From 211dd1e9c54a9ba92e2e648acacbc18981374073 Mon Sep 17 00:00:00 2001 From: Jim Fehlig Date: Wed, 2 Jun 2010 18:07:17 -0600 Subject: [PATCH] Allocate buffer to hold xend response There are cases when a response from xend can exceed 4096 bytes, in which case anything beyond 4096 is ignored. This patch changes the current fixed-size, stack-allocated buffer to a dynamically allocated buffer based on Content-Length in HTTP header. --- src/xen/xend_internal.c | 80 +++++++++++++++++++++-------------------- 1 file changed, 41 insertions(+), 39 deletions(-) diff --git a/src/xen/xend_internal.c b/src/xen/xend_internal.c index e763baddb6..0c1a738a5e 100644 --- a/src/xen/xend_internal.c +++ b/src/xen/xend_internal.c @@ -302,17 +302,19 @@ istartswith(const char *haystack, const char *needle) * xend_req: * @fd: the file descriptor * @content: the buffer to store the content - * @n_content: the size of the buffer * * Read the HTTP response from a Xen Daemon request. + * If the response contains content, memory is allocated to + * hold the content. * - * Returns the HTTP return code. + * Returns the HTTP return code and @content is set to the + * allocated memory containing HTTP content. */ static int -xend_req(int fd, char *content, size_t n_content) +xend_req(int fd, char **content) { char buffer[4096]; - int content_length = -1; + int content_length = 0; int retcode = 0; while (sreads(fd, buffer, sizeof(buffer)) > 0) { @@ -325,19 +327,17 @@ xend_req(int fd, char *content, size_t n_content) retcode = atoi(buffer + 9); } - if (content_length > -1) { + if (content_length > 0) { ssize_t ret; - if ((unsigned int) content_length > (n_content + 1)) - content_length = n_content - 1; + if (VIR_ALLOC_N(*content, content_length) < 0 ) { + virReportOOMError(); + return -1; + } - ret = sread(fd, content, content_length); + ret = sread(fd, *content, content_length); if (ret < 0) return -1; - - content[ret] = 0; - } else { - content[0] = 0; } return retcode; @@ -348,7 +348,6 @@ xend_req(int fd, char *content, size_t n_content) * @xend: pointer to the Xen Daemon structure * @path: the path used for the HTTP request * @content: the buffer to store the content - * @n_content: the size of the buffer * * Do an HTTP GET RPC with the Xen Daemon * @@ -356,7 +355,7 @@ xend_req(int fd, char *content, size_t n_content) */ static int xend_get(virConnectPtr xend, const char *path, - char *content, size_t n_content) + char **content) { int ret; int s = do_connect(xend); @@ -373,14 +372,15 @@ xend_get(virConnectPtr xend, const char *path, "Accept-Encoding: identity\r\n" "Content-Type: application/x-www-form-urlencoded\r\n" "\r\n"); - ret = xend_req(s, content, n_content); + ret = xend_req(s, content); close(s); if (((ret < 0) || (ret >= 300)) && ((ret != 404) || (!STRPREFIX(path, "/xend/domain/")))) { virXendError(VIR_ERR_GET_FAILED, _("%d status from xen daemon: %s:%s"), - ret, path, content); + ret, path, + content ? *content: "NULL"); } return ret; @@ -392,8 +392,6 @@ xend_get(virConnectPtr xend, const char *path, * @xend: pointer to the Xen Daemon structure * @path: the path used for the HTTP request * @ops: the information sent for the POST - * @content: the buffer to store the content - * @n_content: the size of the buffer * * Do an HTTP POST RPC with the Xen Daemon, this usually makes changes at the * Xen level. @@ -401,10 +399,10 @@ xend_get(virConnectPtr xend, const char *path, * Returns the HTTP return code or -1 in case or error. */ static int -xend_post(virConnectPtr xend, const char *path, const char *ops, - char *content, size_t n_content) +xend_post(virConnectPtr xend, const char *path, const char *ops) { char buffer[100]; + char *err_buf = NULL; int ret; int s = do_connect(xend); @@ -425,26 +423,28 @@ xend_post(virConnectPtr xend, const char *path, const char *ops, swrites(s, "\r\n\r\n"); swrites(s, ops); - ret = xend_req(s, content, n_content); + ret = xend_req(s, &err_buf); close(s); if ((ret < 0) || (ret >= 300)) { virXendError(VIR_ERR_POST_FAILED, - _("xend_post: error from xen daemon: %s"), content); - } else if ((ret == 202) && (strstr(content, "failed") != NULL)) { + _("xend_post: error from xen daemon: %s"), err_buf); + } else if ((ret == 202) && err_buf && (strstr(err_buf, "failed") != NULL)) { virXendError(VIR_ERR_POST_FAILED, - _("xend_post: error from xen daemon: %s"), content); + _("xend_post: error from xen daemon: %s"), err_buf); ret = -1; - } else if (((ret >= 200) && (ret <= 202)) && (strstr(content, "xend.err") != NULL)) { + } else if (((ret >= 200) && (ret <= 202)) && err_buf && + (strstr(err_buf, "xend.err") != NULL)) { /* This is to catch case of things like 'virsh dump Domain-0 foo' * which returns a success code, but the word 'xend.err' * in body to indicate error :-( */ virXendError(VIR_ERR_POST_FAILED, - _("xend_post: error from xen daemon: %s"), content); + _("xend_post: error from xen daemon: %s"), err_buf); ret = -1; } + VIR_FREE(err_buf); return ret; } #endif /* ! PROXY */ @@ -487,8 +487,6 @@ http2unix(int ret) * xend_op_ext: * @xend: pointer to the Xen Daemon structure * @path: path for the object - * @error: buffer for the error output - * @n_error: size of @error * @key: the key for the operation * @ap: input values to pass to the operation * @@ -497,8 +495,7 @@ http2unix(int ret) * Returns 0 in case of success, -1 in case of failure. */ static int -xend_op_ext(virConnectPtr xend, const char *path, char *error, - size_t n_error, const char *key, va_list ap) +xend_op_ext(virConnectPtr xend, const char *path, const char *key, va_list ap) { const char *k = key, *v; virBuffer buf = VIR_BUFFER_INITIALIZER; @@ -524,7 +521,7 @@ xend_op_ext(virConnectPtr xend, const char *path, char *error, } content = virBufferContentAndReset(&buf); - ret = http2unix(xend_post(xend, path, content, error, n_error)); + ret = http2unix(xend_post(xend, path, content)); VIR_FREE(content); return ret; @@ -535,8 +532,6 @@ xend_op_ext(virConnectPtr xend, const char *path, char *error, * xend_op: * @xend: pointer to the Xen Daemon structure * @name: the domain name target of this operation - * @error: buffer for the error output - * @n_error: size of @error * @key: the key for the operation * @ap: input values to pass to the operation * @...: input values to pass to the operation @@ -550,14 +545,13 @@ static int ATTRIBUTE_SENTINEL xend_op(virConnectPtr xend, const char *name, const char *key, ...) { char buffer[1024]; - char error[1024]; va_list ap; int ret; snprintf(buffer, sizeof(buffer), "/xend/domain/%s", name); va_start(ap, key); - ret = xend_op_ext(xend, buffer, error, sizeof(error), key, ap); + ret = xend_op_ext(xend, buffer, key, ap); va_end(ap); return ret; @@ -581,21 +575,29 @@ static struct sexpr *sexpr_get(virConnectPtr xend, const char *fmt, ...) static struct sexpr * sexpr_get(virConnectPtr xend, const char *fmt, ...) { - char buffer[4096]; + char *buffer = NULL; char path[1024]; va_list ap; int ret; + struct sexpr *res = NULL; va_start(ap, fmt); vsnprintf(path, sizeof(path), fmt, ap); va_end(ap); - ret = xend_get(xend, path, buffer, sizeof(buffer)); + ret = xend_get(xend, path, &buffer); ret = http2unix(ret); if (ret == -1) - return NULL; + goto cleanup; - return string2sexpr(buffer); + if (buffer == NULL) + goto cleanup; + + res = string2sexpr(buffer); + +cleanup: + VIR_FREE(buffer); + return res; } /**