# [PATCH] http.c: use CURLOPT_RANGE for range requests 2 messages from 2015-10-30 to 2015-10-30. Participants: David Turner. Thread: https://gitlist.dev/t/40682 ## David Turner, 2015-10-30 22:41 Subject: [PATCH] http.c: use CURLOPT_RANGE for range requests Message-ID: <1446244888-32610-1-git-send-email-dturner@twopensource.com> URL: https://gitlist.dev/e/1446244888-32610-1-git-send-email-dturner%40twopensource.com ``` A HTTP server is permitted to return a non-range response to a HTTP range request (and Apache httpd in fact does this in some cases). While libcurl knows how to correctly handle this (by skipping bytes before and after the requested range), it only turns on this handling if it is aware that a range request is being made. By manually setting the range header instead of using CURLOPT_RANGE, we were hiding the fact that this was a range request from libcurl. This could cause corruption. Signed-off-by: David Turner --- http.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/http.c b/http.c index 0f924a8..303b388 100644 --- a/http.c +++ b/http.c @@ -1202,8 +1202,9 @@ static int http_request(const char *url, curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite); if (posn > 0) { - strbuf_addf(&buf, "Range: bytes=%ld-", posn); - headers = curl_slist_append(headers, buf.buf); + strbuf_addf(&buf, "%ld-", posn); + curl_easy_setopt(slot->curl, CURLOPT_RANGE, + &buf.buf); strbuf_reset(&buf); } } else -- 2.4.2.691.g714732c-twtrsrc ``` ## David Turner, 2015-10-30 22:43 Subject: Re: [PATCH] http.c: use CURLOPT_RANGE for range requests Message-ID: <1446245006.16007.0.camel@twopensource.com> URL: https://gitlist.dev/e/1446245006.16007.0.camel%40twopensource.com In-Reply-To: <1446244888-32610-1-git-send-email-dturner@twopensource.com> ``` Please disregard this; I noticed I missed a few instances. Will reroll shortly. On Fri, 2015-10-30 at 18:41 -0400, David Turner wrote: > A HTTP server is permitted to return a non-range response to a HTTP > range request (and Apache httpd in fact does this in some cases). > While libcurl knows how to correctly handle this (by skipping bytes > before and after the requested range), it only turns on this handling > if it is aware that a range request is being made. By manually > setting the range header instead of using CURLOPT_RANGE, we were > hiding the fact that this was a range request from libcurl. This > could cause corruption. > > Signed-off-by: David Turner > --- > http.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/http.c b/http.c > index 0f924a8..303b388 100644 > --- a/http.c > +++ b/http.c > @@ -1202,8 +1202,9 @@ static int http_request(const char *url, > curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, > fwrite); > if (posn > 0) { > - strbuf_addf(&buf, "Range: bytes=%ld-", posn); > - headers = curl_slist_append(headers, buf.buf); > + strbuf_addf(&buf, "%ld-", posn); > + curl_easy_setopt(slot->curl, CURLOPT_RANGE, > + &buf.buf); > strbuf_reset(&buf); > } > } else ```