[libvirt] [PATCH 2/3] esx: Extend esxVI_CURL_Download for partial downloads

[Doug Goldstein]

On Mon, Jul 2, 2012 at 4:44 PM, Matthias Bolte
<matthias.bolte at googlemail.com> wrote:
> ---
>  src/esx/esx_driver.c |    2 +-
>  src/esx/esx_vi.c     |   27 +++++++++++++++++++++++++--
>  src/esx/esx_vi.h     |    3 ++-
>  3 files changed, 28 insertions(+), 4 deletions(-)
>
> diff --git a/src/esx/esx_driver.c b/src/esx/esx_driver.c
> index db2144c..95b9286 100644
> --- a/src/esx/esx_driver.c
> +++ b/src/esx/esx_driver.c
> @@ -2802,7 +2802,7 @@ esxDomainGetXMLDesc(virDomainPtr domain, unsigned int flags)
>
>      url = virBufferContentAndReset(&buffer);
>
> -    if (esxVI_CURL_Download(priv->primary->curl, url, &vmx) < 0) {
> +    if (esxVI_CURL_Download(priv->primary->curl, url, &vmx, 0, NULL) < 0) {
>          goto cleanup;
>      }
>
> diff --git a/src/esx/esx_vi.c b/src/esx/esx_vi.c
> index 48718b6..3f8d745 100644
> --- a/src/esx/esx_vi.c
> +++ b/src/esx/esx_vi.c
> @@ -355,8 +355,10 @@ esxVI_CURL_Connect(esxVI_CURL *curl, esxUtil_ParsedUri *parsedUri)
>  }
>
>  int
> -esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content)
> +esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content,
> +                    unsigned long long offset, unsigned long long *length)
>  {
> +    char *range = NULL;
>      virBuffer buffer = VIR_BUFFER_INITIALIZER;
>      int responseCode = 0;
>
> @@ -365,9 +367,22 @@ esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content)
>          return -1;
>      }
>
> +    if (length != NULL && *length > 0) {
> +        if (virAsprintf(&range, "%llu-%llu", offset, offset + *length - 1) < 0) {
> +            virReportOOMError();
> +            goto cleanup;
> +        }
> +    } else if (offset > 0) {
> +        if (virAsprintf(&range, "%llu-", offset) < 0) {
> +            virReportOOMError();
> +            goto cleanup;
> +        }
> +    }
> +
>      virMutexLock(&curl->lock);
>
>      curl_easy_setopt(curl->handle, CURLOPT_URL, url);
> +    curl_easy_setopt(curl->handle, CURLOPT_RANGE, range);
>      curl_easy_setopt(curl->handle, CURLOPT_WRITEDATA, &buffer);
>      curl_easy_setopt(curl->handle, CURLOPT_UPLOAD, 0);
>      curl_easy_setopt(curl->handle, CURLOPT_HTTPGET, 1);
> @@ -378,7 +393,7 @@ esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content)
>
>      if (responseCode < 0) {
>          goto cleanup;
> -    } else if (responseCode != 200) {
> +    } else if (responseCode != 200 && responseCode != 206) {
>          ESX_VI_ERROR(VIR_ERR_INTERNAL_ERROR,
>                       _("HTTP response code %d for download from '%s'"),
>                       responseCode, url);
> @@ -390,9 +405,15 @@ esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content)
>          goto cleanup;
>      }
>
> +    if (length != NULL) {
> +        *length = virBufferUse(&buffer);
> +    }
> +
>      *content = virBufferContentAndReset(&buffer);
>
>    cleanup:
> +    VIR_FREE(range);
> +
>      if (*content == NULL) {
>          virBufferFreeAndReset(&buffer);
>          return -1;
> @@ -414,6 +435,7 @@ esxVI_CURL_Upload(esxVI_CURL *curl, const char *url, const char *content)
>      virMutexLock(&curl->lock);
>
>      curl_easy_setopt(curl->handle, CURLOPT_URL, url);
> +    curl_easy_setopt(curl->handle, CURLOPT_RANGE, NULL);
>      curl_easy_setopt(curl->handle, CURLOPT_READDATA, &content);
>      curl_easy_setopt(curl->handle, CURLOPT_UPLOAD, 1);
>      curl_easy_setopt(curl->handle, CURLOPT_INFILESIZE, strlen(content));
> @@ -1231,6 +1253,7 @@ esxVI_Context_Execute(esxVI_Context *ctx, const char *methodName,
>      virMutexLock(&ctx->curl->lock);
>
>      curl_easy_setopt(ctx->curl->handle, CURLOPT_URL, ctx->url);
> +    curl_easy_setopt(ctx->curl->handle, CURLOPT_RANGE, NULL);
>      curl_easy_setopt(ctx->curl->handle, CURLOPT_WRITEDATA, &buffer);
>      curl_easy_setopt(ctx->curl->handle, CURLOPT_UPLOAD, 0);
>      curl_easy_setopt(ctx->curl->handle, CURLOPT_POSTFIELDS, request);
> diff --git a/src/esx/esx_vi.h b/src/esx/esx_vi.h
> index 9560bd2..49b7ca2 100644
> --- a/src/esx/esx_vi.h
> +++ b/src/esx/esx_vi.h
> @@ -167,7 +167,8 @@ struct _esxVI_CURL {
>  int esxVI_CURL_Alloc(esxVI_CURL **curl);
>  void esxVI_CURL_Free(esxVI_CURL **curl);
>  int esxVI_CURL_Connect(esxVI_CURL *curl, esxUtil_ParsedUri *parsedUri);
> -int esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content);
> +int esxVI_CURL_Download(esxVI_CURL *curl, const char *url, char **content,
> +                        unsigned long long offset, unsigned long long *length);
>  int esxVI_CURL_Upload(esxVI_CURL *curl, const char *url, const char *content);
>
>
> --
> 1.7.4.1

This patch technically allows you to operate with ranges larger than
an unsigned int due to the use of unsigned long long. But virBuffer
can only work with unsigned ints. So there's a very real possibility
to overflow the type here when performing a download over the 4GB
mark. Since the content can only be in 1 file, this is a very real
possibility.

-- 
Doug Goldstein