"max-blob-size" config var to limit generated HTML size

Sometimes it is not feasible to generate the HTML pretty-print for large
files, especially if a source-filter is involved or binary data is to be
displayed. The "max-blob-size" config var allows to disable HTML output
for blobs bigger than X KBytes. Plain downloads are not affected.

Signed-off-by: Georg Lukas <georg@op-co.de>

4 files changed, 14 insertions, 0 deletions

diff --git a/cgit.c b/cgit.c
index a17f40d..e1d38c2 100644
--- a/cgit.c
+++ b/cgit.c
@@ -144,48 +144,50 @@ void config_cb(const char *name, const char *value)
         else if (!strcmp(name, "cache-size"))
                 ctx.cfg.cache_size = atoi(value);
         else if (!strcmp(name, "cache-root"))
                 ctx.cfg.cache_root = xstrdup(value);
         else if (!strcmp(name, "cache-root-ttl"))
                 ctx.cfg.cache_root_ttl = atoi(value);
         else if (!strcmp(name, "cache-repo-ttl"))
                 ctx.cfg.cache_repo_ttl = atoi(value);
         else if (!strcmp(name, "cache-scanrc-ttl"))
                 ctx.cfg.cache_scanrc_ttl = atoi(value);
         else if (!strcmp(name, "cache-static-ttl"))
                 ctx.cfg.cache_static_ttl = atoi(value);
         else if (!strcmp(name, "cache-dynamic-ttl"))
                 ctx.cfg.cache_dynamic_ttl = atoi(value);
         else if (!strcmp(name, "about-filter"))
                 ctx.cfg.about_filter = new_filter(value, 0);
         else if (!strcmp(name, "commit-filter"))
                 ctx.cfg.commit_filter = new_filter(value, 0);
         else if (!strcmp(name, "embedded"))
                 ctx.cfg.embedded = atoi(value);
         else if (!strcmp(name, "max-message-length"))
                 ctx.cfg.max_msg_len = atoi(value);
         else if (!strcmp(name, "max-repodesc-length"))
                 ctx.cfg.max_repodesc_len = atoi(value);
+        else if (!strcmp(name, "max-blob-size"))
+                ctx.cfg.max_blob_size = atoi(value);
         else if (!strcmp(name, "max-repo-count"))
                 ctx.cfg.max_repo_count = atoi(value);
         else if (!strcmp(name, "max-commit-count"))
                 ctx.cfg.max_commit_count = atoi(value);
         else if (!strcmp(name, "scan-path"))
                 if (!ctx.cfg.nocache && ctx.cfg.cache_size)
                         process_cached_repolist(value);
                 else
                         scan_tree(value, repo_config);
         else if (!strcmp(name, "source-filter"))
                 ctx.cfg.source_filter = new_filter(value, 1);
         else if (!strcmp(name, "summary-log"))
                 ctx.cfg.summary_log = atoi(value);
         else if (!strcmp(name, "summary-branches"))
                 ctx.cfg.summary_branches = atoi(value);
         else if (!strcmp(name, "summary-tags"))
                 ctx.cfg.summary_tags = atoi(value);
         else if (!strcmp(name, "agefile"))
                 ctx.cfg.agefile = xstrdup(value);
         else if (!strcmp(name, "renamelimit"))
                 ctx.cfg.renamelimit = atoi(value);
         else if (!strcmp(name, "robots"))
                 ctx.cfg.robots = xstrdup(value);
         else if (!strcmp(name, "clone-prefix"))
@@ -249,48 +251,49 @@ char *xstrdupn(const char *str)
 }
 
 static void prepare_context(struct cgit_context *ctx)
 {
         memset(ctx, 0, sizeof(ctx));
         ctx->cfg.agefile = "info/web/last-modified";
         ctx->cfg.nocache = 0;
         ctx->cfg.cache_size = 0;
         ctx->cfg.cache_dynamic_ttl = 5;
         ctx->cfg.cache_max_create_time = 5;
         ctx->cfg.cache_repo_ttl = 5;
         ctx->cfg.cache_root = CGIT_CACHE_ROOT;
         ctx->cfg.cache_root_ttl = 5;
         ctx->cfg.cache_scanrc_ttl = 15;
         ctx->cfg.cache_static_ttl = -1;
         ctx->cfg.css = "/cgit.css";
         ctx->cfg.logo = "/cgit.png";
         ctx->cfg.local_time = 0;
         ctx->cfg.enable_tree_linenumbers = 1;
         ctx->cfg.max_repo_count = 50;
         ctx->cfg.max_commit_count = 50;
         ctx->cfg.max_lock_attempts = 5;
         ctx->cfg.max_msg_len = 80;
         ctx->cfg.max_repodesc_len = 80;
+        ctx->cfg.max_blob_size = 0;
         ctx->cfg.max_stats = 0;
         ctx->cfg.module_link = "./?repo=%s&page=commit&id=%s";
         ctx->cfg.renamelimit = -1;
         ctx->cfg.robots = "index, nofollow";
         ctx->cfg.root_title = "Git repository browser";
         ctx->cfg.root_desc = "a fast webinterface for the git dscm";
         ctx->cfg.script_name = CGIT_SCRIPT_NAME;
         ctx->cfg.section = "";
         ctx->cfg.summary_branches = 10;
         ctx->cfg.summary_log = 10;
         ctx->cfg.summary_tags = 10;
         ctx->env.cgit_config = xstrdupn(getenv("CGIT_CONFIG"));
         ctx->env.http_host = xstrdupn(getenv("HTTP_HOST"));
         ctx->env.https = xstrdupn(getenv("HTTPS"));
         ctx->env.no_http = xstrdupn(getenv("NO_HTTP"));
         ctx->env.path_info = xstrdupn(getenv("PATH_INFO"));
         ctx->env.query_string = xstrdupn(getenv("QUERY_STRING"));
         ctx->env.request_method = xstrdupn(getenv("REQUEST_METHOD"));
         ctx->env.script_name = xstrdupn(getenv("SCRIPT_NAME"));
         ctx->env.server_name = xstrdupn(getenv("SERVER_NAME"));
         ctx->env.server_port = xstrdupn(getenv("SERVER_PORT"));
         ctx->page.mimetype = "text/html";
         ctx->page.charset = PAGE_ENCODING;
         ctx->page.filename = NULL;
diff --git a/cgit.h b/cgit.h
index 6c6c460..39853df 100644
--- a/cgit.h
+++ b/cgit.h
@@ -164,48 +164,49 @@ struct cgit_config {
         char *root_desc;
         char *root_readme;
         char *script_name;
         char *section;
         char *virtual_root;
         int cache_size;
         int cache_dynamic_ttl;
         int cache_max_create_time;
         int cache_repo_ttl;
         int cache_root_ttl;
         int cache_scanrc_ttl;
         int cache_static_ttl;
         int embedded;
         int enable_filter_overrides;
         int enable_index_links;
         int enable_log_filecount;
         int enable_log_linecount;
         int enable_tree_linenumbers;
         int local_time;
         int max_repo_count;
         int max_commit_count;
         int max_lock_attempts;
         int max_msg_len;
         int max_repodesc_len;
+        int max_blob_size;
         int max_stats;
         int nocache;
         int noplainemail;
         int noheader;
         int renamelimit;
         int snapshots;
         int summary_branches;
         int summary_log;
         int summary_tags;
         struct string_list mimetypes;
         struct cgit_filter *about_filter;
         struct cgit_filter *commit_filter;
         struct cgit_filter *source_filter;
 };
 
 struct cgit_page {
         time_t modified;
         time_t expires;
         size_t size;
         char *mimetype;
         char *charset;
         char *filename;
         char *etag;
         char *title;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 0c13485..e69140b 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -156,48 +156,52 @@ logo::
         Url which specifies the source of an image which will be used as a logo
         on all cgit pages. Default value: "/cgit.png".
 
 logo-link::
         Url loaded when clicking on the cgit logo image. If unspecified the
         calculated url of the repository index page will be used. Default
         value: none.
 
 max-commit-count::
         Specifies the number of entries to list per page in "log" view. Default
         value: "50".
 
 max-message-length::
         Specifies the maximum number of commit message characters to display in
         "log" view. Default value: "80".
 
 max-repo-count::
                 Specifies the number of entries to list per page on therepository
         index page. Default value: "50".
 
 max-repodesc-length::
         Specifies the maximum number of repo description characters to display
         on the repository index page. Default value: "80".
 
+max-blob-size::
+        Specifies the maximum size of a blob to display HTML for in KBytes.
+        Default value: "0" (limit disabled).
+
 max-stats::
         Set the default maximum statistics period. Valid values are "week",
         "month", "quarter" and "year". If unspecified, statistics are
         disabled. Default value: none. See also: "repo.max-stats".
 
 mimetype.<ext>::
         Set the mimetype for the specified filename extension. This is used
         by the `plain` command when returning blob content.
 
 module-link::
         Text which will be used as the formatstring for a hyperlink when a
         submodule is printed in a directory listing. The arguments for the
         formatstring are the path and SHA1 of the submodule commit. Default
         value: "./?repo=%s&page=commit&id=%s"
 
 nocache::
         If set to the value "1" caching will be disabled. This settings is
         deprecated, and will not be honored starting with cgit-1.0. Default
         value: "0".
 
 noplainemail::
         If set to "1" showing full author email adresses will be disabled.
         Default value: "0".
 
diff --git a/ui-tree.c b/ui-tree.c
index f53ab64..f281937 100644
--- a/ui-tree.c
+++ b/ui-tree.c
@@ -86,48 +86,54 @@ static void print_object(const unsigned char *sha1, char *path, const char *base
 {
         enum object_type type;
         char *buf;
         unsigned long size;
 
         type = sha1_object_info(sha1, &size);
         if (type == OBJ_BAD) {
                 cgit_print_error(fmt("Bad object name: %s",
                                      sha1_to_hex(sha1)));
                 return;
         }
 
         buf = read_sha1_file(sha1, &type, &size);
         if (!buf) {
                 cgit_print_error(fmt("Error reading object %s",
                                      sha1_to_hex(sha1)));
                 return;
         }
 
         html(" (");
         cgit_plain_link("plain", NULL, NULL, ctx.qry.head,
                         curr_rev, path);
         htmlf(")<br/>blob: %s\n", sha1_to_hex(sha1));
 
+        if (ctx.cfg.max_blob_size && size / 1024 > ctx.cfg.max_blob_size) {
+                htmlf("<div class='error'>blob size (%dKB) exceeds display size limit (%dKB).</div>",
+                                size / 1024, ctx.cfg.max_blob_size);
+                return;
+        }
+
         if (buffer_is_binary(buf, size))
                 print_binary_buffer(buf, size);
         else
                 print_text_buffer(basename, buf, size);
 }
 
 
 static int ls_item(const unsigned char *sha1, const char *base, int baselen,
                    const char *pathname, unsigned int mode, int stage,
                    void *cbdata)
 {
         char *name;
         char *fullpath;
         char *class;
         enum object_type type;
         unsigned long size = 0;
 
         name = xstrdup(pathname);
         fullpath = fmt("%s%s%s", ctx.qry.path ? ctx.qry.path : "",
                        ctx.qry.path ? "/" : "", name);
 
         if (!S_ISGITLINK(mode)) {
                 type = sha1_object_info(sha1, &size);
                 if (type == OBJ_BAD) {