[http] Add support for HTTP POST

Allow HTTP POST requests to be generated when the URI includes a
parameter list.  For example:

  #!ipxe
  params
  param mac ${net0/mac}
  param uuid ${uuid}
  param asset ${asset}
  chain http://boot.ipxe.org/demo/boot.php##params

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/net/tcp/httpcore.c b/src/net/tcp/httpcore.c
index bccb35f5f4b7bacc84e73fb41e16bac0df459ee0..bfa7d7f775869802f9ca9cdf39d1154f053394b8 100644 (file)
--- a/src/net/tcp/httpcore.c
+++ b/src/net/tcp/httpcore.c
@@ -49,6 +49,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/blockdev.h>
 #include <ipxe/acpi.h>
 #include <ipxe/version.h>
+#include <ipxe/params.h>
 #include <ipxe/http.h>
 
 /* Disambiguate the various error causes */
@@ -1059,17 +1060,101 @@ static char * http_digest_auth ( struct http_request *http,
        return auth;
 }
 
+/**
+ * Generate HTTP POST parameter list
+ *
+ * @v http             HTTP request
+ * @v buf              Buffer to contain HTTP POST parameters
+ * @v len              Length of buffer
+ * @ret len            Length of parameter list (excluding terminating NUL)
+ */
+static size_t http_post_params ( struct http_request *http,
+                                char *buf, size_t len ) {
+       struct parameter *param;
+       ssize_t remaining = len;
+       size_t frag_len;
+
+       /* Add each parameter in the form "key=value", joined with "&" */
+       len = 0;
+       for_each_param ( param, http->uri->params ) {
+
+               /* Add the "&", if applicable */
+               if ( len ) {
+                       if ( remaining > 0 )
+                               *buf = '&';
+                       buf++;
+                       len++;
+                       remaining--;
+               }
+
+               /* URI-encode the key */
+               frag_len = uri_encode ( param->key, buf, remaining, 0 );
+               buf += frag_len;
+               len += frag_len;
+               remaining -= frag_len;
+
+               /* Add the "=" */
+               if ( remaining > 0 )
+                       *buf = '=';
+               buf++;
+               len++;
+               remaining--;
+
+               /* URI-encode the value */
+               frag_len = uri_encode ( param->value, buf, remaining, 0 );
+               buf += frag_len;
+               len += frag_len;
+               remaining -= frag_len;
+       }
+
+       /* Ensure string is NUL-terminated even if no parameters are present */
+       if ( remaining > 0 )
+               *buf = '\0';
+
+       return len;
+}
+
+/**
+ * Generate HTTP POST body
+ *
+ * @v http             HTTP request
+ * @ret post           I/O buffer containing POST body, or NULL on error
+ */
+static struct io_buffer * http_post ( struct http_request *http ) {
+       struct io_buffer *post;
+       size_t len;
+       size_t check_len;
+
+       /* Calculate length of parameter list */
+       len = http_post_params ( http, NULL, 0 );
+
+       /* Allocate parameter list */
+       post = alloc_iob ( len + 1 /* NUL */ );
+       if ( ! post )
+               return NULL;
+
+       /* Fill parameter list */
+       check_len = http_post_params ( http, iob_put ( post, len ),
+                                      ( len + 1 /* NUL */ ) );
+       assert ( len == check_len );
+       DBGC ( http, "HTTP %p POST %s\n", http, ( ( char * ) post->data ) );
+
+       return post;
+}
+
 /**
  * HTTP process
  *
  * @v http             HTTP request
  */
 static void http_step ( struct http_request *http ) {
+       struct io_buffer *post;
        size_t uri_len;
        char *method;
        char *uri;
        char *range;
        char *auth;
+       char *content;
        int len;
        int rc;
 
@@ -1088,7 +1173,8 @@ static void http_step ( struct http_request *http ) {
        }
 
        /* Determine method */
-       method = ( ( http->flags & HTTP_HEAD_ONLY ) ? "HEAD" : "GET" );
+       method = ( ( http->flags & HTTP_HEAD_ONLY ) ? "HEAD" :
+                  ( http->uri->params ? "POST" : "GET" ) );
 
        /* Construct path?query request */
        uri_len = ( unparse_uri ( NULL, 0, http->uri,
@@ -1136,6 +1222,25 @@ static void http_step ( struct http_request *http ) {
                auth = NULL;
        }
 
+       /* Construct POST content, if applicable */
+       if ( http->uri->params ) {
+               post = http_post ( http );
+               if ( ! post ) {
+                       rc = -ENOMEM;
+                       goto err_post;
+               }
+               len = asprintf ( &content, "Content-Type: "
+                                "application/x-www-form-urlencoded\r\n"
+                                "Content-Length: %zd\r\n", iob_len ( post ) );
+               if ( len < 0 ) {
+                       rc = len;
+                       goto err_content;
+               }
+       } else {
+               post = NULL;
+               content = NULL;
+       }
+
        /* Mark request as transmitted */
        http->flags &= ~HTTP_TX_PENDING;
 
@@ -1144,7 +1249,7 @@ static void http_step ( struct http_request *http ) {
                                  "%s %s HTTP/1.1\r\n"
                                  "User-Agent: iPXE/%s\r\n"
                                  "Host: %s%s%s\r\n"
-                                 "%s%s%s"
+                                 "%s%s%s%s"
                                  "\r\n",
                                  method, uri, product_version, http->uri->host,
                                  ( http->uri->port ?
@@ -1154,11 +1259,24 @@ static void http_step ( struct http_request *http ) {
                                  ( ( http->flags & HTTP_CLIENT_KEEPALIVE ) ?
                                    "Connection: keep-alive\r\n" : "" ),
                                  ( range ? range : "" ),
-                                 ( auth ? auth : "" ) ) ) != 0 ) {
+                                 ( auth ? auth : "" ),
+                                 ( content ? content : "" ) ) ) != 0 ) {
                goto err_xfer;
        }
 
+       /* Send POST content, if applicable */
+       if ( post ) {
+               if ( ( rc = xfer_deliver_iob ( &http->socket,
+                                              iob_disown ( post ) ) ) != 0 )
+                       goto err_xfer_post;
+       }
+
+ err_xfer_post:
  err_xfer:
+       free ( content );
+ err_content:
+       free ( post );
+ err_post:
        free ( auth );
  err_auth:
        free ( range );