git-receiver: splitted/reimplemented and tested shell command parser

1 files changed, 125 insertions, 0 deletions

diff --git a/src/blogc-git-receiver/shell-command-parser.c b/src/blogc-git-receiver/shell-command-parser.c
new file mode 100644
index 0000000..cc8c537
--- /dev/null
+++ b/src/blogc-git-receiver/shell-command-parser.c
@@ -0,0 +1,125 @@
+/*
+ * 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.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "../common/utils.h"
+#include "shell-command-parser.h"
+
+typedef enum {
+    START_COMMAND = 1,
+    START_REPO,
+    START_REPO2,
+    REPO,
+    START_ESCAPED,
+} command_state_t;
+
+
+char*
+bgr_shell_command_parse(const char *command)
+{
+    command_state_t state = START_COMMAND;
+    size_t start = 0;
+    size_t command_len = strlen(command);
+
+    bc_string_t *rv = bc_string_new();
+
+    for (size_t current = 0; current < command_len; current++) {
+
+        char c = command[current];
+
+        switch (state) {
+            case START_COMMAND:
+                if (c == ' ') {
+                    if (((current == 16) &&
+                         (0 == strncmp("git-receive-pack", command, 16))) ||
+                        ((current == 15) &&
+                         (0 == strncmp("git-upload-pack", command, 15))) ||
+                        ((current == 18) &&
+                         (0 == strncmp("git-upload-archive", command, 18))))
+                    {
+                        state = START_REPO;
+                        break;
+                    }
+                    goto error;
+                }
+                break;
+
+            case START_REPO:
+                if (c == '\'') {  // never saw git using double-quotes
+                    state = START_REPO2;
+                    break;
+                }
+                if (c == '\\') {  // escaped ! or '
+                    state = START_ESCAPED;
+                    break;
+                }
+                goto error;
+
+            case START_REPO2:
+                if (c == '\'') {
+                    state = START_REPO;
+                    break;
+                }
+                start = current;
+                if (rv->len == 0 && c == '/') {  // no absolute urls
+                    start = current + 1;
+                }
+                state = REPO;
+                break;
+
+            case START_ESCAPED:
+                if (c == '!' || c == '\'') {
+                    bc_string_append_c(rv, c);
+                    state = START_REPO;
+                    break;
+                }
+                goto error;
+
+            case REPO:
+                if (c == '\'') {
+                    bc_string_append_len(rv, command + start, current - start);
+                    state = START_REPO;
+                    break;
+                }
+                break;
+        }
+    }
+
+    if (rv->len > 0)
+        return bc_string_free(rv, false);
+
+error:
+    bc_string_free(rv, true);
+    return NULL;
+}
+
+
+char*
+bgr_shell_quote(const char *command)
+{
+    // this does not really belongs here, but function is very small
+    bc_string_t *rv = bc_string_new();
+    bc_string_append_c(rv, '\'');
+    if (command != NULL) {
+        for (size_t i = 0; i < strlen(command); i++) {
+            switch (command[i]) {
+                case '!':
+                    bc_string_append(rv, "'\\!'");
+                    break;
+                case '\'':
+                    bc_string_append(rv, "'\\''");
+                    break;
+                default:
+                    bc_string_append_c(rv, command[i]);
+            }
+        }
+    }
+    bc_string_append_c(rv, '\'');
+    return bc_string_free(rv, false);
+}