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Diffstat (limited to 'src/feature/stats/bwhist.c')
| -rw-r--r-- | src/feature/stats/bwhist.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/src/feature/stats/bwhist.c b/src/feature/stats/bwhist.c new file mode 100644 index 0000000000..7cbc5f60a6 --- /dev/null +++ b/src/feature/stats/bwhist.c @@ -0,0 +1,548 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * @file bwhist.c + * @brief Tracking for relay bandwidth history + * + * This module handles bandwidth usage history, used by relays to + * self-report how much bandwidth they've used for different + * purposes over last day or so, in order to generate the + * {dirreq-,}{read,write}-history lines in that they publish. + **/ + +#define BWHIST_PRIVATE +#include "orconfig.h" +#include "core/or/or.h" +#include "feature/stats/bwhist.h" + +#include "app/config/config.h" +#include "app/config/statefile.h" +#include "feature/relay/routermode.h" + +#include "feature/stats/bw_array_st.h" +#include "app/config/or_state_st.h" +#include "app/config/or_options_st.h" + +/** Shift the current period of b forward by one. */ +STATIC void +commit_max(bw_array_t *b) +{ + /* Store total from current period. */ + b->totals[b->next_max_idx] = b->total_in_period; + /* Store maximum from current period. */ + b->maxima[b->next_max_idx++] = b->max_total; + /* Advance next_period and next_max_idx */ + b->next_period += NUM_SECS_BW_SUM_INTERVAL; + if (b->next_max_idx == NUM_TOTALS) + b->next_max_idx = 0; + if (b->num_maxes_set < NUM_TOTALS) + ++b->num_maxes_set; + /* Reset max_total. */ + b->max_total = 0; + /* Reset total_in_period. */ + b->total_in_period = 0; +} + +/** Shift the current observation time of <b>b</b> forward by one second. */ +STATIC void +advance_obs(bw_array_t *b) +{ + int nextidx; + uint64_t total; + + /* Calculate the total bandwidth for the last NUM_SECS_ROLLING_MEASURE + * seconds; adjust max_total as needed.*/ + total = b->total_obs + b->obs[b->cur_obs_idx]; + if (total > b->max_total) + b->max_total = total; + + nextidx = b->cur_obs_idx+1; + if (nextidx == NUM_SECS_ROLLING_MEASURE) + nextidx = 0; + + b->total_obs = total - b->obs[nextidx]; + b->obs[nextidx]=0; + b->cur_obs_idx = nextidx; + + if (++b->cur_obs_time >= b->next_period) + commit_max(b); +} + +/** Add <b>n</b> bytes to the number of bytes in <b>b</b> for second + * <b>when</b>. */ +STATIC void +add_obs(bw_array_t *b, time_t when, uint64_t n) +{ + if (when < b->cur_obs_time) + return; /* Don't record data in the past. */ + + /* If we're currently adding observations for an earlier second than + * 'when', advance b->cur_obs_time and b->cur_obs_idx by an + * appropriate number of seconds, and do all the other housekeeping. */ + while (when > b->cur_obs_time) { + /* Doing this one second at a time is potentially inefficient, if we start + with a state file that is very old. Fortunately, it doesn't seem to + show up in profiles, so we can just ignore it for now. */ + advance_obs(b); + } + + b->obs[b->cur_obs_idx] += n; + b->total_in_period += n; +} + +/** Allocate, initialize, and return a new bw_array. */ +STATIC bw_array_t * +bw_array_new(void) +{ + bw_array_t *b; + time_t start; + b = tor_malloc_zero(sizeof(bw_array_t)); + start = time(NULL); + b->cur_obs_time = start; + b->next_period = start + NUM_SECS_BW_SUM_INTERVAL; + return b; +} + +/** Free storage held by bandwidth array <b>b</b>. */ +STATIC void +bw_array_free_(bw_array_t *b) +{ + if (!b) { + return; + } + + tor_free(b); +} + +/** Recent history of bandwidth observations for (all) read operations. */ +static bw_array_t *read_array = NULL; +/** Recent history of bandwidth observations for IPv6 read operations. */ +static bw_array_t *read_array_ipv6 = NULL; +/** Recent history of bandwidth observations for (all) write operations. */ +STATIC bw_array_t *write_array = NULL; +/** Recent history of bandwidth observations for IPv6 write operations. */ +static bw_array_t *write_array_ipv6 = NULL; +/** Recent history of bandwidth observations for read operations for the + directory protocol. */ +static bw_array_t *dir_read_array = NULL; +/** Recent history of bandwidth observations for write operations for the + directory protocol. */ +static bw_array_t *dir_write_array = NULL; + +/** Set up structures for bandwidth history, clearing them if they already + * exist. */ +void +bwhist_init(void) +{ + bw_array_free(read_array); + bw_array_free(read_array_ipv6); + bw_array_free(write_array); + bw_array_free(write_array_ipv6); + bw_array_free(dir_read_array); + bw_array_free(dir_write_array); + + read_array = bw_array_new(); + read_array_ipv6 = bw_array_new(); + write_array = bw_array_new(); + write_array_ipv6 = bw_array_new(); + dir_read_array = bw_array_new(); + dir_write_array = bw_array_new(); +} + +/** Remember that we read <b>num_bytes</b> bytes in second <b>when</b>. + * + * Add num_bytes to the current running total for <b>when</b>. + * + * <b>when</b> can go back to time, but it's safe to ignore calls + * earlier than the latest <b>when</b> you've heard of. + */ +void +bwhist_note_bytes_written(uint64_t num_bytes, time_t when, bool ipv6) +{ +/* Maybe a circular array for recent seconds, and step to a new point + * every time a new second shows up. Or simpler is to just to have + * a normal array and push down each item every second; it's short. + */ +/* When a new second has rolled over, compute the sum of the bytes we've + * seen over when-1 to when-1-NUM_SECS_ROLLING_MEASURE, and stick it + * somewhere. See bwhist_bandwidth_assess() below. + */ + add_obs(write_array, when, num_bytes); + if (ipv6) + add_obs(write_array_ipv6, when, num_bytes); +} + +/** Remember that we wrote <b>num_bytes</b> bytes in second <b>when</b>. + * (like bwhist_note_bytes_written() above) + */ +void +bwhist_note_bytes_read(uint64_t num_bytes, time_t when, bool ipv6) +{ +/* if we're smart, we can make this func and the one above share code */ + add_obs(read_array, when, num_bytes); + if (ipv6) + add_obs(read_array_ipv6, when, num_bytes); +} + +/** Remember that we wrote <b>num_bytes</b> directory bytes in second + * <b>when</b>. (like bwhist_note_bytes_written() above) + */ +void +bwhist_note_dir_bytes_written(uint64_t num_bytes, time_t when) +{ + add_obs(dir_write_array, when, num_bytes); +} + +/** Remember that we read <b>num_bytes</b> directory bytes in second + * <b>when</b>. (like bwhist_note_bytes_written() above) + */ +void +bwhist_note_dir_bytes_read(uint64_t num_bytes, time_t when) +{ + add_obs(dir_read_array, when, num_bytes); +} + +/** Helper: Return the largest value in b->maxima. (This is equal to the + * most bandwidth used in any NUM_SECS_ROLLING_MEASURE period for the last + * NUM_SECS_BW_SUM_IS_VALID seconds.) + */ +STATIC uint64_t +find_largest_max(bw_array_t *b) +{ + int i; + uint64_t max; + max=0; + for (i=0; i<NUM_TOTALS; ++i) { + if (b->maxima[i]>max) + max = b->maxima[i]; + } + return max; +} + +/** Find the largest sums in the past NUM_SECS_BW_SUM_IS_VALID (roughly) + * seconds. Find one sum for reading and one for writing. They don't have + * to be at the same time. + * + * Return the smaller of these sums, divided by NUM_SECS_ROLLING_MEASURE. + */ +MOCK_IMPL(int, +bwhist_bandwidth_assess,(void)) +{ + uint64_t w,r; + r = find_largest_max(read_array); + w = find_largest_max(write_array); + if (r>w) + return (int)(((double)w)/NUM_SECS_ROLLING_MEASURE); + else + return (int)(((double)r)/NUM_SECS_ROLLING_MEASURE); +} + +/** Print the bandwidth history of b (either [dir-]read_array or + * [dir-]write_array) into the buffer pointed to by buf. The format is + * simply comma separated numbers, from oldest to newest. + * + * It returns the number of bytes written. + */ +STATIC size_t +bwhist_fill_bandwidth_history(char *buf, size_t len, const bw_array_t *b) +{ + char *cp = buf; + int i, n; + const or_options_t *options = get_options(); + uint64_t cutoff; + + if (b->num_maxes_set <= b->next_max_idx) { + /* We haven't been through the circular array yet; time starts at i=0.*/ + i = 0; + } else { + /* We've been around the array at least once. The next i to be + overwritten is the oldest. */ + i = b->next_max_idx; + } + + if (options->RelayBandwidthRate) { + /* We don't want to report that we used more bandwidth than the max we're + * willing to relay; otherwise everybody will know how much traffic + * we used ourself. */ + cutoff = options->RelayBandwidthRate * NUM_SECS_BW_SUM_INTERVAL; + } else { + cutoff = UINT64_MAX; + } + + for (n=0; n<b->num_maxes_set; ++n,++i) { + uint64_t total; + if (i >= NUM_TOTALS) + i -= NUM_TOTALS; + tor_assert(i < NUM_TOTALS); + /* Round the bandwidth used down to the nearest 1k. */ + total = b->totals[i] & ~0x3ff; + if (total > cutoff) + total = cutoff; + + if (n==(b->num_maxes_set-1)) + tor_snprintf(cp, len-(cp-buf), "%"PRIu64, (total)); + else + tor_snprintf(cp, len-(cp-buf), "%"PRIu64",", (total)); + cp += strlen(cp); + } + return cp-buf; +} + +/** Encode a single bandwidth history line into <b>buf</b>. */ +static void +bwhist_get_one_bandwidth_line(buf_t *buf, const char *desc, + const bw_array_t *b) +{ + /* [dirreq-](read|write)-history yyyy-mm-dd HH:MM:SS (n s) n,n,n... */ + /* The n,n,n part above. Largest representation of a uint64_t is 20 chars + * long, plus the comma. */ +#define MAX_HIST_VALUE_LEN (21*NUM_TOTALS) + + char tmp[MAX_HIST_VALUE_LEN]; + char end[ISO_TIME_LEN+1]; + + size_t slen = bwhist_fill_bandwidth_history(tmp, MAX_HIST_VALUE_LEN, b); + /* If we don't have anything to write, skip to the next entry. */ + if (slen == 0) + return; + + format_iso_time(end, b->next_period-NUM_SECS_BW_SUM_INTERVAL); + buf_add_printf(buf, "%s %s (%d s) %s\n", + desc, end, NUM_SECS_BW_SUM_INTERVAL, tmp); +} + +/** Allocate and return lines for representing this server's bandwidth + * history in its descriptor. We publish these lines in our extra-info + * descriptor. + */ +char * +bwhist_get_bandwidth_lines(void) +{ + buf_t *buf = buf_new(); + + bwhist_get_one_bandwidth_line(buf, "write-history", write_array); + bwhist_get_one_bandwidth_line(buf, "read-history", read_array); + bwhist_get_one_bandwidth_line(buf, "ipv6-write-history", write_array_ipv6); + bwhist_get_one_bandwidth_line(buf, "ipv6-read-history", read_array_ipv6); + bwhist_get_one_bandwidth_line(buf, "dirreq-write-history", dir_write_array); + bwhist_get_one_bandwidth_line(buf, "dirreq-read-history", dir_read_array); + + char *result = buf_extract(buf, NULL); + buf_free(buf); + return result; +} + +/** Write a single bw_array_t into the Values, Ends, Interval, and Maximum + * entries of an or_state_t. Done before writing out a new state file. */ +static void +bwhist_update_bwhist_state_section(or_state_t *state, + const bw_array_t *b, + smartlist_t **s_values, + smartlist_t **s_maxima, + time_t *s_begins, + int *s_interval) +{ + int i,j; + uint64_t maxval; + + if (*s_values) { + SMARTLIST_FOREACH(*s_values, char *, val, tor_free(val)); + smartlist_free(*s_values); + } + if (*s_maxima) { + SMARTLIST_FOREACH(*s_maxima, char *, val, tor_free(val)); + smartlist_free(*s_maxima); + } + if (! server_mode(get_options())) { + /* Clients don't need to store bandwidth history persistently; + * force these values to the defaults. */ + /* FFFF we should pull the default out of config.c's state table, + * so we don't have two defaults. */ + if (*s_begins != 0 || *s_interval != 900) { + time_t now = time(NULL); + time_t save_at = get_options()->AvoidDiskWrites ? now+3600 : now+600; + or_state_mark_dirty(state, save_at); + } + *s_begins = 0; + *s_interval = 900; + *s_values = smartlist_new(); + *s_maxima = smartlist_new(); + return; + } + *s_begins = b->next_period; + *s_interval = NUM_SECS_BW_SUM_INTERVAL; + + *s_values = smartlist_new(); + *s_maxima = smartlist_new(); + /* Set i to first position in circular array */ + i = (b->num_maxes_set <= b->next_max_idx) ? 0 : b->next_max_idx; + for (j=0; j < b->num_maxes_set; ++j,++i) { + if (i >= NUM_TOTALS) + i = 0; + smartlist_add_asprintf(*s_values, "%"PRIu64, + (b->totals[i] & ~0x3ff)); + maxval = b->maxima[i] / NUM_SECS_ROLLING_MEASURE; + smartlist_add_asprintf(*s_maxima, "%"PRIu64, + (maxval & ~0x3ff)); + } + smartlist_add_asprintf(*s_values, "%"PRIu64, + (b->total_in_period & ~0x3ff)); + maxval = b->max_total / NUM_SECS_ROLLING_MEASURE; + smartlist_add_asprintf(*s_maxima, "%"PRIu64, + (maxval & ~0x3ff)); +} + +/** Update <b>state</b> with the newest bandwidth history. Done before + * writing out a new state file. */ +void +bwhist_update_state(or_state_t *state) +{ +#define UPDATE(arrname,st) \ + bwhist_update_bwhist_state_section(state,\ + (arrname),\ + &state->BWHistory ## st ## Values, \ + &state->BWHistory ## st ## Maxima, \ + &state->BWHistory ## st ## Ends, \ + &state->BWHistory ## st ## Interval) + + UPDATE(write_array, Write); + UPDATE(read_array, Read); + UPDATE(write_array_ipv6, IPv6Write); + UPDATE(read_array_ipv6, IPv6Read); + UPDATE(dir_write_array, DirWrite); + UPDATE(dir_read_array, DirRead); + + if (server_mode(get_options())) { + or_state_mark_dirty(state, time(NULL)+(2*3600)); + } +#undef UPDATE +} + +/** Load a single bw_array_t from its Values, Ends, Maxima, and Interval + * entries in an or_state_t. Done while reading the state file. */ +static int +bwhist_load_bwhist_state_section(bw_array_t *b, + const smartlist_t *s_values, + const smartlist_t *s_maxima, + const time_t s_begins, + const int s_interval) +{ + time_t now = time(NULL); + int retval = 0; + time_t start; + + uint64_t v, mv; + int i,ok,ok_m = 0; + int have_maxima = s_maxima && s_values && + (smartlist_len(s_values) == smartlist_len(s_maxima)); + + if (s_values && s_begins >= now - NUM_SECS_BW_SUM_INTERVAL*NUM_TOTALS) { + start = s_begins - s_interval*(smartlist_len(s_values)); + if (start > now) + return 0; + b->cur_obs_time = start; + b->next_period = start + NUM_SECS_BW_SUM_INTERVAL; + SMARTLIST_FOREACH_BEGIN(s_values, const char *, cp) { + const char *maxstr = NULL; + v = tor_parse_uint64(cp, 10, 0, UINT64_MAX, &ok, NULL); + if (have_maxima) { + maxstr = smartlist_get(s_maxima, cp_sl_idx); + mv = tor_parse_uint64(maxstr, 10, 0, UINT64_MAX, &ok_m, NULL); + mv *= NUM_SECS_ROLLING_MEASURE; + } else { + /* No maxima known; guess average rate to be conservative. */ + mv = (v / s_interval) * NUM_SECS_ROLLING_MEASURE; + } + if (!ok) { + retval = -1; + log_notice(LD_HIST, "Could not parse value '%s' into a number.'",cp); + } + if (maxstr && !ok_m) { + retval = -1; + log_notice(LD_HIST, "Could not parse maximum '%s' into a number.'", + maxstr); + } + + if (start < now) { + time_t cur_start = start; + time_t actual_interval_len = s_interval; + uint64_t cur_val = 0; + /* Calculate the average per second. This is the best we can do + * because our state file doesn't have per-second resolution. */ + if (start + s_interval > now) + actual_interval_len = now - start; + cur_val = v / actual_interval_len; + /* This is potentially inefficient, but since we don't do it very + * often it should be ok. */ + while (cur_start < start + actual_interval_len) { + add_obs(b, cur_start, cur_val); + ++cur_start; + } + b->max_total = mv; + /* This will result in some fairly choppy history if s_interval + * is not the same as NUM_SECS_BW_SUM_INTERVAL. XXXX */ + start += actual_interval_len; + } + } SMARTLIST_FOREACH_END(cp); + } + + /* Clean up maxima and observed */ + for (i=0; i<NUM_SECS_ROLLING_MEASURE; ++i) { + b->obs[i] = 0; + } + b->total_obs = 0; + + return retval; +} + +/** Set bandwidth history from the state file we just loaded. */ +int +bwhist_load_state(or_state_t *state, char **err) +{ + int all_ok = 1; + + /* Assert they already have been malloced */ + tor_assert(read_array && write_array); + tor_assert(read_array_ipv6 && write_array_ipv6); + tor_assert(dir_read_array && dir_write_array); + +#define LOAD(arrname,st) \ + if (bwhist_load_bwhist_state_section( \ + (arrname), \ + state->BWHistory ## st ## Values, \ + state->BWHistory ## st ## Maxima, \ + state->BWHistory ## st ## Ends, \ + state->BWHistory ## st ## Interval)<0) \ + all_ok = 0 + + LOAD(write_array, Write); + LOAD(read_array, Read); + LOAD(write_array_ipv6, IPv6Write); + LOAD(read_array_ipv6, IPv6Read); + LOAD(dir_write_array, DirWrite); + LOAD(dir_read_array, DirRead); + +#undef LOAD + if (!all_ok) { + *err = tor_strdup("Parsing of bandwidth history values failed"); + /* and create fresh arrays */ + bwhist_init(); + return -1; + } + return 0; +} + +void +bwhist_free_all(void) +{ + bw_array_free(read_array); + bw_array_free(read_array_ipv6); + bw_array_free(write_array); + bw_array_free(write_array_ipv6); + bw_array_free(dir_read_array); + bw_array_free(dir_write_array); +} |