[trafficserver] branch 7.1.x updated: This improves on #3008, making the code clearer

[eze]

This is an automated email from the ASF dual-hosted git repository.

eze pushed a commit to branch 7.1.x
in repository https://gitbox.apache.org/repos/asf/trafficserver.git


The following commit(s) were added to refs/heads/7.1.x by this push:
     new 018ff84  This improves on #3008, making the code clearer
018ff84 is described below

commit 018ff84893c6bfec86bc5b548524cc51a824b1b4
Author: Leif Hedstrom <zw...@apache.org>
AuthorDate: Wed Jan 9 09:46:41 2019 -0700

    This improves on #3008, making the code clearer
    
    (cherry picked from commit 571d11ecf49c410470e2efbc1eca469618629084)
---
 proxy/http/HttpSM.cc | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/proxy/http/HttpSM.cc b/proxy/http/HttpSM.cc
index 3e86697..962c5bb 100644
--- a/proxy/http/HttpSM.cc
+++ b/proxy/http/HttpSM.cc
@@ -4259,8 +4259,6 @@ HttpSM::parse_range_and_compare(MIMEField *field, int64_t 
content_length)
   const char *s, *e, *tmp;
   RangeRecord *ranges = nullptr;
   int64_t start, end;
-  int64_t cutoff = INT64_MAX / 10;
-  int64_t cutlim = INT64_MAX % 10;
 
   ink_assert(field != nullptr && t_state.range_setup == 
HttpTransact::RANGE_NONE && t_state.ranges == nullptr);
 
@@ -4319,11 +4317,13 @@ HttpSM::parse_range_and_compare(MIMEField *field, 
int64_t content_length)
       for (start = 0; s < e && *s >= '0' && *s <= '9'; ++s) {
         // check the int64 overflow in case of high gcc with O3 option
         // thinking the start is always positive
-        if (start >= cutoff && (start > cutoff || *s - '0' > cutlim)) {
+        int64_t new_start = start * 10 + (*s - '0');
+
+        if (new_start < start) { // Overflow
           t_state.range_setup = HttpTransact::RANGE_NONE;
           goto Lfaild;
         }
-        start = start * 10 + (*s - '0');
+        start = new_start;
       }
       // skip last white spaces
       for (; s < e && ParseRules::is_ws(*s); ++s) {
@@ -4357,11 +4357,13 @@ HttpSM::parse_range_and_compare(MIMEField *field, 
int64_t content_length)
       for (end = 0; s < e && *s >= '0' && *s <= '9'; ++s) {
         // check the int64 overflow in case of high gcc with O3 option
         // thinking the start is always positive
-        if (end >= cutoff && (end > cutoff || *s - '0' > cutlim)) {
+        int64_t new_end = end * 10 + (*s - '0');
+
+        if (new_end < end) { // Overflow
           t_state.range_setup = HttpTransact::RANGE_NONE;
           goto Lfaild;
         }
-        end = end * 10 + (*s - '0');
+        end = new_end;
       }
       // skip last white spaces
       for (; s < e && ParseRules::is_ws(*s); ++s) {