Mercurial > hg > nginx
view src/core/ngx_parse.c @ 4576:876e6b0814a5
Fixed signed integer overflows in timer code (ticket #145).
Integer overflow is undefined behaviour in C and this indeed caused
problems on Solaris/SPARC (at least in some cases). Fix is to
subtract unsigned integers instead, and then cast result to a signed
one, which is implementation-defined behaviour and used to work.
Strictly speaking, we should compare (unsigned) result with the maximum
value of the corresponding signed integer type instead, this will be
defined behaviour. This will require much more changes though, and
considered to be overkill for now.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 06 Apr 2012 23:46:09 +0000 |
parents | d620f497c50f |
children | 15a15f6ae3a2 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> ssize_t ngx_parse_size(ngx_str_t *line) { u_char unit; size_t len; ssize_t size; ngx_int_t scale; len = line->len; unit = line->data[len - 1]; switch (unit) { case 'K': case 'k': len--; scale = 1024; break; case 'M': case 'm': len--; scale = 1024 * 1024; break; default: scale = 1; } size = ngx_atosz(line->data, len); if (size == NGX_ERROR) { return NGX_ERROR; } size *= scale; return size; } off_t ngx_parse_offset(ngx_str_t *line) { u_char unit; off_t offset; size_t len; ngx_int_t scale; len = line->len; unit = line->data[len - 1]; switch (unit) { case 'K': case 'k': len--; scale = 1024; break; case 'M': case 'm': len--; scale = 1024 * 1024; break; case 'G': case 'g': len--; scale = 1024 * 1024 * 1024; break; default: scale = 1; } offset = ngx_atoof(line->data, len); if (offset == NGX_ERROR) { return NGX_ERROR; } offset *= scale; return offset; } ngx_int_t ngx_parse_time(ngx_str_t *line, ngx_uint_t is_sec) { u_char *p, *last; ngx_int_t value, total, scale; ngx_uint_t max, valid; enum { st_start = 0, st_year, st_month, st_week, st_day, st_hour, st_min, st_sec, st_msec, st_last } step; valid = 0; value = 0; total = 0; step = is_sec ? st_start : st_month; scale = is_sec ? 1 : 1000; p = line->data; last = p + line->len; while (p < last) { if (*p >= '0' && *p <= '9') { value = value * 10 + (*p++ - '0'); valid = 1; continue; } switch (*p++) { case 'y': if (step > st_start) { return NGX_ERROR; } step = st_year; max = NGX_MAX_INT32_VALUE / (60 * 60 * 24 * 365); scale = 60 * 60 * 24 * 365; break; case 'M': if (step >= st_month) { return NGX_ERROR; } step = st_month; max = NGX_MAX_INT32_VALUE / (60 * 60 * 24 * 30); scale = 60 * 60 * 24 * 30; break; case 'w': if (step >= st_week) { return NGX_ERROR; } step = st_week; max = NGX_MAX_INT32_VALUE / (60 * 60 * 24 * 7); scale = 60 * 60 * 24 * 7; break; case 'd': if (step >= st_day) { return NGX_ERROR; } step = st_day; max = NGX_MAX_INT32_VALUE / (60 * 60 * 24); scale = 60 * 60 * 24; break; case 'h': if (step >= st_hour) { return NGX_ERROR; } step = st_hour; max = NGX_MAX_INT32_VALUE / (60 * 60); scale = 60 * 60; break; case 'm': if (*p == 's') { if (is_sec || step >= st_msec) { return NGX_ERROR; } p++; step = st_msec; max = NGX_MAX_INT32_VALUE; scale = 1; break; } if (step >= st_min) { return NGX_ERROR; } step = st_min; max = NGX_MAX_INT32_VALUE / 60; scale = 60; break; case 's': if (step >= st_sec) { return NGX_ERROR; } step = st_sec; max = NGX_MAX_INT32_VALUE; scale = 1; break; case ' ': if (step >= st_sec) { return NGX_ERROR; } step = st_last; max = NGX_MAX_INT32_VALUE; scale = 1; break; default: return NGX_ERROR; } if (step != st_msec && !is_sec) { scale *= 1000; max /= 1000; } if ((ngx_uint_t) value > max) { return NGX_ERROR; } total += value * scale; if ((ngx_uint_t) total > NGX_MAX_INT32_VALUE) { return NGX_ERROR; } value = 0; scale = is_sec ? 1 : 1000; while (p < last && *p == ' ') { p++; } } if (valid) { return total + value * scale; } return NGX_ERROR; }