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| author | Daniel Stenberg <daniel@haxx.se> | 2021-01-19 08:23:52 +0100 |
|---|---|---|
| committer | Daniel Stenberg <daniel@haxx.se> | 2021-01-20 08:51:01 +0100 |
| commit | 942cf12c2f73c4bb13858acc9101b1d644bf7c50 (patch) | |
| tree | 0478f4aa93712d7b06b39da268aaae9ec102f312 /lib/share.c | |
| parent | 13bc1ea9bcef34c4beb384549e4be64e341426db (diff) | |
| download | curl-942cf12c2f73c4bb13858acc9101b1d644bf7c50.tar.gz | |
urldata: make magic be the first struct field
By making the `magic` identifier the same size and at the same place
within the structs (easy, multi, share), libcurl will be able to more
reliably detect and safely error out if an application passes in the
wrong handle to APIs. Easier to detect and less likely to cause crashes
if done.
Such mixups can't be detected at compile-time due to them being
typedefed void pointers - unless `CURL_STRICTER` is defined.
Closes #6484
Diffstat (limited to 'lib/share.c')
| -rw-r--r-- | lib/share.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/lib/share.c b/lib/share.c index 5ce983033..4f1804dbd 100644 --- a/lib/share.c +++ b/lib/share.c @@ -5,7 +5,7 @@ * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * - * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al. + * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms @@ -37,6 +37,7 @@ curl_share_init(void) { struct Curl_share *share = calloc(1, sizeof(struct Curl_share)); if(share) { + share->magic = CURL_GOOD_SHARE; share->specifier |= (1<<CURL_LOCK_DATA_SHARE); if(Curl_mk_dnscache(&share->hostcache)) { @@ -59,6 +60,9 @@ curl_share_setopt(struct Curl_share *share, CURLSHoption option, ...) void *ptr; CURLSHcode res = CURLSHE_OK; + if(!GOOD_SHARE_HANDLE(share)) + return CURLSHE_INVALID; + if(share->dirty) /* don't allow setting options while one or more handles are already using this share */ @@ -184,7 +188,7 @@ curl_share_setopt(struct Curl_share *share, CURLSHoption option, ...) CURLSHcode curl_share_cleanup(struct Curl_share *share) { - if(share == NULL) + if(!GOOD_SHARE_HANDLE(share)) return CURLSHE_INVALID; if(share->lockfunc) @@ -218,6 +222,7 @@ curl_share_cleanup(struct Curl_share *share) if(share->unlockfunc) share->unlockfunc(NULL, CURL_LOCK_DATA_SHARE, share->clientdata); + share->magic = 0; free(share); return CURLSHE_OK; |