blogc-git-receiver: import external tool to blogc repository

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

the tool is build by default, if needed headers are found. that means
that it will probably only be built for posix-compliant operating
systems.

6 files changed, 589 insertions, 16 deletions

diff --git a/.gitignore b/.gitignore
index 48f0735..911360f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,8 +44,9 @@ Makefile.in
 /blogc*.[17]
 blogc*.html
 
-# blogc
+# binaries
 /blogc
+/blogc-git-receiver
 
 # tests
 /tests/check_content_parser
diff --git a/Makefile.am b/Makefile.am
index 8237508..934e1cc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -6,6 +6,7 @@ AM_DISTCHECK_CONFIGURE_FLAGS = \
 	--enable-tests \
 	--enable-ronn \
 	--disable-valgrind \
+	--enable-git-receiver \
 	$(NULL)
 
 
@@ -43,6 +44,7 @@ noinst_HEADERS = \
 
 noinst_LTLIBRARIES = \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 noinst_PROGRAMS = \
@@ -52,6 +54,12 @@ bin_PROGRAMS = \
 	blogc \
 	$(NULL)
 
+if BUILD_GIT_RECEIVER
+bin_PROGRAMS += \
+	blogc-git-receiver \
+	$(NULL)
+endif
+
 check_PROGRAMS = \
 	$(NULL)
 
@@ -65,7 +73,6 @@ libblogc_la_SOURCES = \
 	src/renderer.c \
 	src/source-parser.c \
 	src/template-parser.c \
-	src/utils.c \
 	$(NULL)
 
 libblogc_la_CFLAGS = \
@@ -78,8 +85,18 @@ libblogc_la_LIBADD = \
 	$(NULL)
 
 
+libblogc_utils_la_SOURCES = \
+	src/utils.c \
+	$(NULL)
+
+libblogc_utils_la_CFLAGS = \
+	$(AM_CFLAGS) \
+	-I$(top_srcdir)/src \
+	$(NULL)
+
+
 blogc_SOURCES = \
-	src/main.c \
+	src/blogc.c \
 	$(NULL)
 
 blogc_CFLAGS = \
@@ -89,9 +106,26 @@ blogc_CFLAGS = \
 
 blogc_LDADD = \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 
+if BUILD_GIT_RECEIVER
+blogc_git_receiver_SOURCES = \
+	src/blogc-git-receiver.c \
+	$(NULL)
+
+blogc_git_receiver_CFLAGS = \
+	$(AM_CFLAGS) \
+	-I$(top_srcdir)/src \
+	$(NULL)
+
+blogc_git_receiver_LDADD = \
+	libblogc_utils.la \
+	$(NULL)
+endif
+
+
 ## Build rules: man pages
 
 EXTRA_DIST += \
@@ -107,6 +141,14 @@ dist_man_MANS = \
 	blogc-template.7 \
 	$(NULL)
 
+if BUILD_GIT_RECEIVER
+EXTRA_DIST += \
+	$(NULL)
+
+dist_man_MANS += \
+	$(NULL)
+endif
+
 MAINTAINERCLEANFILES += \
 	$(dist_man_MANS) \
 	$(NULL)
@@ -181,6 +223,7 @@ tests_check_error_LDFLAGS = \
 tests_check_error_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_loader_SOURCES = \
@@ -200,6 +243,7 @@ tests_check_loader_LDFLAGS = \
 tests_check_loader_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_content_parser_SOURCES = \
@@ -217,6 +261,7 @@ tests_check_content_parser_LDFLAGS = \
 tests_check_content_parser_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_datetime_parser_SOURCES = \
@@ -234,6 +279,7 @@ tests_check_datetime_parser_LDFLAGS = \
 tests_check_datetime_parser_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_renderer_SOURCES = \
@@ -251,6 +297,7 @@ tests_check_renderer_LDFLAGS = \
 tests_check_renderer_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_source_parser_SOURCES = \
@@ -268,6 +315,7 @@ tests_check_source_parser_LDFLAGS = \
 tests_check_source_parser_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_template_parser_SOURCES = \
@@ -285,6 +333,7 @@ tests_check_template_parser_LDFLAGS = \
 tests_check_template_parser_LDADD = \
 	$(CMOCKA_LIBS) \
 	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 tests_check_utils_SOURCES = \
@@ -301,7 +350,7 @@ tests_check_utils_LDFLAGS = \
 
 tests_check_utils_LDADD = \
 	$(CMOCKA_LIBS) \
-	libblogc.la \
+	libblogc_utils.la \
 	$(NULL)
 
 endif
diff --git a/build-aux/travis-build.sh b/build-aux/travis-build.sh
index 1fcac10..4187575 100755
--- a/build-aux/travis-build.sh
+++ b/build-aux/travis-build.sh
@@ -13,9 +13,10 @@ if [[ "x${TARGET}" = xw* ]]; then
     export CHOST="x86_64-w64-mingw32"
     [[ "x${TARGET}" = "xw32" ]] && export CHOST="i686-w64-mingw32"
     MAKE_TARGET="all"
+    CONFIGURE_ARGS="--disable-git-receiver"
 else
     export CFLAGS="-Wall -g"
-    export CONFIGURE_ARGS="--enable-tests --enable-valgrind"
+    CONFIGURE_ARGS="--enable-tests --enable-valgrind"
 fi
 
 pushd build > /dev/null
diff --git a/configure.ac b/configure.ac
index 1e7366e..858db59 100644
--- a/configure.ac
+++ b/configure.ac
@@ -119,6 +119,24 @@ AS_IF([test "x$have_cmocka" = "xyes"], , [
 ])
 AM_CONDITIONAL([USE_CMOCKA], [test "x$have_cmocka" = "xyes"])
 
+GIT_RECEIVER="disabled"
+AC_ARG_ENABLE([git-receiver], AS_HELP_STRING([--disable-git-receiver],
+              [disable blogc-git-receiver build]))
+AS_IF([test "x$enable_git_receiver" != "xno"], [
+  AC_CHECK_HEADERS([sys/types.h sys/stat.h time.h libgen.h unistd.h errno.h dirent.h], [
+    GIT_RECEIVER="enabled"
+    have_git_receiver=yes
+  ], [
+    have_git_receiver=no
+  ])
+])
+AS_IF([test "x$have_git_receiver" = "xyes"], , [
+  AS_IF([test "x$enable_git_receiver" = "xyes"], [
+    AC_MSG_ERROR([blogc-git-receiver requested but required headers not found])
+  ])
+])
+AM_CONDITIONAL([BUILD_GIT_RECEIVER], [test "x$have_git_receiver" = "xyes"])
+
 AC_CHECK_HEADERS([sys/types.h sys/stat.h time.h])
 
 LT_LIB_M
@@ -131,19 +149,21 @@ AC_CONFIG_FILES([
 AC_OUTPUT
 
 AS_ECHO("
-        ==== ${PACKAGE_STRING} ====
+        ====== ${PACKAGE_STRING} ======
+
+        prefix:              ${prefix}
+        exec_prefix:         ${exec_prefix}
+        bindir:              ${bindir}
 
-        prefix:       ${prefix}
-        exec_prefix:  ${exec_prefix}
-        bindir:       ${bindir}
+        compiler:            ${CC}
+        cflags:              ${CFLAGS}
+        ldflags:             ${LDFLAGS}
 
-        compiler:     ${CC}
-        cflags:       ${CFLAGS}
-        ldflags:      ${LDFLAGS}
+        blogc-git-receiver:  ${GIT_RECEIVER}
 
-        tests:        ${TESTS}
+        tests:               ${TESTS}
 
-        ronn:         ${RONN}
-        valgrind:     ${VALGRIND}
-        rpmbuild:     ${RPMBUILD}
+        ronn:                ${RONN}
+        valgrind:            ${VALGRIND}
+        rpmbuild:            ${RPMBUILD}
 ")
diff --git a/src/blogc-git-receiver.c b/src/blogc-git-receiver.c
new file mode 100644
index 0000000..ffeac61
--- /dev/null
+++ b/src/blogc-git-receiver.c
@@ -0,0 +1,502 @@
+/*
+ * 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 <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <libgen.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <time.h>
+
+#include "utils.h"
+
+#ifndef BUFFER_SIZE
+#define BUFFER_SIZE 4096
+#endif
+
+
+static unsigned int
+cpu_count(void)
+{
+#ifdef _SC_NPROCESSORS_ONLN
+    long num = sysconf(_SC_NPROCESSORS_ONLN);
+    if (num >= 1)
+        return (unsigned int) num;
+#endif
+    return 1;
+}
+
+
+static void
+rmdir_recursive(const char *dir)
+{
+    struct stat buf;
+    if (0 != stat(dir, &buf)) {
+        fprintf(stderr, "warning: failed to remove directory (%s): %s\n", dir,
+            strerror(errno));
+        return;
+    }
+    if (!S_ISDIR(buf.st_mode)) {
+        fprintf(stderr, "error: trying to remove invalid directory: %s\n", dir);
+        exit(2);
+    }
+    DIR *d = opendir(dir);
+    if (d == NULL) {
+        fprintf(stderr, "error: failed to open directory: %s\n",
+            strerror(errno));
+        exit(2);
+    }
+    struct dirent *e;
+    while (NULL != (e = readdir(d))) {
+        if ((0 == strcmp(e->d_name, ".")) || (0 == strcmp(e->d_name, "..")))
+            continue;
+        char *f = sb_strdup_printf("%s/%s", dir, e->d_name);
+        if (0 != stat(f, &buf)) {
+            fprintf(stderr, "error: failed to stat directory entry (%s): %s\n",
+                e->d_name, strerror(errno));
+            free(f);
+            exit(2);
+        }
+        if (S_ISDIR(buf.st_mode)) {
+            rmdir_recursive(f);
+        }
+        else if (0 != unlink(f)) {
+            fprintf(stderr, "error: failed to remove file (%s): %s\n", f,
+                strerror(errno));
+            free(f);
+            exit(2);
+        }
+        free(f);
+    }
+    if (0 != closedir(d)) {
+        fprintf(stderr, "error: failed to close directory: %s\n",
+            strerror(errno));
+        exit(2);
+    }
+    if (0 != rmdir(dir)) {
+        fprintf(stderr, "error: failed to remove directory: %s\n",
+            strerror(errno));
+        exit(2);
+    }
+}
+
+
+static int
+git_shell(int argc, char *argv[])
+{
+    int rv = 0;
+
+    char *repo = NULL;
+    char *command_orig = NULL;
+    char *command_name = NULL;
+    char command_new[BUFFER_SIZE];
+
+    bool exec_git = false;
+
+    // validate git command
+    size_t len = strlen(argv[2]);
+    if (!((len > 17 && (0 == strncmp(argv[2], "git-receive-pack ", 17))) ||
+          (len > 16 && (0 == strncmp(argv[2], "git-upload-pack ", 16))) ||
+          (len > 19 && (0 == strncmp(argv[2], "git-upload-archive ", 19)))))
+    {
+        fprintf(stderr, "error: unsupported git command: %s\n", argv[2]);
+        rv = 1;
+        goto cleanup;
+    }
+
+    // get shell path
+    char *self = getenv("SHELL");
+    if (self == NULL) {
+        fprintf(stderr, "error: failed to find blogc-git-receiver path\n");
+        rv = 1;
+        goto cleanup;
+    }
+
+    // get home path
+    char *home = getenv("HOME");
+    if (home == NULL) {
+        fprintf(stderr, "error: failed to find user home path\n");
+        rv = 1;
+        goto cleanup;
+    }
+
+    // get git repository
+    command_orig = sb_strdup(argv[2]);
+    char *p, *r;
+    for (p = command_orig; *p != ' ' && *p != '\0'; p++);
+    if (*p == ' ')
+        p++;
+    if (*p == '\'' || *p == '"')
+        p++;
+    if (*p == '/')
+        p++;
+    for (r = p; *p != '\'' && *p != '"' && *p != '\0'; p++);
+    if (*p == '\'' || *p == '"')
+        *p = '\0';
+    if (*--p == '/')
+        *p = '\0';
+
+    repo = sb_strdup_printf("repos/%s", r);
+
+    // check if repository is sane
+    if (0 == strlen(repo)) {
+        fprintf(stderr, "error: invalid repository\n");
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (0 == strncmp(argv[2], "git-upload-", 11))  // no need to check len here
+        goto git_exec;
+
+    if (0 != chdir(home)) {
+        fprintf(stderr, "error: failed to chdir (%s): %s\n", home,
+            strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (0 != access(repo, F_OK)) {
+        char *git_init_cmd = sb_strdup_printf(
+            "git init --bare \"%s\" > /dev/null", repo);
+        if (0 != system(git_init_cmd)) {
+            fprintf(stderr, "error: failed to create git repository: %s\n",
+                repo);
+            rv = 1;
+            free(git_init_cmd);
+            goto cleanup;
+        }
+        free(git_init_cmd);
+    }
+
+    if (0 != chdir(repo)) {
+        fprintf(stderr, "error: failed to chdir (%s/%s): %s\n", home, repo,
+            strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (0 != access("hooks", F_OK)) {
+        // openwrt git package won't install git templates, then the git
+        // repositories created with it won't have the hooks/ directory.
+        if (0 != mkdir("hooks", 0777)) {  // mkdir honors umask for us.
+            fprintf(stderr, "error: failed to create directory (%s/%s/hooks): "
+                "%s\n", home, repo, strerror(errno));
+            rv = 1;
+            goto cleanup;
+        }
+    }
+
+    if (0 != chdir("hooks")) {
+        fprintf(stderr, "error: failed to chdir (%s/%s/hooks): %s\n", home,
+            repo, strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (0 == access("pre-receive", F_OK)) {
+        if (0 != unlink("pre-receive")) {
+            fprintf(stderr, "error: failed to remove old symlink "
+                "(%s/%s/hooks/pre-receive): %s\n", home, repo, strerror(errno));
+            rv = 1;
+            goto cleanup;
+        }
+    }
+
+    if (0 != symlink(self, "pre-receive")) {
+        fprintf(stderr, "error: failed to create symlink "
+            "(%s/%s/hooks/pre-receive): %s\n", home, repo, strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (0 == access("post-receive", F_OK)) {
+        if (0 != unlink("post-receive")) {
+            fprintf(stderr, "error: failed to remove old symlink "
+                "(%s/%s/hooks/post-receive): %s\n", home, repo, strerror(errno));
+            rv = 1;
+            goto cleanup;
+        }
+    }
+
+    if (0 != symlink(self, "post-receive")) {
+        fprintf(stderr, "error: failed to create symlink "
+            "(%s/%s/hooks/post-receive): %s\n", home, repo, strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (0 != chdir(home)) {
+        fprintf(stderr, "error: failed to chdir (%s): %s\n", home,
+            strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+git_exec:
+    command_name = sb_strdup(argv[2]);
+    for (p = command_name; *p != ' ' && *p != '\0'; p++);
+    if (*p == ' ')
+        *p = '\0';
+
+    if (BUFFER_SIZE < (strlen(command_name) + strlen(repo) + 4)) {
+        fprintf(stderr, "error: git-shell command is too big\n");
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (snprintf(command_new, BUFFER_SIZE, "%s '%s'", command_name, repo))
+        exec_git = true;
+
+cleanup:
+    free(repo);
+    free(command_orig);
+    free(command_name);
+
+    if (exec_git) {
+        execlp("git-shell", "git-shell", "-c", command_new, NULL);
+
+        // execlp only returns on error, then something bad happened
+        fprintf(stderr, "error: failed to execute git-shell\n");
+        rv = 1;
+    }
+
+    return rv;
+}
+
+
+static int
+git_post_receive_hook(int argc, char *argv[])
+{
+    if (0 != system("git remote get-url --push mirror &> /dev/null"))
+        return 0;
+
+    // at this point we know that we have a remote called mirror, we can just
+    // push to it.
+    if (0 != system("git push --mirror mirror"))
+        fprintf(stderr, "warning: failed push to git mirror\n");
+
+    return 0;
+}
+
+
+typedef enum {
+    START_OLD = 1,
+    OLD,
+    START_NEW,
+    NEW,
+    START_REF,
+    REF
+} input_state_t;
+
+
+static int
+git_pre_receive_hook(int argc, char *argv[])
+{
+    int c;
+    char buffer[BUFFER_SIZE];
+
+    input_state_t state = START_OLD;
+    size_t i = 0;
+    size_t start = 0;
+
+    int rv = 0;
+    char *new = NULL;
+    char *master = NULL;
+
+    while (EOF != (c = getc(stdin))) {
+
+        buffer[i] = (char) c;
+
+        switch (state) {
+            case START_OLD:
+                start = i;
+                state = OLD;
+                break;
+            case OLD:
+                if (c != ' ')
+                    break;
+                // no need to store old
+                state = START_NEW;
+                break;
+            case START_NEW:
+                start = i;
+                state = NEW;
+                break;
+            case NEW:
+                if (c != ' ')
+                    break;
+                state = START_REF;
+                new = strndup(buffer + start, i - start);
+                break;
+            case START_REF:
+                start = i;
+                state = REF;
+                break;
+            case REF:
+                if (c != '\n')
+                    break;
+                state = START_OLD;
+                // we just care about a ref (refs/heads/master), everything
+                // else is disposable :)
+                if (!((i - start == 17) &&
+                      (0 == strncmp("refs/heads/master", buffer + start, 17))))
+                {
+                    free(new);
+                    new = NULL;
+                    break;
+                }
+                master = new;
+                break;
+        }
+
+        if (++i >= BUFFER_SIZE) {
+            fprintf(stderr, "error: pre-receive hook payload is too big.\n");
+            rv = 1;
+            goto cleanup2;
+        }
+    }
+
+    if (master == NULL) {
+        fprintf(stderr, "warning: no reference to master branch found. "
+            "nothing to deploy.\n");
+        goto cleanup2;
+    }
+
+    char *repo_dir = NULL;
+    char *output_dir = NULL;
+
+    if (NULL == getcwd(buffer, BUFFER_SIZE)) {
+        fprintf(stderr, "error: failed to get repository remote path: %s\n",
+            strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    repo_dir = sb_strdup(buffer);
+
+    char dir[] = "/tmp/blogc_XXXXXX";
+    if (NULL == mkdtemp(dir)) {
+        rv = 1;
+        goto cleanup;
+    }
+
+    char *git_archive_cmd = sb_strdup_printf(
+        "git archive \"%s\" | tar -x -C \"%s\" -f -", master, dir);
+    if (0 != system(git_archive_cmd)) {
+        fprintf(stderr, "error: failed to extract git content to temporary "
+            "directory: %s\n", dir);
+        rv = 1;
+        free(git_archive_cmd);
+        goto cleanup;
+    }
+    free(git_archive_cmd);
+
+    if (0 != chdir(dir)) {
+        fprintf(stderr, "error: failed to chdir (%s): %s\n", dir,
+            strerror(errno));
+        rv = 1;
+        goto cleanup;
+    }
+
+    if ((0 != access("Makefile", F_OK)) && (0 != access("GNUMakefile", F_OK))) {
+        fprintf(stderr, "warning: no makefile found. skipping ...\n");
+        goto cleanup;
+    }
+
+    char *home = getenv("HOME");
+    if (home == NULL) {
+        fprintf(stderr, "error: failed to find user home path\n");
+        rv = 1;
+        goto cleanup;
+    }
+
+    unsigned long epoch = time(NULL);
+    output_dir = sb_strdup_printf("%s/builds/%s-%lu", home, master, epoch);
+    char *gmake_cmd = sb_strdup_printf(
+        "gmake -j%d OUTPUT_DIR=\"%s\" BLOGC_GIT_RECEIVER=1",
+        cpu_count(), output_dir);
+    fprintf(stdout, "running command: %s\n\n", gmake_cmd);
+    fflush(stdout);
+    if (0 != system(gmake_cmd)) {
+        fprintf(stderr, "error: failed to build website ...\n");
+        rmdir_recursive(output_dir);
+        free(gmake_cmd);
+        rv = 1;
+        goto cleanup;
+    }
+    free(gmake_cmd);
+
+    if (0 != chdir(repo_dir)) {
+        fprintf(stderr, "error: failed to chdir (%s): %s\n", repo_dir,
+            strerror(errno));
+        rmdir_recursive(output_dir);
+        rv = 1;
+        goto cleanup;
+    }
+
+    char *htdocs_sym = NULL;
+    ssize_t htdocs_sym_len = readlink("htdocs", buffer, BUFFER_SIZE);
+    if (0 < htdocs_sym_len) {
+        if (0 != unlink("htdocs")) {
+            fprintf(stderr, "error: failed to remove symlink (%s/htdocs): %s\n",
+                repo_dir, strerror(errno));
+            rmdir_recursive(output_dir);
+            rv = 1;
+            goto cleanup;
+        }
+        buffer[htdocs_sym_len] = '\0';
+        htdocs_sym = buffer;
+    }
+
+    if (0 != symlink(output_dir, "htdocs")) {
+        fprintf(stderr, "error: failed to create symlink (%s/htdocs): %s\n",
+            repo_dir, strerror(errno));
+        rmdir_recursive(output_dir);
+        rv = 1;
+        goto cleanup;
+    }
+
+    if (htdocs_sym != NULL)
+        rmdir_recursive(htdocs_sym);
+
+cleanup:
+    free(output_dir);
+    rmdir_recursive(dir);
+    free(repo_dir);
+cleanup2:
+    free(new);
+    return rv;
+}
+
+
+int
+main(int argc, char *argv[])
+{
+    if (argc > 0) {
+        if (0 == strcmp(basename(argv[0]), "pre-receive"))
+            return git_pre_receive_hook(argc, argv);
+        if (0 == strcmp(basename(argv[0]), "post-receive"))
+            return git_post_receive_hook(argc, argv);
+    }
+
+    if (argc == 3 && (0 == strcmp(argv[1], "-c")))
+        return git_shell(argc, argv);
+
+    fprintf(stderr, "error: this is a special shell, go away!\n");
+    return 1;
+}
diff --git a/src/main.c b/src/blogc.c
index 2338c9e..2338c9e 100644
--- a/src/main.c
+++ b/src/blogc.c