Implement HEAD support

main.c

@@ -980,6 +980,61 @@ end:
     return ret;
 }
 
+static int getnode_head(const struct http_payload *const p,
+    struct http_response *const r, void *const user)
+{
+    struct auth *const a = user;
+
+    if (auth_cookie(a, &p->cookie))
+    {
+        fprintf(stderr, "%s: auth_cookie failed\n", __func__);
+        return page_forbidden(r);
+    }
+
+    const char *const username = p->cookie.field,
+        *const resource = p->resource + strlen("/user/");
+
+    if (path_invalid(resource))
+    {
+        fprintf(stderr, "%s: illegal relative path %s\n", __func__, resource);
+        return page_forbidden(r);
+    }
+
+    int ret = -1;
+    struct dynstr dir, root, d;
+    const char *const adir = auth_dir(a),
+        *const sep = p->resource[strlen(p->resource) - 1] != '/' ? "/" : "";
+
+    dynstr_init(&dir);
+    dynstr_init(&d);
+    dynstr_init(&root);
+
+    if (!adir)
+    {
+        fprintf(stderr, "%s: auth_dir failed\n", __func__);
+        goto end;
+    }
+    else if (dynstr_append(&dir, "%s%s", p->resource, sep))
+    {
+        fprintf(stderr, "%s: dynstr_append dird failed\n", __func__);
+        goto end;
+    }
+    else if (dynstr_append(&root, "%s/user/%s/", adir, username)
+        || dynstr_append(&d, "%s%s", root.str, resource))
+    {
+        fprintf(stderr, "%s: dynstr_append failed\n", __func__);
+        goto end;
+    }
+
+    ret = page_head_resource(r, d.str);
+
+end:
+    dynstr_free(&dir);
+    dynstr_free(&d);
+    dynstr_free(&root);
+    return ret;
+}
+
 static int move_file(const char *const old, const char *const new)
 {
     int ret = -1;
@@ -1924,6 +1979,7 @@ static int add_urls(struct handler *const h, void *const user)
         {.url = "/index.html", .op = HTTP_OP_GET, .f = serve_index},
         {.url = "/style.css", .op = HTTP_OP_GET, .f = serve_style},
         {.url = "/user/*", .op = HTTP_OP_GET, .f = getnode},
+        {.url = "/user/*", .op = HTTP_OP_HEAD, .f = getnode_head},
         {.url = "/login", .op = HTTP_OP_POST, .f = login},
         {.url = "/logout", .op = HTTP_OP_POST, .f = logout},
         {.url = "/public/*", .op = HTTP_OP_GET, .f = getpublic},

page.c

@@ -2199,3 +2199,36 @@ end:
 
     return ret;
 }
+
+int page_head_resource(struct http_response *const r, const char *const res)
+{
+    struct stat sb;
+
+    if (stat(res, &sb))
+    {
+        if (errno == ENOENT || errno == ENOTDIR)
+            return page_not_found(r);
+        else
+        {
+            fprintf(stderr, "%s: stat(2) %s: %s\n",
+                __func__, res, strerror(errno));
+            return -1;
+        }
+    }
+
+    const mode_t m = sb.st_mode;
+
+    if (!S_ISDIR(m) && !S_ISREG(m))
+    {
+        fprintf(stderr, "%s: unexpected st_mode %jd\n", __func__, (intmax_t)m);
+        return -1;
+    }
+
+    *r = (const struct http_response)
+    {
+        .status = HTTP_STATUS_OK,
+        .n = sb.st_size
+    };
+
+    return 0;
+}

page.h

@@ -43,6 +43,7 @@ int page_failed_login(struct http_response *r);
 int page_forbidden(struct http_response *r);
 int page_bad_request(struct http_response *r);
 int page_resource(const struct page_resource *r);
+int page_head_resource(struct http_response *r, const char *res);
 int page_public(struct http_response *r, const char *res);
 int page_share(struct http_response *r, const char *path);
 int page_quota_exceeded(struct http_response *r, unsigned long long len,