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-rw-r--r--utils/client/kresc.c458
1 files changed, 458 insertions, 0 deletions
diff --git a/utils/client/kresc.c b/utils/client/kresc.c
new file mode 100644
index 0000000..16782a1
--- /dev/null
+++ b/utils/client/kresc.c
@@ -0,0 +1,458 @@
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+#include <arpa/inet.h>
+#include <contrib/ccan/asprintf/asprintf.h>
+#include <editline/readline.h>
+#include <errno.h>
+#include <histedit.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#define HISTORY_FILE "kresc_history"
+#define PROGRAM_NAME "kresc"
+
+FILE *g_tty = NULL; //!< connection to the daemon
+
+static char *run_cmd(const char *cmd, size_t * out_len);
+
+const char *prompt(EditLine * e)
+{
+ return PROGRAM_NAME "> ";
+}
+
+bool starts_with(const char *a, const char *b)
+{
+ if (strncmp(a, b, strlen(b)) == 0)
+ return 1;
+ return 0;
+}
+
+//! Returns Lua name of type of value, NULL on error. Puts length of type in name_len;
+char *get_type_name(const char *value)
+{
+ if (value == NULL) {
+ return NULL;
+ }
+
+ for (int i = 0; value[i]; i++) {
+ if (value[i] == ')') {
+ //Return NULL to prevent unexpected function call
+ return NULL;
+ }
+ }
+
+ char *cmd = afmt("type(%s)", value);
+ if (!cmd) {
+ perror("While tab-completing.");
+ return NULL;
+ }
+
+ size_t name_len;
+ char *type = run_cmd(cmd, &name_len);
+ if (!type) {
+ return NULL;
+ }
+ free(cmd);
+
+ if (starts_with(type, "[")) {
+ //Return "nil" on non-valid name.
+ free(type);
+ return strdup("nil");
+ } else {
+ type[strlen(type) - 1] = '\0';
+ return type;
+ }
+}
+
+static void complete_function(EditLine * el)
+{
+ //Add left parenthesis to function name.
+ el_insertstr(el, "(");
+}
+
+static void complete_members(EditLine * el, const char *str,
+ const char *str_type, int str_len, char *dot)
+{
+ char *table = strdup(str);
+ if (!table) {
+ perror("While tab-completing");
+ return;
+ }
+ //Get only the table name (without partial member name).
+ if (dot) {
+ *(table + (dot - str)) = '\0';
+ }
+ //Insert a dot after the table name.
+ if (!strncmp(str_type, "table", 5)) {
+ el_insertstr(el, ".");
+ str_len++;
+ }
+ //Check if the substring before dot is a valid table name.
+ const char *t_type = get_type_name(table);
+ if (t_type && !strncmp("table", t_type, 5)) {
+ //Get string of members of the table.
+ char *cmd =
+ afmt
+ ("do local s=\"\"; for i in pairs(%s) do s=s..i..\"\\n\" end return(s) end",
+ table);
+ if (!cmd) {
+ perror("While tab-completing.");
+ goto complete_members_exit;
+ }
+ size_t members_len;
+ char *members = run_cmd(cmd, &members_len);
+ free(cmd);
+ if (!members) {
+ perror("While communication with daemon");
+ goto complete_members_exit;
+ }
+ //Split members by newline.
+ char *members_tok = strdup(members);
+ free(members);
+ if (!members_tok) {
+ goto complete_members_exit;
+ }
+ char *token = strtok(members_tok, "\n");
+ int matches = 0;
+ char *lastmatch = NULL;
+ if (!dot || dot - str + 1 == strlen(str)) {
+ //Prints all members.
+ while (token) {
+ char *member = afmt("%s.%s", table, token);
+ const char *member_type = get_type_name(member);
+ if (member && member_type) {
+ printf("\n%s (%s)", member, member_type);
+ free(member);
+ free((void *)member_type);
+ } else if (member) {
+ printf("\n%s", member);
+ free(member);
+ }
+ token = strtok(NULL, "\n");
+ matches++;
+ }
+ } else {
+ //Print members matching the current line.
+ while (token) {
+ if (starts_with(token, dot + 1)) {
+ const char *member_type =
+ get_type_name(afmt
+ ("%s.%s", table,
+ token));
+ if (member_type) {
+ printf("\n%s.%s (%s)", table,
+ token, member_type);
+ free((void *)member_type);
+ } else {
+ printf("\n%s.%s", table, token);
+ }
+ lastmatch = token;
+ matches++;
+ }
+ token = strtok(NULL, "\n");
+ }
+
+ //Complete matching member.
+ if (matches == 1) {
+ el_deletestr(el, str_len);
+ el_insertstr(el, table);
+ el_insertstr(el, ".");
+ el_insertstr(el, lastmatch);
+ }
+ }
+ if (matches > 1) {
+ printf("\n");
+ }
+ free(members_tok);
+ }
+
+complete_members_exit:
+ free(table);
+ if(t_type) {
+ free((void*)t_type);
+ }
+}
+
+static void complete_globals(EditLine * el, const char *str, int str_len)
+{
+ //Parse Lua globals.
+ size_t globals_len;
+ char *globals = run_cmd("_G.__orig_name_list", &globals_len);
+ if (!globals) {
+ perror("While tab-completing");
+ return;
+ }
+ //Show possible globals.
+ char *globals_tok = strdup(globals);
+ free(globals);
+ if (!globals_tok) {
+ return;
+ }
+ char *token = strtok(globals_tok, "\n");
+ int matches = 0;
+ char *lastmatch = NULL;
+ while (token) {
+ if (str && starts_with(token, str)) {
+ char *name = get_type_name(token);
+ printf("\n%s (%s)", token, name);
+ free(name);
+ lastmatch = token;
+ matches++;
+ }
+ token = strtok(NULL, "\n");
+ }
+ if (matches > 1) {
+ printf("\n");
+ }
+ //Complete matching global.
+ if (matches == 1) {
+ el_deletestr(el, str_len);
+ el_insertstr(el, lastmatch);
+ }
+ free(globals_tok);
+}
+
+static unsigned char complete(EditLine * el, int ch)
+{
+ int argc, pos;
+ const char **argv;
+ const LineInfo *li = el_line(el);
+ Tokenizer *tok = tok_init(NULL);
+
+ //Tokenize current line.
+ int ret = tok_line(tok, li, &argc, &argv, NULL, &pos);
+
+ if (ret != 0) {
+ perror("While tab-completing.");
+ goto complete_exit;
+ }
+ //Show help.
+ if (argc == 0) {
+ size_t help_len;
+ char *help = run_cmd("help()", &help_len);
+ if (help) {
+ printf("\n%s", help);
+ free(help);
+ } else {
+ perror("While communication with daemon");
+ }
+ goto complete_exit;
+ }
+
+ if (argc > 1) {
+ goto complete_exit;
+ }
+ //Get name of type of current line.
+ const char *type = get_type_name(argv[0]);
+
+ if (!type) {
+ goto complete_exit;
+ }
+ //Get position of last dot in current line (useful for parsing table).
+ char *dot = strrchr(argv[0], '.');
+
+ if (strncmp(type, "table", 5) != 0 && !dot) {
+ //Line is not a name of some table and there is no dot in it.
+ complete_globals(el, argv[0], pos);
+ } else if ((dot && strncmp(type, "nil", 3) == 0)
+ || strncmp(type, "table", 5) == 0) {
+ //Current line (or part of it) is a name of some table.
+ complete_members(el, argv[0], type, pos, dot);
+ } else if (strncmp(type, "function", 8) == 0) {
+ //Current line is a function.
+ complete_function(el);
+ }
+ if (type) {
+ free((void *)type);
+ }
+
+complete_exit:
+ tok_reset(tok);
+ tok_end(tok);
+ return CC_REDISPLAY;
+}
+
+//! Initialize connection to the daemon; return 0 on success.
+static int init_tty(const char *path)
+{
+ int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (fd < 0)
+ return 1;
+
+ struct sockaddr_un addr;
+ addr.sun_family = AF_UNIX;
+ size_t plen = strlen(path);
+ if (plen + 1 > sizeof(addr.sun_path)) {
+ fprintf(stderr, "Path too long\n");
+ close(fd);
+ return 1;
+ }
+ memcpy(addr.sun_path, path, plen + 1);
+ if (connect(fd, (const struct sockaddr *)&addr, sizeof(addr))) {
+ perror("While connecting to daemon");
+ close(fd);
+ return 1;
+ }
+ g_tty = fdopen(fd, "r+");
+ if (!g_tty) {
+ perror("While opening TTY");
+ close(fd);
+ return 1;
+ }
+
+ // Switch to binary mode and consume the text "> ".
+ if (fprintf(g_tty, "__binary\n") < 0 || !fread(&addr, 2, 1, g_tty)
+ || fflush(g_tty)) {
+ perror("While initializing TTY");
+ fclose(g_tty);
+ g_tty = NULL;
+ return 1;
+ }
+
+ return 0;
+}
+
+//! Run a command on the daemon; return the answer or NULL on failure, puts answer length to out_len.
+static char *run_cmd(const char *cmd, size_t * out_len)
+{
+ if (!g_tty || !cmd)
+ return NULL;
+ if (fprintf(g_tty, "%s", cmd) < 0 || fflush(g_tty))
+ return NULL;
+ uint32_t len;
+ if (!fread(&len, sizeof(len), 1, g_tty))
+ return NULL;
+ len = ntohl(len);
+ if (!len)
+ return NULL;
+ char *msg = malloc(1 + (size_t) len);
+ if (!msg)
+ return NULL;
+ if (len && !fread(msg, len, 1, g_tty)) {
+ free(msg);
+ return NULL;
+ }
+ msg[len] = '\0';
+ *out_len = len;
+ return msg;
+}
+
+static int interact()
+{
+ EditLine *el;
+ History *hist;
+ int count;
+ const char *line;
+ HistEvent ev;
+ el = el_init(PROGRAM_NAME, stdin, stdout, stderr);
+ el_set(el, EL_PROMPT, prompt);
+ el_set(el, EL_EDITOR, "emacs");
+ el_set(el, EL_ADDFN, PROGRAM_NAME "-complete",
+ "Perform " PROGRAM_NAME " completion.", complete);
+ el_set(el, EL_BIND, "^I", PROGRAM_NAME "-complete", NULL);
+
+ hist = history_init();
+ if (hist == 0) {
+ perror("While initializing command history");
+ return 1;
+ }
+ history(hist, &ev, H_SETSIZE, 800);
+ el_set(el, EL_HIST, history, hist);
+
+ char *hist_file = NULL;
+
+ char *data_home = getenv("XDG_DATA_HOME");
+
+ //Check whether $XDG_DATA_HOME is set.
+ if (!data_home || *data_home == '\0') {
+ const char *home = getenv("HOME"); //This should be set on any POSIX compliant OS, even for nobody
+
+ //Create necessary folders.
+ char *dirs[3] =
+ { afmt("%s/.local", home), afmt("%s/.local/share", home),
+ afmt("%s/.local/share/knot-resolver/", home)
+ };
+ bool ok = true;
+ for (int i = 0; i < 3; i++) {
+ if (mkdir(dirs[i], 0755) && errno != EEXIST) {
+ ok = false;
+ break;
+ }
+ }
+ if (ok) {
+ hist_file =
+ afmt("%s/.local/share/knot-resolver/" HISTORY_FILE, home);
+ }
+ } else {
+ if (!mkdir(afmt("%s/knot-resolver/", data_home), 0755)
+ || errno == EEXIST) {
+ hist_file = afmt("%s/knot-resolver/" HISTORY_FILE, data_home);
+ }
+ }
+
+ //Load history file
+ if (hist_file) {
+ history(hist, &ev, H_LOAD, hist_file);
+ } else {
+ perror("While opening history file");
+ }
+
+ while (1) {
+ line = el_gets(el, &count);
+ if (count > 0) {
+ history(hist, &ev, H_ENTER, line);
+ size_t msg_len;
+ char *msg = run_cmd(line, &msg_len);
+ if (!msg) {
+ perror("While communication with daemon");
+ history_end(hist);
+ el_end(el);
+ free(msg);
+ return 1;
+ }
+ printf("%s", msg);
+ if (msg_len > 0 && msg[msg_len - 1] != '\n') {
+ printf("\n");
+ }
+ if (hist_file) {
+ history(hist, &ev, H_SAVE, hist_file);
+ }
+ free(msg);
+ }
+ }
+ history_end(hist);
+ free(hist_file);
+ el_end(el);
+ if (feof(stdin))
+ return 0;
+ perror("While reading input");
+ return 1;
+}
+
+int main(int argc, char **argv)
+{
+ fprintf(stderr, "Warning! %s is highly experimental, use at own risk.\n", argv[0]);
+ fprintf(stderr, "Please tell authors what features you expect from client utility.\n");
+ if (argc != 2) {
+ fprintf(stderr, "Usage: %s tty/xxxxx\n", argv[0]);
+ return 1;
+ }
+
+ int res = init_tty(argv[1]);
+
+ if (!res)
+ res = interact();
+
+ if (g_tty)
+ fclose(g_tty);
+ return res;
+}
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