[Qemu-devel] [PATCH] curl: Allow a cookie or cookies to be sent with http/https requests.

["Richard W.M. Jones" <rjones@redhat.com>]

In order to access VMware ESX efficiently, we need to send a session
cookie.  This patch is very simple and just allows you to send that
session cookie.  It punts on the question of how you get the session
cookie in the first place, but in practice you can just run a `curl'
command against the server and extract the cookie that way.

To use it, add file.cookie to the curl URL.  For example:

$ qemu-img info 'json: {
    "file.driver":"https",
    "file.url":"https://vcenter/folder/Windows%202003/Windows%202003-flat.vmdk?dcPath=Datacenter&dsName=datastore1",
    "file.sslverify":"off",
    "file.cookie":"vmware_soap_session=\"52a01262-bf93-ccce-d379-8dabb3e55560\""}'
image: [...]
file format: raw
virtual size: 8.0G (8589934592 bytes)
disk size: unavailable

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
---
 block/curl.c    | 20 ++++++++++++++++++++
 qemu-options.hx |  5 +++++
 2 files changed, 25 insertions(+)

diff --git a/block/curl.c b/block/curl.c
index f59615d..c1c2e35 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -71,6 +71,7 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
 #define CURL_BLOCK_OPT_URL       "url"
 #define CURL_BLOCK_OPT_READAHEAD "readahead"
 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
+#define CURL_BLOCK_OPT_COOKIE    "cookie"
 
 struct BDRVCURLState;
 
@@ -109,6 +110,7 @@ typedef struct BDRVCURLState {
     char *url;
     size_t readahead_size;
     bool sslverify;
+    char *cookie;
     bool accept_range;
     AioContext *aio_context;
 } BDRVCURLState;
@@ -382,6 +384,9 @@ static CURLState *curl_init_state(BlockDriverState *bs, BDRVCURLState *s)
         curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
         curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
                          (long) s->sslverify);
+        if (s->cookie) {
+            curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie);
+        }
         curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
                          (void *)curl_read_cb);
@@ -489,6 +494,11 @@ static QemuOptsList runtime_opts = {
             .type = QEMU_OPT_BOOL,
             .help = "Verify SSL certificate"
         },
+        {
+            .name = CURL_BLOCK_OPT_COOKIE,
+            .type = QEMU_OPT_STRING,
+            .help = "Pass the cookie or list of cookies with each request"
+        },
         { /* end of list */ }
     },
 };
@@ -501,6 +511,7 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
     QemuOpts *opts;
     Error *local_err = NULL;
     const char *file;
+    const char *cookie;
     double d;
 
     static int inited = 0;
@@ -527,6 +538,13 @@ static int curl_open(BlockDriverState *bs, QDict *options, int flags,
 
     s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true);
 
+    cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
+    if (cookie) {
+        s->cookie = g_strdup(cookie);
+    } else {
+        s->cookie = NULL;
+    }
+
     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
     if (file == NULL) {
         error_setg(errp, "curl block driver requires an 'url' option");
@@ -582,6 +600,7 @@ out:
     curl_easy_cleanup(state->curl);
     state->curl = NULL;
 out_noclean:
+    g_free(s->cookie);
     g_free(s->url);
     qemu_opts_del(opts);
     return -EINVAL;
@@ -684,6 +703,7 @@ static void curl_close(BlockDriverState *bs)
     DPRINTF("CURL: Close\n");
     curl_detach_aio_context(bs);
 
+    g_free(s->cookie);
     g_free(s->url);
 }
 
diff --git a/qemu-options.hx b/qemu-options.hx
index c573dd8..7b4a58a 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2351,6 +2351,11 @@ multiple of 512 bytes. It defaults to 256k.
 @item sslverify
 Whether to verify the remote server's certificate when connecting over SSL. It
 can have the value 'on' or 'off'. It defaults to 'on'.
+
+@item cookie
+Send this cookie (it can also be a list of cookies separated by ';') with
+each outgoing request.  Only supported when using protocols such as HTTP
+which support cookies, otherwise ignored.
 @end table
 
 Note that when passing options to qemu explicitly, @option{driver} is the value
-- 
2.0.4