diff options
Diffstat (limited to 'assuan/assuan-handler.c')
| -rw-r--r-- | assuan/assuan-handler.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/assuan/assuan-handler.c b/assuan/assuan-handler.c new file mode 100644 index 00000000..472206b0 --- /dev/null +++ b/assuan/assuan-handler.c @@ -0,0 +1,431 @@ +/* assuan-handler.c - dispatch commands + * Copyright (C) 2001 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG 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 2 of the License, or + * (at your option) any later version. + * + * GnuPG 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, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include <config.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +#include "assuan-defs.h" + +#define digitp(a) ((a) >= '0' && (a) <= '9') + + +static int +dummy_handler (ASSUAN_CONTEXT ctx, char *line) +{ + return set_error (ctx, Server_Fault, "no handler registered"); +} + + +static int +std_handler_nop (ASSUAN_CONTEXT ctx, char *line) +{ + return 0; /* okay */ +} + +static int +std_handler_cancel (ASSUAN_CONTEXT ctx, char *line) +{ + return set_error (ctx, Not_Implemented, NULL); +} + +static int +std_handler_bye (ASSUAN_CONTEXT ctx, char *line) +{ + return -1; /* pretty simple :-) */ +} + +static int +std_handler_auth (ASSUAN_CONTEXT ctx, char *line) +{ + return set_error (ctx, Not_Implemented, NULL); +} + +static int +std_handler_reset (ASSUAN_CONTEXT ctx, char *line) +{ + return set_error (ctx, Not_Implemented, NULL); +} + +static int +std_handler_end (ASSUAN_CONTEXT ctx, char *line) +{ + return set_error (ctx, Not_Implemented, NULL); +} + +static int +parse_cmd_input_output (ASSUAN_CONTEXT ctx, char *line, int *rfd) +{ + char *endp; + + if (strncmp (line, "FD=", 3)) + return set_error (ctx, Syntax_Error, "FD=<n> expected"); + line += 3; + if (!digitp (*line)) + return set_error (ctx, Syntax_Error, "number required"); + *rfd = strtoul (line, &endp, 10); + if (*endp) + return set_error (ctx, Syntax_Error, "garbage found"); + if (*rfd == ctx->inbound.fd) + return set_error (ctx, Parameter_Conflict, "fd same as inbound fd"); + if (*rfd == ctx->outbound.fd) + return set_error (ctx, Parameter_Conflict, "fd same as outbound fd"); + return 0; +} + +/* Format is INPUT FD=<n> */ +static int +std_handler_input (ASSUAN_CONTEXT ctx, char *line) +{ + int rc, fd; + + rc = parse_cmd_input_output (ctx, line, &fd); + if (rc) + return rc; + ctx->input_fd = fd; + return 0; +} + +/* Format is OUTPUT FD=<n> */ +static int +std_handler_output (ASSUAN_CONTEXT ctx, char *line) +{ + int rc, fd; + + rc = parse_cmd_input_output (ctx, line, &fd); + if (rc) + return rc; + ctx->output_fd = fd; + return 0; +} + + + + + +/* This is a table with the standard commands and handler for them. + The table is used to initialize a new context and assuciate strings + and handlers with cmd_ids */ +static struct { + const char *name; + int cmd_id; + int (*handler)(ASSUAN_CONTEXT, char *line); + int always; /* always initializethis command */ +} std_cmd_table[] = { + { "NOP", ASSUAN_CMD_NOP, std_handler_nop, 1 }, + { "CANCEL", ASSUAN_CMD_CANCEL, std_handler_cancel, 1 }, + { "BYE", ASSUAN_CMD_BYE, std_handler_bye, 1 }, + { "AUTH", ASSUAN_CMD_AUTH, std_handler_auth, 1 }, + { "RESET", ASSUAN_CMD_RESET, std_handler_reset, 1 }, + { "END", ASSUAN_CMD_END, std_handler_end, 1 }, + + { "INPUT", ASSUAN_CMD_INPUT, std_handler_input }, + { "OUTPUT", ASSUAN_CMD_OUTPUT, std_handler_output }, + { NULL } +}; + + +/** + * assuan_register_command: + * @ctx: the server context + * @cmd_id: An ID value for the command + * @cmd_name: A string with the command name + * @handler: The handler function to be called + * + * Register a handler to be used for a given command. + * + * The @cmd_name must be %NULL or an empty string for all @cmd_ids + * below %ASSUAN_CMD_USER because predefined values are used. + * + * Return value: + **/ +int +assuan_register_command (ASSUAN_CONTEXT ctx, + int cmd_id, const char *cmd_name, + int (*handler)(ASSUAN_CONTEXT, char *)) +{ + int i; + + if (cmd_name && !*cmd_name) + cmd_name = NULL; + + if (cmd_id < ASSUAN_CMD_USER) + { + if (cmd_name) + return ASSUAN_Invalid_Value; /* must be NULL for these values*/ + + for (i=0; std_cmd_table[i].name; i++) + { + if (std_cmd_table[i].cmd_id == cmd_id) + { + cmd_name = std_cmd_table[i].name; + if (!handler) + handler = std_cmd_table[i].handler; + break; + } + } + if (!std_cmd_table[i].name) + return ASSUAN_Invalid_Value; /* not a pre-registered one */ + } + + if (!handler) + handler = dummy_handler; + + if (!cmd_name) + return ASSUAN_Invalid_Value; + +/* fprintf (stderr, "DBG-assuan: registering %d as `%s'\n", cmd_id, cmd_name); */ + + if (!ctx->cmdtbl) + { + ctx->cmdtbl_size = 50; + ctx->cmdtbl = xtrycalloc ( ctx->cmdtbl_size, sizeof *ctx->cmdtbl); + if (!ctx->cmdtbl) + return ASSUAN_Out_Of_Core; + ctx->cmdtbl_used = 0; + } + else if (ctx->cmdtbl_used >= ctx->cmdtbl_size) + { + struct cmdtbl_s *x; + + x = xtryrealloc ( ctx->cmdtbl, (ctx->cmdtbl_size+10) * sizeof *x); + if (!x) + return ASSUAN_Out_Of_Core; + ctx->cmdtbl = x; + ctx->cmdtbl_size += 50; + } + + ctx->cmdtbl[ctx->cmdtbl_used].name = cmd_name; + ctx->cmdtbl[ctx->cmdtbl_used].cmd_id = cmd_id; + ctx->cmdtbl[ctx->cmdtbl_used].handler = handler; + ctx->cmdtbl_used++; + return 0; +} + +/* Helper to register the standards commands */ +int +_assuan_register_std_commands (ASSUAN_CONTEXT ctx) +{ + int i, rc; + + for (i=0; std_cmd_table[i].name; i++) + { + if (std_cmd_table[i].always) + { + rc = assuan_register_command (ctx, std_cmd_table[i].cmd_id, + NULL, NULL); + if (rc) + return rc; + } + } + return 0; +} + + + +/* Process the special data lines. The "D " has already been removed + from the line. As all handlers this function may modify the line. */ +static int +handle_data_line (ASSUAN_CONTEXT ctx, char *line, int linelen) +{ + return set_error (ctx, Not_Implemented, NULL); +} + + +/* Parse the line, break out the command, find it in the command + table, remove leading and white spaces from the arguments, all the + handler with the argument line and return the error */ +static int +dispatch_command (ASSUAN_CONTEXT ctx, char *line, int linelen) +{ + char *p; + const char *s; + int shift, i; + + if (*line == 'D' && line[1] == ' ') /* divert to special handler */ + return handle_data_line (ctx, line+2, linelen-2); + + for (p=line; *p && *p != ' ' && *p != '\t'; p++) + ; + if (p==line) + return set_error (ctx, Invalid_Command, "leading white-space"); + if (*p) + { /* Skip over leading WS after the keyword */ + *p++ = 0; + while ( *p == ' ' || *p == '\t') + p++; + } + shift = p - line; + + for (i=0; (s=ctx->cmdtbl[i].name); i++) + if (!strcmp (line, s)) + break; + if (!s) + return set_error (ctx, Unknown_Command, NULL); + line += shift; + linelen -= shift; + +/* fprintf (stderr, "DBG-assuan: processing %s `%s'\n", s, line); */ + return ctx->cmdtbl[i].handler (ctx, line); +} + + + + +/** + * assuan_process: + * @ctx: assuan context + * + * This fucntion is used to handle the assuan protocol after a + * connection has been established using assuan_accept(). This is the + * main protocol handler. + * + * Return value: 0 on success or an error code if the assuan operation + * failed. Note, that no error is returned for operational errors. + **/ +int +assuan_process (ASSUAN_CONTEXT ctx) +{ + int rc; + + do { + /* Read the line but skip comments */ + do + { + rc = _assuan_read_line (ctx); + if (rc) + return rc; + +/* fprintf (stderr, "DBG-assuan: got %d bytes `%s'\n", */ +/* ctx->inbound.linelen, ctx->inbound.line); */ + } + while ( *ctx->inbound.line == '#' || !ctx->inbound.linelen); + + ctx->outbound.data.error = 0; + ctx->outbound.data.linelen = 0; + /* dispatch command and return reply */ + rc = dispatch_command (ctx, ctx->inbound.line, ctx->inbound.linelen); + /* check from data write errors */ + if (ctx->outbound.data.fp) + { /* Flush the data lines */ + fclose (ctx->outbound.data.fp); + ctx->outbound.data.fp = NULL; + if (!rc && ctx->outbound.data.error) + rc = ctx->outbound.data.error; + } + /* Error handling */ + if (!rc) + { + rc = _assuan_write_line (ctx, "OK"); + } + else if (rc == -1) + { /* No error checking because the peer may have already disconnect */ + _assuan_write_line (ctx, "OK Bye, bye - hope to meet you again"); + } + else + { + char errline[256]; + + if (rc < 100) + sprintf (errline, "ERR %d server fault (%.50s)", + ASSUAN_Server_Fault, assuan_strerror (rc)); + else + { + const char *text = ctx->err_no == rc? ctx->err_str:NULL; + + sprintf (errline, "ERR %d %.50s%s%.100s", + rc, assuan_strerror (rc), text? " - ":"", text?text:""); + } + rc = _assuan_write_line (ctx, errline); + } + } while (!rc); + + if (rc == -1) + rc = 0; + + return rc; +} + + +/* Return a FP to be used for data output. The FILE pointer is valid + until the end of a handler. So a close is not needed. Assuan does + all the buffering needed to insert the status line as well as the + required line wappping and quoting for data lines. + + We use GNU's custom streams here. There should be an alternative + implementaion for systems w/o a glibc, a simple implementation + could use a child process */ +FILE * +assuan_get_data_fp (ASSUAN_CONTEXT ctx) +{ + cookie_io_functions_t cookie_fnc; + + if (ctx->outbound.data.fp) + return ctx->outbound.data.fp; + + cookie_fnc.read = NULL; + cookie_fnc.write = _assuan_cookie_write_data; + cookie_fnc.seek = NULL; + cookie_fnc.close = _assuan_cookie_write_flush; + + ctx->outbound.data.fp = fopencookie (ctx, "wb", cookie_fnc); + ctx->outbound.data.error = 0; + return ctx->outbound.data.fp; +} + + +void +assuan_write_status (ASSUAN_CONTEXT ctx, const char *keyword, const char *text) +{ + char buffer[256]; + char *helpbuf; + size_t n; + + if ( !ctx || !keyword) + return; + if (!text) + text = ""; + + n = 2 + strlen (keyword) + 1 + strlen (text) + 1; + if (n < sizeof (buffer)) + { + strcpy (buffer, "S "); + strcat (buffer, keyword); + if (*text) + { + strcat (buffer, " "); + strcat (buffer, text); + } + _assuan_write_line (ctx, buffer); + } + else if ( (helpbuf = xtrymalloc (n)) ) + { + strcpy (helpbuf, "S "); + strcat (helpbuf, keyword); + if (*text) + { + strcat (helpbuf, " "); + strcat (helpbuf, text); + } + _assuan_write_line (ctx, helpbuf); + xfree (helpbuf); + } +} |