commit a0fad3981e9d072188c6ba19f25bdd78962330d8 Author: Nick Mathewson nickm@torproject.org Date: Mon Dec 17 09:03:04 2018 -0500

Replace use of strcmp_len() with new mem_eq_token().

The strcmp_len() function was somewhat misconceived, since we're only using it to test whether a length+extent string is equal to a NUL-terminated string or not. By simplifying it and making it inlined, we should be able to make it a little faster.

(It *does* show up in profiles.)

Closes ticket 28856. --- src/feature/dirparse/parsecommon.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/src/feature/dirparse/parsecommon.c b/src/feature/dirparse/parsecommon.c index e00af0eea..a69957e74 100644 --- a/src/feature/dirparse/parsecommon.c +++ b/src/feature/dirparse/parsecommon.c @@ -15,6 +15,7 @@ #include "lib/string/printf.h" #include "lib/memarea/memarea.h" #include "lib/crypt_ops/crypto_rsa.h" +#include "lib/ctime/di_ops.h"

#include <string.h>

@@ -251,6 +252,16 @@ token_check_object(memarea_t *area, const char *kwd, return tok; }

+/** Return true iff the <b>memlen</b>-byte chunk of memory at + * <b>memlen</b> is the same length as <b>token</b>, and their + * contents are equal. */ +static bool +mem_eq_token(const void *mem, size_t memlen, const char *token) +{ + size_t len = strlen(token); + return memlen == len && fast_memeq(mem, token, len); +} + /** Helper function: read the next token from *s, advance *s to the end of the * token, and return the parsed token. Parse *<b>s</b> according to the list * of tokens in <b>table</b>. @@ -290,7 +301,7 @@ get_next_token(memarea_t *area,

next = find_whitespace_eos(*s, eol);

- if (!strcmp_len(*s, "opt", next-*s)) { + if (mem_eq_token(*s, next-*s, "opt")) { /* Skip past an "opt" at the start of the line. */ *s = eat_whitespace_eos_no_nl(next, eol); next = find_whitespace_eos(*s, eol); @@ -301,7 +312,7 @@ get_next_token(memarea_t *area, /* Search the table for the appropriate entry. (I tried a binary search * instead, but it wasn't any faster.) */ for (i = 0; table[i].t ; ++i) { - if (!strcmp_len(*s, table[i].t, next-*s)) { + if (mem_eq_token(*s, next-*s, table[i].t)) { /* We've found the keyword. */ kwd = table[i].t; tok->tp = table[i].v; @@ -354,7 +365,7 @@ get_next_token(memarea_t *area,

obstart = *s; /* Set obstart to start of object spec */ if (eol - *s <= 16 || memchr(*s+11,'\0',eol-*s-16) || /* no short lines, */ - strcmp_len(eol-5, "-----", 5) || /* nuls or invalid endings */ + !mem_eq_token(eol-5, 5, "-----") || /* nuls or invalid endings */ (eol-*s) > MAX_UNPARSED_OBJECT_SIZE) { /* name too long */ RET_ERR("Malformed object: bad begin line"); } @@ -373,8 +384,8 @@ get_next_token(memarea_t *area, eol = eos; /* Validate the ending tag, which should be 9 + NAME + 5 + eol */ if ((size_t)(eol-next) != 9+obname_len+5 || - strcmp_len(next+9, tok->object_type, obname_len) || - strcmp_len(eol-5, "-----", 5)) { + !mem_eq_token(next+9, obname_len, tok->object_type) || + !mem_eq_token(eol-5, 5, "-----")) { tor_snprintf(ebuf, sizeof(ebuf), "Malformed object: mismatched end tag %s", tok->object_type); ebuf[sizeof(ebuf)-1] = '\0';