Refactor out the 'find string at start of any line' logic.

We do this in too many places throughout the code; it's time to start
clamping down.

Also, refactor Karsten's patch to use strchr-then-strndup, rather than
malloc-then-strlcpy-then-strchr-then-clear.
This commit is contained in:
Nick Mathewson 2009-12-17 18:29:37 -05:00
parent 498c293afe
commit 235f1e1a96
4 changed files with 77 additions and 29 deletions

View File

@ -682,6 +682,29 @@ find_whitespace_eos(const char *s, const char *eos)
return s;
}
/** Return the the first occurrence of <b>needle</b> in <b>haystack</b> that
* occurs at the start of a line (that is, at the beginning of <b>haystack</b>
* or immediately after a newline). Return NULL if no such string is found.
*/
const char *
find_str_at_start_of_line(const char *haystack, const char *needle)
{
size_t needle_len = strlen(needle);
do {
if (!strncmp(haystack, needle, needle_len))
return haystack;
haystack = strchr(haystack, '\n');
if (!haystack)
return NULL;
else
++haystack;
} while (*haystack);
return NULL;
}
/** Return true iff the 'len' bytes at 'mem' are all zero. */
int
tor_mem_is_zero(const char *mem, size_t len)

View File

@ -195,6 +195,8 @@ const char *eat_whitespace_no_nl(const char *s) ATTR_PURE;
const char *eat_whitespace_eos_no_nl(const char *s, const char *eos) ATTR_PURE;
const char *find_whitespace(const char *s) ATTR_PURE;
const char *find_whitespace_eos(const char *s, const char *eos) ATTR_PURE;
const char *find_str_at_start_of_line(const char *haystack, const char *needle)
ATTR_PURE;
int tor_mem_is_zero(const char *mem, size_t len) ATTR_PURE;
int tor_digest_is_zero(const char *digest) ATTR_PURE;
int tor_digest256_is_zero(const char *digest) ATTR_PURE;

View File

@ -1099,11 +1099,10 @@ parse_bridge_stats_controller(const char *stats_str, time_t now)
{
char stats_end_str[ISO_TIME_LEN+1], stats_start_str[ISO_TIME_LEN+1],
*controller_str, *eos, *eol, *summary;
const char *stats_end_first = "bridge-stats-end ",
*stats_end_middle = "\nbridge-stats-end ",
*ips_first = "bridge-ips",
*ips_middle = "\nbridge-ips",
*tmp;
const char *BRIDGE_STATS_END = "bridge-stats-end ";
const char *BRIDGE_IPS = "bridge-ips ";
const char *tmp;
time_t stats_end_time;
size_t controller_len;
int seconds;
@ -1111,14 +1110,11 @@ parse_bridge_stats_controller(const char *stats_str, time_t now)
/* Parse timestamp and number of seconds from
"bridge-stats-end YYYY-MM-DD HH:MM:SS (N s)" */
if (!strncmp(stats_str, stats_end_first, strlen(stats_end_first))) {
tmp = stats_str + strlen(stats_end_first);
} else {
tmp = strstr(stats_str, stats_end_middle);
if (!tmp)
return NULL;
tmp += strlen(stats_end_middle);
}
tmp = find_str_at_start_of_line(stats_str, BRIDGE_STATS_END);
if (!tmp)
return NULL;
tmp += strlen(BRIDGE_STATS_END);
if (strlen(tmp) < ISO_TIME_LEN + 6)
return NULL;
strlcpy(stats_end_str, tmp, sizeof(stats_end_str));
@ -1133,23 +1129,19 @@ parse_bridge_stats_controller(const char *stats_str, time_t now)
format_iso_time(stats_start_str, stats_end_time - seconds);
/* Parse: "bridge-ips CC=N,CC=N,..." */
if (!strncmp(stats_str, ips_first, strlen(ips_first))) {
tmp = stats_str + strlen(ips_first);
} else {
tmp = strstr(stats_str, ips_middle);
if (!tmp)
return NULL;
tmp += strlen(ips_middle);
}
if (strlen(tmp) > 2 && !strncmp(tmp, " ", 1))
tmp += 1;
else
tmp = "";
summary = tor_malloc(strlen(tmp) + 1);
strlcpy(summary, tmp, strlen(tmp) + 1);
eol = strstr(summary, "\n");
tmp = find_str_at_start_of_line(stats_str, BRIDGE_IPS);
if (!tmp)
return NULL;
tmp += strlen(BRIDGE_IPS);
tmp = eat_whitespace_no_nl(tmp);
eol = strchr(tmp, '\n');
if (eol)
eol[0] = '\0';
summary = tor_strndup(tmp, eol-tmp);
else
summary = tor_strdup(tmp);
controller_len = strlen("TimeStarted=\"\" CountrySummary=") +
strlen(summary) + 42;
controller_str = tor_malloc(controller_len);

View File

@ -1023,9 +1023,39 @@ test_util_strtok(void)
;
}
static void
test_util_find_str_at_start_of_line(void *ptr)
{
const char *long_string =
"hello world. hello world. hello hello. howdy.\n"
"hello hello world\n";
(void)ptr;
/* not-found case. */
tt_assert(! find_str_at_start_of_line(long_string, "fred"));
/* not-found case where haystack doesn't end with \n */
tt_assert(! find_str_at_start_of_line("foobar\nbaz", "fred"));
/* start-of-string case */
tt_assert(long_string ==
find_str_at_start_of_line(long_string, "hello world."));
/* start-of-line case */
tt_assert(strchr(long_string,'\n')+1 ==
find_str_at_start_of_line(long_string, "hello hello"));
done:
;
}
#define UTIL_LEGACY(name) \
{ #name, legacy_test_helper, 0, &legacy_setup, test_util_ ## name }
#define UTIL_TEST(name, flags) \
{ #name, test_util_ ## name, flags, NULL, NULL }
struct testcase_t util_tests[] = {
UTIL_LEGACY(time),
UTIL_LEGACY(config_line),
@ -1040,6 +1070,7 @@ struct testcase_t util_tests[] = {
UTIL_LEGACY(threads),
UTIL_LEGACY(sscanf),
UTIL_LEGACY(strtok),
UTIL_TEST(find_str_at_start_of_line, 0),
END_OF_TESTCASES
};