avformat/http,tls: honor http_proxy command line variable for HTTPS

Add the "http_proxy" option and its handling to the "tls" protocol,
pass the option from the "https" protocol.

The "https" protocol already defines the "http_proxy" command line
option, like the "http" protocol does. The "http" protocol properly
honors that command line option in addition to the environment
variable. The "https" protocol doesn't, because the proxy is
evaluated in the underlying "tls" protocol, which doesn't have this
option, and thus only handles the environment variable, which it
has access to.

Fixes #7223.

Signed-off-by: Moritz Barsnick <barsnick@gmx.net>
Signed-off-by: Marton Balint <cus@passwd.hu>

doc/protocols.texi

@@ -1772,6 +1772,10 @@ A file containing the private key for the certificate.
 If enabled, listen for connections on the provided port, and assume
 the server role in the handshake instead of the client role.
 
+@item http_proxy
+The HTTP proxy to tunnel through, e.g. @code{http://example.com:1234}.
+The proxy must support the CONNECT method.
+
 @end table
 
 Example command lines:

libavformat/http.c

@@ -214,6 +214,12 @@ static int http_open_cnx_internal(URLContext *h, AVDictionary **options)
         use_proxy   = 0;
         if (port < 0)
             port = 443;
+        /* pass http_proxy to underlying protocol */
+        if (s->http_proxy) {
+            err = av_dict_set(options, "http_proxy", s->http_proxy, 0);
+            if (err < 0)
+                return err;
+        }
     }
     if (port < 0)
         port = 80;

libavformat/tls.c

@@ -89,7 +89,7 @@ int ff_tls_open_underlying(TLSShared *c, URLContext *parent, const char *uri, AV
     if (!c->host && !(c->host = av_strdup(c->underlying_host)))
         return AVERROR(ENOMEM);
 
-    proxy_path = getenv("http_proxy");
+    proxy_path = c->http_proxy ? c->http_proxy : getenv("http_proxy");
     use_proxy = !ff_http_match_no_proxy(getenv("no_proxy"), c->underlying_host) &&
                 proxy_path && av_strstart(proxy_path, "http://", NULL);
 

libavformat/tls.h

@@ -34,6 +34,7 @@ typedef struct TLSShared {
     int listen;
 
     char *host;
+    char *http_proxy;
 
     char underlying_host[200];
     int numerichost;
@@ -49,7 +50,8 @@ typedef struct TLSShared {
     {"cert_file",  "Certificate file",                    offsetof(pstruct, options_field . cert_file), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \
     {"key_file",   "Private key file",                    offsetof(pstruct, options_field . key_file),  AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \
     {"listen",     "Listen for incoming connections",     offsetof(pstruct, options_field . listen),    AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, .flags = TLS_OPTFL }, \
-    {"verifyhost", "Verify against a specific hostname",  offsetof(pstruct, options_field . host),      AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }
+    {"verifyhost", "Verify against a specific hostname",  offsetof(pstruct, options_field . host),      AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }, \
+    {"http_proxy", "Set proxy to tunnel through",         offsetof(pstruct, options_field . http_proxy), AV_OPT_TYPE_STRING, .flags = TLS_OPTFL }
 
 int ff_tls_open_underlying(TLSShared *c, URLContext *parent, const char *uri, AVDictionary **options);