Re: [PATCH v6 06/12] test-http-server: add HTTP request parsing
- From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
- Date
- Jan 18, 2023, 11:14 UTC
- Message-ID
- <230118.86bkmwxf6e.gmgdl@evledraar.gmail.com>
- In-Reply-To
- <252098db219574527c587bc601565eab81b40c2c.1674012618.git.gitgitgadget@gmail.com>
On Wed, Jan 18 2023, Matthew John Cheetham via GitGitGadget wrote:
Show 42 quoted lines
> From: Matthew John Cheetham <mjcheetham@outlook.com>
>
> Add ability to parse HTTP requests to the test-http-server test helper.
>
> Signed-off-by: Matthew John Cheetham <mjcheetham@outlook.com>
> ---
> t/helper/test-http-server.c | 175 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 173 insertions(+), 2 deletions(-)
>
> diff --git a/t/helper/test-http-server.c b/t/helper/test-http-server.c
> index 6cdac223a55..36f4a54fe6d 100644
> --- a/t/helper/test-http-server.c
> +++ b/t/helper/test-http-server.c
> @@ -83,6 +83,42 @@ enum worker_result {
> WR_HANGUP = 1<<1,
> };
>
> +/*
> + * Fields from a parsed HTTP request.
> + */
> +struct req {
> + struct strbuf start_line;
> +
> + const char *method;
> + const char *http_version;
> +
> + struct strbuf uri_path;
> + struct strbuf query_args;
> +
> + struct string_list header_list;
> + const char *content_type;
> + ssize_t content_length;
> +};
> +
> +#define REQ__INIT { \
> + .start_line = STRBUF_INIT, \
> + .uri_path = STRBUF_INIT, \
> + .query_args = STRBUF_INIT, \
> + .header_list = STRING_LIST_INIT_NODUP, \
> + .content_type = NULL, \
> + .content_length = -1 \
> + }Style nit: Don't indent the trailing "}", and add a "," after the last "content_length" item.
We omit the comma by convention when there really should not be another item, such as when we have a "NULL" terminator, here though we might add a struct element at the end, so...
Show 77 quoted lines
> +static enum worker_result req__read(struct req *req, int fd)
> +{
> + struct strbuf h = STRBUF_INIT;
> + struct string_list start_line_fields = STRING_LIST_INIT_DUP;
> + int nr_start_line_fields;
> + const char *uri_target;
> + const char *query;
> + char *hp;
> + const char *hv;
> +
> + enum worker_result result = WR_OK;
> +
> + /*
> + * Read line 0 of the request and split it into component parts:
> + *
> + * <method> SP <uri-target> SP <HTTP-version> CRLF
> + *
> + */
> + if (strbuf_getwholeline_fd(&req->start_line, fd, '\n') == EOF) {
> + result = WR_OK | WR_HANGUP;
> + goto done;
> + }
> +
> + strbuf_trim_trailing_newline(&req->start_line);
> +
> + nr_start_line_fields = string_list_split(&start_line_fields,
> + req->start_line.buf,
> + ' ', -1);
> + if (nr_start_line_fields != 3) {
> + logerror("could not parse request start-line '%s'",
> + req->start_line.buf);
> + result = WR_IO_ERROR;
> + goto done;
> + }
> +
> + req->method = xstrdup(start_line_fields.items[0].string);
> + req->http_version = xstrdup(start_line_fields.items[2].string);
> +
> + uri_target = start_line_fields.items[1].string;
> +
> + if (strcmp(req->http_version, "HTTP/1.1")) {
> + logerror("unsupported version '%s' (expecting HTTP/1.1)",
> + req->http_version);
> + result = WR_IO_ERROR;
> + goto done;
> + }
> +
> + query = strchr(uri_target, '?');
> +
> + if (query) {
> + strbuf_add(&req->uri_path, uri_target, (query - uri_target));
> + strbuf_trim_trailing_dir_sep(&req->uri_path);
> + strbuf_addstr(&req->query_args, query + 1);
> + } else {
> + strbuf_addstr(&req->uri_path, uri_target);
> + strbuf_trim_trailing_dir_sep(&req->uri_path);
> + }
> +
> + /*
> + * Read the set of HTTP headers into a string-list.
> + */
> + while (1) {
> + if (strbuf_getwholeline_fd(&h, fd, '\n') == EOF)
> + goto done;
> + strbuf_trim_trailing_newline(&h);
> +
> + if (!h.len)
> + goto done; /* a blank line ends the header */
> +
> + hp = strbuf_detach(&h, NULL);
> + string_list_append(&req->header_list, hp);
> +
> + /* also store common request headers as struct req members */
> + if (skip_prefix(hp, "Content-Type: ", &hv)) {
> + req->content_type = hv;
> + } else if (skip_prefix(hp, "Content-Length: ", &hv)) {
> + req->content_length = strtol(hv, &hp, 10);In POSIX the "ssize_t" is not a "this is the unsigned size_t", but can be a much smaller integer type (although in practice it tends to be the signed version of "size_t".
But this seems like a potential overflow trap as a result, but sometimes we need to live with "ssize_t".
However, in this case it seems like we don't, as it seems the only reason you init'd this to -1 and then...
Show 9 quoted lines
> + if (trace2_is_enabled()) {
> + struct string_list_item *item;
> + trace2_printf("%s: %s", TR2_CAT, req->start_line.buf);
> + trace2_printf("%s: hver: %s", TR2_CAT, req->http_version);
> + trace2_printf("%s: hmth: %s", TR2_CAT, req->method);
> + trace2_printf("%s: path: %s", TR2_CAT, req->uri_path.buf);
> + trace2_printf("%s: qury: %s", TR2_CAT, req->query_args.buf);
> + if (req->content_length >= 0)
> + trace2_printf("%s: clen: %d", TR2_CAT, req->content_length);...use that ">= 0" is to keep the state of "did I assign to this above?
So firstly, shouldn't we error or something on a "Content-Length: 0", and aside from that wouldn't we just have a "int have_content_length = 0" in this function that we'd then flip to 1?