Add HTTP op and resource to length callback

Users might want to know which HTTP operation (i.e., POST or PUT) and/or
resource is being requested before determining whether the request
should be accepted or not.

10 files changed, 39 insertions, 29 deletions

diff --git a/doc/man7/libweb_handler.7 b/doc/man7/libweb_handler.7
index 5398675..6a2c93e 100644
--- a/doc/man7/libweb_handler.7
+++ b/doc/man7/libweb_handler.7
@@ -73,7 +73,7 @@ defined as:
 struct handler_cfg
 {
     const char *\fItmpdir\fP;
-    int (*\fIlength\fP)(unsigned long long len, const struct http_cookie *c, struct http_response *r, void *user);
+    int (*\fIlength\fP)(enum http_op op, const char *res, unsigned long long len, const struct http_cookie *c, struct http_response *r, void *user);
     void *\fIuser\fP;
     size_t \fImax_headers\fP;
     struct http_cfg_post \fIpost\fP;
@@ -185,7 +185,7 @@ static int hello(const struct http_payload *const pl,
     return 0;
 }
 
-static int on_length(const unsigned long long len,
+static int on_length(const char *const res, const unsigned long long len,
     const struct http_cookie *const c, struct http_response *const r,
     void *const user)
 {
diff --git a/doc/man7/libweb_http.7 b/doc/man7/libweb_http.7
index 39fd4a5..ba32a99 100644
--- a/doc/man7/libweb_http.7
+++ b/doc/man7/libweb_http.7
@@ -90,7 +90,7 @@ struct http_cfg
     int (*\fIread\fP)(void *\fIbuf\fP, size_t \fIn\fP, void *\fIuser\fP);
     int (*\fIwrite\fP)(const void *\fIbuf\fP, size_t \fIn\fP, void *\fIuser\fP);
     int (*\fIpayload\fP)(const struct http_payload *\fIp\fP, struct http_response *\fIr\fP, void *\fIuser\fP);
-    int (*\fIlength\fP)(unsigned long long \fIlen\fP, const struct http_cookie *\fIc\fP, struct http_response *\fIr\fP, void *\fIuser\fP);
+    int (*\fIlength\fP)(enum http_op \fIop\fP, const char *\fIres\fP, unsigned long long \fIlen\fP, const struct http_cookie *\fIc\fP, struct http_response *\fIr\fP, void *\fIuser\fP);
     const char *\fItmpdir\fP;
     void *\fIuser\fP;
     size_t \fImax_headers\fP;
@@ -182,6 +182,11 @@ In the case of a
 request,
 .I len
 defines the length of the file body.
+.I op
+can be used to distinguish the request type,
+whereas
+.I res
+can be used to determine which resource is being accessed by the request.
 .I c
 is a read-only pointer to a
 .I "struct http_cookie"
@@ -200,8 +205,11 @@ only when the function returns a positive integer.
 This function returns zero on success, a negative integer in case
 of a fatal error or a positive integer in case of a non-fatal error
 caused by a malformed request, or to indicate a lack of support for
-this feature. When a positive integer is returned, the connection
-against the client shall be closed.
+this feature. When a positive integer is returned, the response pointed
+to by
+.I r
+is sent to the client and the connection
+against the client shall be closed afterwards.
 
 .I tmpdir
 is a null-terminated string defining the path to a directory where
diff --git a/examples/async/main.c b/examples/async/main.c
index fbd766e..8b0ec82 100644
--- a/examples/async/main.c
+++ b/examples/async/main.c
@@ -120,9 +120,9 @@ static int hello(const struct http_payload *const pl,
     return 0;
 }
 
-static int on_length(const unsigned long long len,
-    const struct http_cookie *const c, struct http_response *const r,
-    void *const user)
+static int on_length(const enum http_op op, const char *const res,
+    const unsigned long long len, const struct http_cookie *const c,
+    struct http_response *const r, void *const user)
 {
     *r = (const struct http_response)
     {
diff --git a/examples/headers/main.c b/examples/headers/main.c
index a4eb5e6..b9ed388 100644
--- a/examples/headers/main.c
+++ b/examples/headers/main.c
@@ -40,9 +40,9 @@ static int hello(const struct http_payload *const pl,
     return 0;
 }
 
-static int on_length(const unsigned long long len,
-    const struct http_cookie *const c, struct http_response *const r,
-    void *const user)
+static int on_length(const enum http_op op, const char *const res,
+    const unsigned long long len, const struct http_cookie *const c,
+    struct http_response *const r, void *const user)
 {
     *r = (const struct http_response)
     {
diff --git a/examples/hello/main.c b/examples/hello/main.c
index 8ddf691..cb5a8ee 100644
--- a/examples/hello/main.c
+++ b/examples/hello/main.c
@@ -77,9 +77,9 @@ end:
     return ret;
 }
 
-static int on_length(const unsigned long long len,
-    const struct http_cookie *const c, struct http_response *const r,
-    void *const user)
+static int on_length(const enum http_op op, const char *const res,
+    const unsigned long long len, const struct http_cookie *const c,
+    struct http_response *const r, void *const user)
 {
     *r = (const struct http_response)
     {
diff --git a/examples/put/main.c b/examples/put/main.c
index 3d6454d..562a1fa 100644
--- a/examples/put/main.c
+++ b/examples/put/main.c
@@ -40,9 +40,9 @@ static int on_put(const struct http_payload *const pl,
     return 0;
 }
 
-static int on_length(const unsigned long long len,
-    const struct http_cookie *const c, struct http_response *const r,
-    void *const user)
+static int on_length(const enum http_op op, const char *const res,
+    const unsigned long long len, const struct http_cookie *const c,
+    struct http_response *const r, void *const user)
 {
     *r = (const struct http_response)
     {
diff --git a/handler.c b/handler.c
index 455832b..a7f0303 100644
--- a/handler.c
+++ b/handler.c
@@ -93,9 +93,9 @@ static int on_payload(const struct http_payload *const p,
     return 0;
 }
 
-static int on_length(const unsigned long long len,
-    const struct http_cookie *const c, struct http_response *const r,
-    void *const user)
+static int on_length(const enum http_op op, const char *const res,
+    const unsigned long long len, const struct http_cookie *const c,
+    struct http_response *const r, void *const user)
 {
     struct client *const cl = user;
     struct handler *const h = cl->h;
@@ -107,9 +107,9 @@ static int on_length(const unsigned long long len,
     int ret;
 
     if (s->length)
-        ret = s->length(len, c, r, h->cfg.user, cl->args);
+        ret = s->length(op, res, len, c, r, h->cfg.user, cl->args);
     else
-        ret = h->cfg.length(len, c, r, h->cfg.user);
+        ret = h->cfg.length(op, res, len, c, r, h->cfg.user);
 
     if (!ret)
     {
diff --git a/http.c b/http.c
index 0fcae07..978eea6 100644
--- a/http.c
+++ b/http.c
@@ -1608,7 +1608,8 @@ static int check_length(struct http_ctx *const h)
         .value = c->value
     };
 
-    return h->cfg.length(c->u2.payload.len, &cookie, &h->wctx.r, h->cfg.user);
+    return h->cfg.length(c->op, c->resource, c->u2.payload.len, &cookie,
+        &h->wctx.r, h->cfg.user);
 }
 
 static int process_payload_expect(struct http_ctx *const h)
diff --git a/include/libweb/handler.h b/include/libweb/handler.h
index 97fdca0..9dacdbd 100644
--- a/include/libweb/handler.h
+++ b/include/libweb/handler.h
@@ -10,8 +10,8 @@ typedef int (*handler_fn)(const struct http_payload *p,
 struct handler_cfg
 {
     const char *tmpdir;
-    int (*length)(unsigned long long len, const struct http_cookie *c,
-        struct http_response *r, void *user);
+    int (*length)(enum http_op op, const char *res, unsigned long long len,
+        const struct http_cookie *c, struct http_response *r, void *user);
     void *user;
     size_t max_headers;
     struct http_cfg_post post;
diff --git a/include/libweb/http.h b/include/libweb/http.h
index bd7769e..ad4ebcd 100644
--- a/include/libweb/http.h
+++ b/include/libweb/http.h
@@ -115,8 +115,9 @@ struct http_response
 
     union http_step
     {
-        int (*length)(unsigned long long len, const struct http_cookie *c,
-            struct http_response *r, void *user, void *args);
+        int (*length)(enum http_op op, const char *res, unsigned long long len,
+            const struct http_cookie *c, struct http_response *r, void *user,
+            void *args);
         int (*payload)(const struct http_payload *p, struct http_response *r,
             void *user, void *args);
     } step;
@@ -128,8 +129,8 @@ struct http_cfg
     int (*write)(const void *buf, size_t n, void *user);
     int (*payload)(const struct http_payload *p, struct http_response *r,
         void *user);
-    int (*length)(unsigned long long len, const struct http_cookie *c,
-        struct http_response *r, void *user);
+    int (*length)(enum http_op op, const char *res, unsigned long long len,
+        const struct http_cookie *c, struct http_response *r, void *user);
     const char *tmpdir;
     void *user;
     size_t max_headers;