curl: Allow a cookie or cookies to be sent with http/https requests.

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>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

2 files changed, 21 insertions, 0 deletions

diff --git a/block/curl.c b/block/curl.c
index 2698ae31e8..9051bc05c1 100644
--- a/block/curl.c
+++ b/block/curl.c
@@ -73,6 +73,7 @@ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
 #define CURL_BLOCK_OPT_READAHEAD "readahead"
 #define CURL_BLOCK_OPT_SSLVERIFY "sslverify"
 #define CURL_BLOCK_OPT_TIMEOUT "timeout"
+#define CURL_BLOCK_OPT_COOKIE    "cookie"
 
 struct BDRVCURLState;
 
@@ -112,6 +113,7 @@ typedef struct BDRVCURLState {
     size_t readahead_size;
     bool sslverify;
     int timeout;
+    char *cookie;
     bool accept_range;
     AioContext *aio_context;
 } BDRVCURLState;
@@ -385,6 +387,9 @@ static CURLState *curl_init_state(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, s->timeout);
         curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION,
                          (void *)curl_read_cb);
@@ -497,6 +502,11 @@ static QemuOptsList runtime_opts = {
             .type = QEMU_OPT_NUMBER,
             .help = "Curl timeout"
         },
+        {
+            .name = CURL_BLOCK_OPT_COOKIE,
+            .type = QEMU_OPT_STRING,
+            .help = "Pass the cookie or list of cookies with each request"
+        },
         { /* end of list */ }
     },
 };
@@ -509,6 +519,7 @@ 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;
@@ -538,6 +549,9 @@ 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);
+    s->cookie = g_strdup(cookie);
+
     file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL);
     if (file == NULL) {
         error_setg(errp, "curl block driver requires an 'url' option");
@@ -593,6 +607,7 @@ 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;
@@ -695,6 +710,7 @@ 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 52d56f4a1c..5479cf54f4 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2352,6 +2352,11 @@ multiple of 512 bytes. It defaults to 256k.
 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.
+
 @item timeout
 Set the timeout in seconds of the CURL connection. This timeout is the time
 that CURL waits for a response from the remote server to get the size of the