blogc-runserver: import external tool to blogc repository

still in the effort to reduce maintenance work, I'm importing
blogc-runserver tool to the main blogc repository.

the tool is build by default, if needed headers and libraries are
found.

1 files changed, 389 insertions, 0 deletions

diff --git a/src/blogc-runserver.c b/src/blogc-runserver.c
new file mode 100644
index 0000000..81bd5f9
--- /dev/null
+++ b/src/blogc-runserver.c
@@ -0,0 +1,389 @@
+/*
+ * blogc: A blog compiler.
+ * Copyright (C) 2015-2016 Rafael G. Martins <rafael@rafaelmartins.eng.br>
+ *
+ * This program can be distributed under the terms of the BSD License.
+ * See the file LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <event2/event.h>
+#include <event2/http.h>
+#include <event2/buffer.h>
+#include <event2/keyvalq_struct.h>
+#include <magic.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+
+/**
+ * this mapping is used to declare "supported" file types, that are forced over
+ * whatever detected by libmagic, but we will still use the charset provided by
+ * libmagic anyway. it also helps detecting index files when the client asks
+ * for a directory.
+ */
+static const struct content_type_map {
+    const char *mimetype;
+    const char *extension;
+    const char *index;
+} content_types[] = {
+    {"text/html", "html", "index.html"},
+    {"text/html", "htm", "index.htm"},
+    {"text/xml", "xml", "index.xml"},
+    {"text/plain", "txt", "index.txt"},
+    {"text/css", "css", NULL},
+    {"application/javascript", "js", NULL},
+    {NULL, NULL, NULL}
+};
+
+
+static magic_t magic_all = NULL;
+static magic_t magic_charset = NULL;
+
+
+static const char*
+get_extension(const char *filename)
+{
+    const char *ext = NULL;
+    unsigned int i;
+    for (i = strlen(filename); i > 0; i--) {
+        if (filename[i] == '.') {
+            ext = filename + i + 1;
+            break;
+        }
+    }
+    if (i == 0)
+        return NULL;
+    return ext;
+}
+
+
+static char*
+guess_content_type(const char *filename, int fd)
+{
+    int newfd;
+
+    // try "supported" types first, and just use libmagic for charset
+    const char *extension = get_extension(filename);
+    if (extension == NULL)
+        goto libmagic;
+    const char *supported = NULL;
+    for (unsigned int i = 0; content_types[i].extension != NULL; i++)
+        if (0 == strcmp(content_types[i].extension, extension))
+            supported = content_types[i].mimetype;
+    if (supported != NULL) {
+        newfd = dup(fd);
+        if (-1 != newfd) {
+            const char* charset = magic_descriptor(magic_charset, newfd);
+            close(newfd);
+            if (charset != NULL)
+                return sb_strdup_printf("%s; charset=%s", supported, charset);
+        }
+        return sb_strdup(supported);
+    }
+
+libmagic:
+
+    // fallback to use libmagic for everything
+    newfd = dup(fd);
+    if (-1 != newfd) {
+        const char* content_type = magic_descriptor(magic_all, newfd);
+        close(newfd);
+        if (content_type != NULL)
+            return sb_strdup(content_type);
+    }
+    return sb_strdup("application/octet-stream");
+}
+
+
+static void
+handler(struct evhttp_request *request, void *ptr)
+{
+    const char *root = ptr;
+    const char *uri = evhttp_request_get_uri(request);
+
+    struct evhttp_uri *decoded_uri = evhttp_uri_parse(uri);
+    if (decoded_uri == NULL) {
+        evhttp_send_error(request, 400, "Bad request");
+        return;
+    }
+
+    const char *path = evhttp_uri_get_path(decoded_uri);
+    if (path == NULL)
+        path = "/";
+
+    char *decoded_path = evhttp_uridecode(path, 0, NULL);
+    if (decoded_path == NULL) {
+        evhttp_send_error(request, 400, "Bad request");
+        goto point1;
+    }
+
+    char *abs_path = sb_strdup_printf("%s/%s", root, decoded_path);
+    char *real_path = realpath(abs_path, NULL);
+    free(abs_path);
+
+    if (real_path == NULL) {
+        evhttp_send_error(request, 404, "Not found");
+        goto point2;
+    }
+
+    char *real_root = realpath(root, NULL);
+    if (real_root == NULL) {
+        evhttp_send_error(request, 500, "Internal server error");
+        goto point3;
+    }
+
+    if (0 != strncmp(real_root, real_path, strlen(real_root))) {
+        evhttp_send_error(request, 404, "Not found");
+        goto point4;
+    }
+
+    struct stat st;
+    if (0 > stat(real_path, &st)) {
+        evhttp_send_error(request, 404, "Not found");
+        goto point4;
+    }
+
+    bool add_slash = false;
+
+    if (S_ISDIR(st.st_mode)) {
+        char *found = NULL;
+
+        for (unsigned int i = 0; content_types[i].mimetype != NULL; i++) {
+            if (content_types[i].index == NULL)
+                continue;
+            char *f = sb_strdup_printf("%s/%s", real_path,
+                content_types[i].index);
+            if (0 == access(f, F_OK)) {
+                found = sb_strdup(f);
+                break;
+            }
+            free(f);
+        }
+
+        if (found == NULL) {
+            evhttp_send_error(request, 403, "Forbidden");
+            goto point4;
+        }
+
+        size_t path_len = strlen(path);
+        if (path_len > 0 && path[path_len - 1] != '/')
+            add_slash = true;
+
+        free(real_path);
+        real_path = found;
+    }
+
+    int fd;
+    if ((fd = open(real_path, O_RDONLY)) < 0) {
+        evhttp_send_error(request, 500, "Internal server error");
+        goto point4;
+    }
+
+    char *type = guess_content_type(real_path, fd);
+
+    if (fstat(fd, &st) < 0) {
+        evhttp_send_error(request, 500, "Internal server error");
+        goto point5;
+    }
+
+    struct evkeyvalq *headers = evhttp_request_get_output_headers(request);
+
+    if (add_slash) {
+        char *tmp = sb_strdup_printf("%s/", path);
+        evhttp_add_header(headers, "Location", tmp);
+        free(tmp);
+        // production webservers usually returns 301 in such cases, but 302 is
+        // better for development/testing.
+        evhttp_send_reply(request, 302, "Found", NULL);
+        goto point5;
+    }
+
+    evhttp_add_header(headers, "Content-Type", type);
+    char *content_length = sb_strdup_printf("%zu", st.st_size);
+    evhttp_add_header(headers, "Content-Length", content_length);
+    free(content_length);
+
+    struct evbuffer *evb = evbuffer_new();
+    evbuffer_add_file(evb, fd, 0, st.st_size);
+    evhttp_send_reply(request, 200, "OK", evb);
+
+point5:
+    free(type);
+point4:
+    free(real_root);
+point3:
+    free(real_path);
+point2:
+    free(decoded_path);
+point1:
+    evhttp_uri_free(decoded_uri);
+}
+
+
+static int
+runserver(const char *address, unsigned short port, const char *root)
+{
+    struct event_base *base = event_base_new();
+    if (base == NULL) {
+        fprintf(stderr, "error: failed to initialize event base\n");
+        return 1;
+    }
+
+    struct evhttp *http = evhttp_new(base);
+    if (http == NULL) {
+        fprintf(stderr, "error: failed to initialize HTTP server\n");
+        return 1;
+    }
+
+    evhttp_set_gencb(http, handler, (char*) root);
+
+    evhttp_set_allowed_methods(http, EVHTTP_REQ_GET | EVHTTP_REQ_HEAD);
+
+    if (0 != evhttp_bind_socket(http, address, port)) {
+        fprintf(stderr, "error: failed to bind socket to %s:%d\n", address,
+            port);
+        return 1;
+    }
+
+    fprintf(stderr, " * Running on http://%s:%d/\n", address, port);
+
+    event_base_dispatch(base);
+
+    return 0;
+}
+
+
+static void
+print_help(void)
+{
+    printf(
+        "usage:\n"
+        "    blogc-runserver [-h] [-v] [-t HOST] [-p PORT] DOCROOT\n"
+        "                    - A simple HTTP server to test blogc websites.\n"
+        "\n"
+        "positional arguments:\n"
+        "    DOCROOT       document root directory\n"
+        "\n"
+        "optional arguments:\n"
+        "    -h            show this help message and exit\n"
+        "    -v            show version and exit\n"
+        "    -t HOST       set server listen address (default: 127.0.0.1)\n"
+        "    -p PORT       set server listen port (default: 8080)\n");
+}
+
+
+static void
+print_usage(void)
+{
+    printf("usage: blogc-runserver [-h] [-v] [-t HOST] [-p PORT] DOCROOT\n");
+}
+
+
+int
+main(int argc, char **argv)
+{
+    signal(SIGPIPE, SIG_IGN);
+
+    int rv = 0;
+    char *host = NULL;
+    char *docroot = NULL;
+    unsigned short port = 8080;
+
+    unsigned int args = 0;
+
+    for (unsigned int i = 1; i < argc; i++) {
+        if (argv[i][0] == '-') {
+            switch (argv[i][1]) {
+                case 'h':
+                    print_help();
+                    goto cleanup;
+                case 'v':
+                    printf("%s\n", PACKAGE_STRING);
+                    goto cleanup;
+                case 't':
+                    if (argv[i][2] != '\0')
+                        host = sb_strdup(argv[i] + 2);
+                    else
+                        host = sb_strdup(argv[++i]);
+                    break;
+                case 'p':
+                    if (argv[i][2] != '\0')
+                        port = strtoul(argv[i] + 2, NULL, 10);
+                    else
+                        port = strtoul(argv[++i], NULL, 10);
+                    break;
+                default:
+                    print_usage();
+                    fprintf(stderr, "blogc-runserver: error: invalid "
+                        "argument: -%c\n", argv[i][1]);
+                    rv = 2;
+                    goto cleanup;
+            }
+        }
+        else {
+            if (args > 0) {
+                print_usage();
+                fprintf(stderr, "blogc-runserver: error: only one positional "
+                    "argument allowed\n");
+                rv = 2;
+                goto cleanup;
+            }
+            args++;
+            docroot = sb_strdup(argv[i]);
+        }
+    }
+
+    if (docroot == NULL) {
+        print_usage();
+        fprintf(stderr, "blogc-runserver: error: document root directory "
+            "required\n");
+        rv = 2;
+        goto cleanup;
+    }
+
+    if (host == NULL)
+        host = sb_strdup("127.0.0.1");
+
+    magic_all = magic_open(MAGIC_MIME);
+    magic_charset = magic_open(MAGIC_MIME_ENCODING);
+    if (magic_all == NULL || magic_charset == NULL) {
+        fprintf(stderr, "error: failed to initialize libmagic\n");
+        rv = 1;
+        goto cleanup;
+    }
+
+    if ((0 != magic_load(magic_all, NULL)) ||
+        (0 != magic_load(magic_charset, NULL)))
+    {
+        fprintf(stderr, "error: failed to load libmagic data\n");
+        magic_close(magic_all);
+        magic_close(magic_charset);
+        rv = 1;
+        goto cleanup;
+    }
+
+    rv = runserver(host, port, docroot);
+
+    magic_close(magic_all);
+    magic_close(magic_charset);
+
+cleanup:
+    free(host);
+    free(docroot);
+
+    return rv;
+}