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Fix an overflow when counting rejects for *, truncate exit summaries after 1000 chars

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svn:r16530
This commit is contained in:
Peter Palfrader 2008-08-13 19:25:18 +00:00
parent 864b4a009d
commit 171a7d4b0f
4 changed files with 80 additions and 2 deletions
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7
doc/spec/proposals/141-jit-sd-downloads.txt
View File

@ -246,6 +246,13 @@ Status: Draft
of "80-88,89-100" there only is a single item of "80-100", similarly
instead of "20,21" a summary will say "20-21".
Port lists are sorted in ascending order.
The maximum allowed length of a policy summary (including the "accept "
or "reject ") is 1000 characters. If a summary exceeds that length we
use an accept-style summary and list as much of the port list as is
possible within these 1000 bytes.
Similarly to IP address, ports, and timestamp a consensus should list
the exit policy matching the descriptor digest referenced in the
consensus document (See dir-spec section 3.4).

13
src/or/or.h
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@ -3208,11 +3208,19 @@ download_status_is_ready(download_status_t *dls, time_t now,
}
/********************************* dirserv.c ***************************/
/** Maximum length of an exit policy summary. */
#define MAX_EXITPOLICY_SUMMARY_LEN (1000)
/** Maximum allowable length of a version line in a networkstatus. */
#define MAX_V_LINE_LEN 128
/** Length of "r Authority BadDirectory BadExit Exit Fast Guard HSDir Named
* Running Stable Unnamed V2Dir Valid\n". */
#define MAX_FLAG_LINE_LEN 96
/** Length of "w" line for weighting. Currently at most
* "w Bandwidth=<uint32t>\n" */
#define MAX_WEIGHT_LINE_LEN (13+10)
/** Maximum length of an exit policy summary line. */
#define MAX_POLICY_LINE_LEN (3+MAX_EXITPOLICY_SUMMARY_LEN)
/** Amount of space to allocate for each entry: r, s, and v lines. */
#define RS_ENTRY_LEN \
( /* first line */ \
@ -3220,6 +3228,10 @@ download_status_is_ready(download_status_t *dls, time_t now,
5*2 /* ports */ + 10 /* punctuation */ + \
/* second line */ \
MAX_FLAG_LINE_LEN + \
/* weight line */ \
MAX_WEIGHT_LINE_LEN + \
/* p line. */ \
MAX_POLICY_LINE_LEN + \
/* v line. */ \
MAX_V_LINE_LEN \
)
@ -4108,6 +4120,7 @@ routerinfo_t *router_find_exact_exit_enclave(const char *address,
int router_is_unreliable(routerinfo_t *router, int need_uptime,
int need_capacity, int need_guard);
uint32_t router_get_advertised_bandwidth(routerinfo_t *router);
uint32_t router_get_advertised_bandwidth_capped(routerinfo_t *router);
typedef enum {
NO_WEIGHTING, WEIGHT_FOR_EXIT, WEIGHT_FOR_GUARD

19
src/or/policies.c
View File

@ -1039,7 +1039,7 @@ policy_summary_reject(smartlist_t *summary,
{
int i = policy_summary_split(summary, prt_min, prt_max);
/* XXX: ipv4 specific */
int count = (1 << (32-maskbits));
uint64_t count = (U64_LITERAL(1) << (32-maskbits));
while (i < smartlist_len(summary) &&
AT(i)->prt_max <= prt_max) {
AT(i)->reject_count += count;
@ -1160,7 +1160,21 @@ policy_summarize(smartlist_t *policy)
accepts_str = smartlist_join_strings(accepts, ",", 0, &accepts_len);
rejects_str = smartlist_join_strings(rejects, ",", 0, &rejects_len);
if (rejects_len < accepts_len) {
if (rejects_len > MAX_EXITPOLICY_SUMMARY_LEN &&
accepts_len > MAX_EXITPOLICY_SUMMARY_LEN) {
char *c;
shorter_str = accepts_str;
prefix = "accept";
c = shorter_str + (MAX_EXITPOLICY_SUMMARY_LEN-strlen(prefix)-1);
while (*c != ',' && c >= shorter_str)
c--;
tor_assert(c >= shorter_str);
tor_assert(*c == ',');
*c = '\0';
shorter_len = strlen(shorter_str);
} else if (rejects_len < accepts_len) {
shorter_str = rejects_str;
shorter_len = rejects_len;
prefix = "reject";
@ -1171,6 +1185,7 @@ policy_summarize(smartlist_t *policy)
}
final_size = strlen(prefix)+1+shorter_len+1;
tor_assert(final_size <= MAX_EXITPOLICY_SUMMARY_LEN+1);
result = malloc(final_size);
tor_snprintf(result, final_size, "%s %s", prefix, shorter_str);

43
src/or/test.c
View File

@ -3355,10 +3355,13 @@ test_policy_summary_helper(const char *policy_str,
static void
test_policies(void)
{
int i;
smartlist_t *policy, *policy2;
addr_policy_t *p;
tor_addr_t tar;
config_line_t line;
smartlist_t *sm;
char *policy_str;
policy = smartlist_create();
@ -3458,6 +3461,46 @@ test_policies(void)
"accept *:65535,"
"reject *:*",
"accept 1,3,65535");
/* holes */
test_policy_summary_helper("accept *:1,"
"accept *:3,"
"accept *:5,"
"accept *:7,"
"reject *:*",
"accept 1,3,5,7");
test_policy_summary_helper("reject *:1,"
"reject *:3,"
"reject *:5,"
"reject *:7,"
"accept *:*",
"reject 1,3,5,7");
/* truncation ports */
sm = smartlist_create();
for (i=1; i<2000; i+=2) {
char buf[POLICY_BUF_LEN];
tor_snprintf(buf, sizeof(buf), "reject *:%d", i);
smartlist_add(sm, tor_strdup(buf));
}
smartlist_add(sm, tor_strdup("accept *:*"));
policy_str = smartlist_join_strings(sm, ",", 0, NULL);
test_policy_summary_helper( policy_str,
"accept 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,"
"46,48,50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,"
"92,94,96,98,100,102,104,106,108,110,112,114,116,118,120,122,124,126,128,"
"130,132,134,136,138,140,142,144,146,148,150,152,154,156,158,160,162,164,"
"166,168,170,172,174,176,178,180,182,184,186,188,190,192,194,196,198,200,"
"202,204,206,208,210,212,214,216,218,220,222,224,226,228,230,232,234,236,"
"238,240,242,244,246,248,250,252,254,256,258,260,262,264,266,268,270,272,"
"274,276,278,280,282,284,286,288,290,292,294,296,298,300,302,304,306,308,"
"310,312,314,316,318,320,322,324,326,328,330,332,334,336,338,340,342,344,"
"346,348,350,352,354,356,358,360,362,364,366,368,370,372,374,376,378,380,"
"382,384,386,388,390,392,394,396,398,400,402,404,406,408,410,412,414,416,"
"418,420,422,424,426,428,430,432,434,436,438,440,442,444,446,448,450,452,"
"454,456,458,460,462,464,466,468,470,472,474,476,478,480,482,484,486,488,"
"490,492,494,496,498,500,502,504,506,508,510,512,514,516,518,520,522");
tor_free(policy_str);
SMARTLIST_FOREACH(sm, char *, s, tor_free(s));
smartlist_clear(sm);
}
static void