@matheusbsbs / matheus-bagliano / commits / b0e3e2d06b

http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION

The IOCTLFUNCTION option has been deprecated, and generates a compiler warning in recent versions of curl. We can switch to using SEEKFUNCTION instead. It was added in 2008 via curl 7.18.0; our INSTALL file already indicates we require at least curl 7.19.4. But there's one catch: curl says we should use CURL_SEEKFUNC_{OK,FAIL}, and those didn't arrive until 7.19.5. One workaround would be to use a bare 0/1 here (or define our own macros). But let's just bump the minimum required version to 7.19.5. That version is only a minor version bump from our existing requirement, and is only a 2 month time bump for versions that are almost 13 years old. So it's not likely that anybody cares about the distinction. Switching means we have to rewrite the ioctl functions into seek functions. In some ways they are simpler (seeking is the only operation), but in some ways more complex (the ioctl allowed only a full rewind, but now we can seek to arbitrary offsets). Curl will only ever use SEEK_SET (per their documentation), so I didn't bother implementing anything else, since it would naturally be completely untested. This seems unlikely to change, but I added an assertion just in case. Likewise, I doubt curl will ever try to seek outside of the buffer sizes we've told it, but I erred on the defensive side here, rather than do an out-of-bounds read. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Jeff King committed Jan 16, 2023 at 22:04 UTC b0e3e2d06ba3b71079d7b9b6402a0f410180c09b

5 files changed +36 -36

INSTALL

@@ -145,6 +145,10 @@ Issues of note:

145 patches into an IMAP mailbox, you do not have to have them

146 (use NO_CURL).

147

148 + Git requires version "7.19.5" or later of "libcurl" to build

149 + without NO_CURL. This version requirement may be bumped in

150 + the future.

151 +

152 - "expat" library; git-http-push uses it for remote lock

153 management over DAV. Similar to "curl" above, this is optional

154 (with NO_EXPAT).

http-push.c

+3 -3

@@ -203,9 +203,9 @@ static void curl_setup_http(CURL *curl, const char *url,

203 curl_easy_setopt(curl, CURLOPT_INFILE, buffer);

204 curl_easy_setopt(curl, CURLOPT_INFILESIZE, buffer->buf.len);

205 curl_easy_setopt(curl, CURLOPT_READFUNCTION, fread_buffer);

206 -#ifndef NO_CURL_IOCTL

207 - curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_buffer);

208 - curl_easy_setopt(curl, CURLOPT_IOCTLDATA, buffer);

206 +#ifndef NO_CURL_SEEK

207 + curl_easy_setopt(curl, CURLOPT_SEEKFUNCTION, seek_buffer);

208 + curl_easy_setopt(curl, CURLOPT_SEEKDATA, buffer);

209 #endif

210 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_fn);

211 curl_easy_setopt(curl, CURLOPT_NOBODY, 0);

http.c

+10 -12

@@ -186,22 +186,20 @@ size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)

186 return size / eltsize;

187 }

188

189 -#ifndef NO_CURL_IOCTL

190 -curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)

189 +#ifndef NO_CURL_SEEK

190 +int seek_buffer(void *clientp, curl_off_t offset, int origin)

191 {

192 struct buffer *buffer = clientp;

193

194 - switch (cmd) {

195 - case CURLIOCMD_NOP:

196 - return CURLIOE_OK;

197 -

198 - case CURLIOCMD_RESTARTREAD:

199 - buffer->posn = 0;

200 - return CURLIOE_OK;

201 -

202 - default:

203 - return CURLIOE_UNKNOWNCMD;

194 + if (origin != SEEK_SET)

195 + BUG("seek_buffer only handles SEEK_SET");

196 + if (offset < 0 || offset >= buffer->buf.len) {

197 + error("curl seek would be outside of buffer");

198 + return CURL_SEEKFUNC_FAIL;

199 }

200 +

201 + buffer->posn = offset;

202 + return CURL_SEEKFUNC_OK;

203 }

204 #endif

205

http.h

+4 -4

@@ -41,8 +41,8 @@

41 #define CURLE_HTTP_RETURNED_ERROR CURLE_HTTP_NOT_FOUND

42 #endif

44 -#if LIBCURL_VERSION_NUM < 0x070c03

45 -#define NO_CURL_IOCTL

44 +#if LIBCURL_VERSION_NUM < 0x071200

45 +#define NO_CURL_SEEK

46 #endif

48 /*

@@ -82,8 +82,8 @@ struct buffer {

82 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);

83 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);

84 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);

85 -#ifndef NO_CURL_IOCTL

86 -curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);

85 +#ifndef NO_CURL_SEEK

86 +int seek_buffer(void *clientp, curl_off_t offset, int origin);

87 #endif

89 /* Slot lifecycle functions */

remote-curl.c

+15 -17

@@ -707,26 +707,24 @@ static size_t rpc_out(void *ptr, size_t eltsize,

707 return avail;

708 }

709

710 -#ifndef NO_CURL_IOCTL

711 -static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)

710 +#ifndef NO_CURL_SEEK

711 +static int rpc_seek(void *clientp, curl_off_t offset, int origin)

712 {

713 struct rpc_state *rpc = clientp;

714

715 - switch (cmd) {

716 - case CURLIOCMD_NOP:

717 - return CURLIOE_OK;

715 + if (origin != SEEK_SET)

716 + BUG("rpc_seek only handles SEEK_SET, not %d", origin);

717

719 - case CURLIOCMD_RESTARTREAD:

720 - if (rpc->initial_buffer) {

721 - rpc->pos = 0;

722 - return CURLIOE_OK;

718 + if (rpc->initial_buffer) {

719 + if (offset < 0 || offset > rpc->len) {

720 + error("curl seek would be outside of rpc buffer");

721 + return CURL_SEEKFUNC_FAIL;

722 }

724 - error(_("unable to rewind rpc post data - try increasing http.postBuffer"));

725 - return CURLIOE_FAILRESTART;

726 -

727 - default:

728 - return CURLIOE_UNKNOWNCMD;

723 + rpc->pos = offset;

724 + return CURL_SEEKFUNC_OK;

725 }

726 + error(_("unable to rewind rpc post data - try increasing http.postBuffer"));

727 + return CURL_SEEKFUNC_FAIL;

728 }

729 #endif

730

@@ -947,9 +945,9 @@ retry:

945 rpc->initial_buffer = 1;

946 curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, rpc_out);

947 curl_easy_setopt(slot->curl, CURLOPT_INFILE, rpc);

950 -#ifndef NO_CURL_IOCTL

951 - curl_easy_setopt(slot->curl, CURLOPT_IOCTLFUNCTION, rpc_ioctl);

952 - curl_easy_setopt(slot->curl, CURLOPT_IOCTLDATA, rpc);

948 +#ifndef NO_CURL_SEEK

949 + curl_easy_setopt(slot->curl, CURLOPT_SEEKFUNCTION, rpc_seek);

950 + curl_easy_setopt(slot->curl, CURLOPT_SEEKDATA, rpc);

951 #endif

952 if (options.verbosity > 1) {

953 fprintf(stderr, "POST %s (chunked)\n", rpc->service_name);