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author | teor <teor2345@gmail.com> | 2015-01-10 17:20:06 +1100 |
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committer | teor <teor2345@gmail.com> | 2015-01-10 17:20:06 +1100 |
commit | f8ffb57bc4430ff9bbd7560eecdda4284b2799ba (patch) | |
tree | 7b73b0bf39d756c31bb62dbcd3c239864a6a46c8 /src/common/util.c | |
parent | debd7862bb6d641c13fe4ee019da633c683d740e (diff) | |
parent | 33df3e37ffecfed309a1a0f210a96620c0ebb837 (diff) | |
download | tor-f8ffb57bc4430ff9bbd7560eecdda4284b2799ba.tar.gz tor-f8ffb57bc4430ff9bbd7560eecdda4284b2799ba.zip |
Merge branch 'master' of https://git.torproject.org/tor into bug13111-empty-key-files-fn-empty
Conflicts:
src/or/connection_edge.c
Merged in favour of origin.
Diffstat (limited to 'src/common/util.c')
-rw-r--r-- | src/common/util.c | 73 |
1 files changed, 67 insertions, 6 deletions
diff --git a/src/common/util.c b/src/common/util.c index 2f01a83974..5e9dd18f02 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -1,6 +1,6 @@ /* Copyright (c) 2003, Roger Dingledine * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2014, The Tor Project, Inc. */ + * Copyright (c) 2007-2015, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -513,6 +513,51 @@ round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor) return number; } +/** Return the lowest x in [INT64_MIN, INT64_MAX] such that x is at least + * <b>number</b>, and x modulo <b>divisor</b> == 0. */ +int64_t +round_int64_to_next_multiple_of(int64_t number, int64_t divisor) +{ + tor_assert(divisor > 0); + if (number >= 0 && INT64_MAX - divisor + 1 >= number) + number += divisor - 1; + number -= number % divisor; + return number; +} + +/** Transform a random value <b>p</b> from the uniform distribution in + * [0.0, 1.0[ into a Laplace distributed value with location parameter + * <b>mu</b> and scale parameter <b>b</b> in [-Inf, Inf[. */ +double +sample_laplace_distribution(double mu, double b, double p) +{ + tor_assert(p >= 0.0 && p < 1.0); + /* This is the "inverse cumulative distribution function" from: + * http://en.wikipedia.org/wiki/Laplace_distribution */ + return mu - b * (p > 0.5 ? 1.0 : -1.0) + * tor_mathlog(1.0 - 2.0 * fabs(p - 0.5)); +} + +/** Add random noise between INT64_MIN and INT64_MAX coming from a + * Laplace distribution with mu = 0 and b = <b>delta_f</b>/<b>epsilon</b> + * to <b>signal</b> based on the provided <b>random</b> value in + * [0.0, 1.0[. */ +int64_t +add_laplace_noise(int64_t signal, double random, double delta_f, + double epsilon) +{ + /* cast to int64_t intended */ + int64_t noise = sample_laplace_distribution( + 0.0, /* just add noise, no further signal */ + delta_f / epsilon, random); + if (noise > 0 && INT64_MAX - noise < signal) + return INT64_MAX; + else if (noise < 0 && INT64_MIN - noise > signal) + return INT64_MIN; + else + return signal + noise; +} + /** Return the number of bits set in <b>v</b>. */ int n_bits_set_u8(uint8_t v) @@ -1223,6 +1268,9 @@ base16_decode(char *dest, size_t destlen, const char *src, size_t srclen) return -1; if (destlen < srclen/2 || destlen > SIZE_T_CEILING) return -1; + + memset(dest, 0, destlen); + end = src+srclen; while (src<end) { v1 = hex_decode_digit_(*src); @@ -1656,15 +1704,18 @@ format_iso_time_nospace_usec(char *buf, const struct timeval *tv) /** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>, * parse it and store its value in *<b>t</b>. Return 0 on success, -1 on - * failure. Ignore extraneous stuff in <b>cp</b> separated by whitespace from - * the end of the time string. */ + * failure. Ignore extraneous stuff in <b>cp</b> after the end of the time + * string, unless <b>strict</b> is set. */ int -parse_iso_time(const char *cp, time_t *t) +parse_iso_time_(const char *cp, time_t *t, int strict) { struct tm st_tm; unsigned int year=0, month=0, day=0, hour=0, minute=0, second=0; - if (tor_sscanf(cp, "%u-%2u-%2u %2u:%2u:%2u", &year, &month, - &day, &hour, &minute, &second) < 6) { + int n_fields; + char extra_char; + n_fields = tor_sscanf(cp, "%u-%2u-%2u %2u:%2u:%2u%c", &year, &month, + &day, &hour, &minute, &second, &extra_char); + if (strict ? (n_fields != 6) : (n_fields < 6)) { char *esc = esc_for_log(cp); log_warn(LD_GENERAL, "ISO time %s was unparseable", esc); tor_free(esc); @@ -1693,6 +1744,16 @@ parse_iso_time(const char *cp, time_t *t) return tor_timegm(&st_tm, t); } +/** Given an ISO-formatted UTC time value (after the epoch) in <b>cp</b>, + * parse it and store its value in *<b>t</b>. Return 0 on success, -1 on + * failure. Reject the string if any characters are present after the time. + */ +int +parse_iso_time(const char *cp, time_t *t) +{ + return parse_iso_time_(cp, t, 1); +} + /** Given a <b>date</b> in one of the three formats allowed by HTTP (ugh), * parse it into <b>tm</b>. Return 0 on success, negative on failure. */ int |