */
errno = 0;
res = strtoul(constant_str, endptr, 0);
if (errno == ERANGE) {
/*
* On unsigned overflow, use the same convention
* as when strtol(3) finds no digits: set
* |*endptr| to |constant_str| and return 0.
*/
warn("unsigned overflow: '%s'", constant_str);
*endptr = constant_str;
res = 0;
}
} else if (res == LONG_MIN) {
/*
* Same for signed underflow: set |*endptr| to
* |constant_str| and return 0.
*/
warn("signed underflow: '%s'", constant_str);
*endptr = constant_str;
res = 0;
}
}
return res;
}
long int parse_constant(char *constant_str, char **endptr)
{
long int value = 0;
char *group, *lastpos = constant_str;
char *original_constant_str = constant_str;
/*
* Try to parse constants separated by pipes. Note that since
* |constant_str| is an atom, there can be no spaces between the
* constant and the pipe. Constants can be either a named constant
* defined in libconstants.gen.c or a number parsed with strtol(3).
*
* If there is an error parsing any of the constants, the whole process
* fails.
*/
while ((group = tokenize(&constant_str, "|")) != NULL) {
char *end = group;
value |= parse_single_constant(group, &end);
if (end == group) {
lastpos = original_constant_str;
value = 0;
break;
}
lastpos = end;
}
if (endptr)
*endptr = lastpos;
return value;
}
/*
* parse_size, specified as a string with a decimal number in bytes,
* possibly with one 1-character suffix like "10K" or "6G".
* Assumes both pointers are non-NULL.
*
* Returns 0 on success, negative errno on failure.
* Only writes to result on success.
*/
int parse_size(size_t *result, const char *sizespec)
{
const char prefixes[] = "KMGTPE";
size_t i, multiplier = 1, nsize, size = 0;
unsigned long long parsed;
const size_t len = strlen(sizespec);
char *end;
if (len == 0 || sizespec[0] == '-')
return -EINVAL;
for (i = 0; i < sizeof(prefixes); ++i) {
if (sizespec[len - 1] == prefixes[i]) {
#if __WORDSIZE == 32
if (i >= 3)
return -ERANGE;
#endif
multiplier = 1024;
while (i-- > 0)
multiplier *= 1024;
break;
}
}
/* We only need size_t but strtoul(3) is too small on IL32P64. */
parsed = strtoull(sizespec, &end, 10);
if (parsed == ULLONG_MAX)
return -errno;
if (parsed >= SIZE_MAX)
return -ERANGE;
if ((multiplier != 1 && end != sizespec + len - 1) ||
(multiplier == 1 && end != sizespec + len))
return -EINVAL;
size = (size_t)parsed;
nsize = size * multiplier;
if (nsize / multiplier != size)
return -ERANGE;
*result = nsize;
return 0;
}
char *strip(char *s)
{
char *end;
while (*s && isblank(*s))
s++;
end = s + strlen(s) - 1;
while (end >= s && *end && (isblank(*end) || *end == '\n'))
end--;
*(end + 1) = '\0';
return s;
}
char *tokenize(char **stringp, const char *delim)
{
char *ret = NULL;
/* If the string is NULL or empty, there are no tokens to be found. */
if (stringp == NULL || *stringp == NULL || **stringp == '\0')
return NULL;
/*
* If the delimiter is NULL or empty,
* the full string makes up the only token.
*/
if (delim == NULL || *delim == '\0') {
ret = *stringp;
*stringp = NULL;
return ret;
}
char *found;
while (**stringp != '\0') {
found = strstr(*stringp, delim);
if (!found) {
/*
* The delimiter was not found, so the full string
* makes up the only token, and we're done.
*/
ret = *stringp;
*stringp = NULL;
break;
}
if (found != *stringp) {
/* There's a non-empty token before the delimiter. */
*found = '\0';
ret = *stringp;
*stringp = found + strlen(delim);
break;
}
/*
* The delimiter was found at the start of the string,
* skip it and keep looking for a non-empty token.
*/
*stringp += strlen(delim);
}
return ret;
}
char *path_join(const char *external_path, const char *internal_path)
{
char *path;
size_t pathlen;
/* One extra char for '/' and one for '\0', hence + 2. */
pathlen = strlen(external_path) + strlen(internal_path) + 2;
path = malloc(pathlen);
snprintf(path, pathlen, "%s/%s", external_path, internal_path);
return path;
}
int write_proc_file(pid_t pid, const char *content, const char *basename)
{
int fd, ret;
size_t sz, len;
ssize_t written;
char filename[32];
sz = sizeof(filename);
ret = snprintf(filename, sz, "/proc/%d/%s", pid, basename);
if (ret < 0 || (size_t)ret >= sz) {
warn("failed to generate %s filename", basename);
return -1;
}
fd = open(filename, O_WRONLY | O_CLOEXEC);
if (fd < 0) {
pwarn("failed to open '%s'", filename);
return -errno;
}
len = strlen(content);
written = write(fd, content, len);
if (written < 0) {
pwarn("failed to write '%s'", filename);
return -1;
}
if ((size_t)written < len) {
warn("failed to write %zu bytes to '%s'", len, filename);
return -1;
}
close(fd);
return 0;
}
int write_pid_to_path(pid_t pid, const char *path)
{
FILE *fp = fopen(path, "w");
if (!fp) {
pwarn("failed to open '%s'", path);
return -errno;
}
if (fprintf(fp, "%d\n", (int)pid) < 0) {
/* fprintf(3) does not set errno on failure. */
warn("fprintf(%s) failed", path);
return -1;
}
if (fclose(fp)) {
pwarn("fclose(%s) failed", path);
return -errno;
}
return 0;
}
void *consumebytes(size_t length, char **buf, size_t *buflength)
{
char *p = *buf;
if (length > *buflength)
return NULL;
*buf += length;
*buflength -= length;
return p;
}
char *consumestr(char **buf, size_t *buflength)
{
size_t len = strnlen(*buf, *buflength);
if (len == *buflength)
/* There's no null-terminator. */
return NULL;
return consumebytes(len + 1, buf, buflength);
}