diff options
Diffstat (limited to 'client/kresc.c')
-rw-r--r-- | client/kresc.c | 471 |
1 files changed, 471 insertions, 0 deletions
diff --git a/client/kresc.c b/client/kresc.c new file mode 100644 index 0000000..42dba34 --- /dev/null +++ b/client/kresc.c @@ -0,0 +1,471 @@ +/* Copyright (C) 2016-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ +#include <arpa/inet.h> +#include <assert.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; +const 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; + } else { + free(cmd); + } + + if (starts_with(type, "[")) { + //Return "nil" on non-valid name. + free(type); + return "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 (str && 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)) { + printf("\n%s (%s)", token, get_type_name(token)); + 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) { + assert(false); + 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); + 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; +} |