diff options
Diffstat (limited to 'src/vfs/sftpfs/config_parser.c')
| -rw-r--r-- | src/vfs/sftpfs/config_parser.c | 425 |
1 files changed, 425 insertions, 0 deletions
diff --git a/src/vfs/sftpfs/config_parser.c b/src/vfs/sftpfs/config_parser.c new file mode 100644 index 0000000..4292b5d --- /dev/null +++ b/src/vfs/sftpfs/config_parser.c @@ -0,0 +1,425 @@ +/* Virtual File System: SFTP file system. + The SSH config parser + + Copyright (C) 2011-2022 + Free Software Foundation, Inc. + + Written by: + Ilia Maslakov <il.smind@gmail.com>, 2011 + Slava Zanko <slavazanko@gmail.com>, 2011, 2012, 2013 + + This file is part of the Midnight Commander. + + The Midnight Commander 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. + + The Midnight Commander 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 <http://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <errno.h> +#include <stddef.h> +#include <stdlib.h> /* atoi() */ + +#include "lib/global.h" + +#include "lib/search.h" +#include "lib/util.h" /* tilde_expand() */ +#include "lib/vfs/utilvfs.h" + +#include "internal.h" + +/*** global variables ****************************************************************************/ + +/*** file scope macro definitions ****************************************************************/ + +#define SFTP_DEFAULT_PORT 22 + +#ifndef SFTPFS_SSH_CONFIG +#define SFTPFS_SSH_CONFIG "~/.ssh/config" +#endif + +/*** file scope type declarations ****************************************************************/ + +typedef struct +{ + char *real_host; /* host DNS name or ip address */ + int port; /* port for connect to host */ + char *user; /* the user to log in as */ + gboolean password_auth; /* FALSE - no passwords allowed (default TRUE) */ + gboolean identities_only; /* TRUE - no ssh agent (default FALSE) */ + gboolean pubkey_auth; /* FALSE - disable public key authentication (default TRUE) */ + char *identity_file; /* A file from which the user's DSA, ECDSA or DSA authentication identity is read. */ +} sftpfs_ssh_config_entity_t; + +enum config_var_type +{ + STRING, + INTEGER, + BOOLEAN, + FILENAME +}; + +/*** file scope variables ************************************************************************/ + +/* *INDENT-OFF* */ +static struct +{ + const char *pattern; + mc_search_t *pattern_regexp; + enum config_var_type type; + size_t offset; +} config_variables[] = +{ + {"^\\s*User\\s+(.*)$", NULL, STRING, offsetof (sftpfs_ssh_config_entity_t, user)}, + {"^\\s*HostName\\s+(.*)$", NULL, STRING, offsetof (sftpfs_ssh_config_entity_t, real_host)}, + {"^\\s*IdentitiesOnly\\s+(.*)$", NULL, BOOLEAN, offsetof (sftpfs_ssh_config_entity_t, identities_only)}, + {"^\\s*IdentityFile\\s+(.*)$", NULL, FILENAME, offsetof (sftpfs_ssh_config_entity_t, identity_file)}, + {"^\\s*Port\\s+(.*)$", NULL, INTEGER, offsetof (sftpfs_ssh_config_entity_t, port)}, + {"^\\s*PasswordAuthentication\\s+(.*)$", NULL, BOOLEAN, offsetof (sftpfs_ssh_config_entity_t, password_auth)}, + {"^\\s*PubkeyAuthentication\\s+(.*)$", NULL, STRING, offsetof (sftpfs_ssh_config_entity_t, pubkey_auth)}, + {NULL, NULL, 0, 0} +}; +/* *INDENT-ON* */ + +/* --------------------------------------------------------------------------------------------- */ +/*** file scope functions ************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ +/** + * Free one config entity. + * + * @param config_entity config entity structure + */ + +static void +sftpfs_ssh_config_entity_free (sftpfs_ssh_config_entity_t * config_entity) +{ + g_free (config_entity->real_host); + g_free (config_entity->user); + g_free (config_entity->identity_file); + g_free (config_entity); +} + +/* --------------------------------------------------------------------------------------------- */ +/** + * Transform tilda (~) to full home dirname. + * + * @param filename file name with tilda + * @return newly allocated file name with full home dirname + */ + +static char * +sftpfs_correct_file_name (const char *filename) +{ + vfs_path_t *vpath; + char *fn; + + fn = tilde_expand (filename); + vpath = vfs_path_from_str (fn); + g_free (fn); + return vfs_path_free (vpath, FALSE); +} + +/* --------------------------------------------------------------------------------------------- */ + +#define POINTER_TO_STRUCTURE_MEMBER(type) \ + ((type) ((char *) config_entity + (size_t) config_variables[i].offset)) + +/** + * Parse string and filling one config entity by parsed data. + * + * @param config_entity config entity structure + * @param buffer string for parce + */ + +static void +sftpfs_fill_config_entity_from_string (sftpfs_ssh_config_entity_t * config_entity, char *buffer) +{ + int i; + + for (i = 0; config_variables[i].pattern != NULL; i++) + { + if (mc_search_run (config_variables[i].pattern_regexp, buffer, 0, strlen (buffer), NULL)) + { + int value_offset; + char *value; + + int *pointer_int; + char **pointer_str; + gboolean *pointer_bool; + + /* Calculate start of value in string */ + value_offset = mc_search_getstart_result_by_num (config_variables[i].pattern_regexp, 1); + value = &buffer[value_offset]; + + switch (config_variables[i].type) + { + case STRING: + pointer_str = POINTER_TO_STRUCTURE_MEMBER (char **); + *pointer_str = g_strdup (value); + break; + case FILENAME: + pointer_str = POINTER_TO_STRUCTURE_MEMBER (char **); + *pointer_str = sftpfs_correct_file_name (value); + break; + case INTEGER: + pointer_int = POINTER_TO_STRUCTURE_MEMBER (int *); + *pointer_int = atoi (value); + break; + case BOOLEAN: + pointer_bool = POINTER_TO_STRUCTURE_MEMBER (gboolean *); + *pointer_bool = strcasecmp (value, "True") == 0; + break; + default: + continue; + } + return; + } + } +} + +#undef POINTER_TO_STRUCTURE_MEMBER + +/* --------------------------------------------------------------------------------------------- */ +/** + * Fill one config entity from config file. + * + * @param ssh_config_handler file descriptor for the ssh config file + * @param config_entity config entity structure + * @param vpath_element path element with host data (hostname, port) + * @param mcerror pointer to the error handler + * @return TRUE if config entity was filled successfully, FALSE otherwise + */ + +static gboolean +sftpfs_fill_config_entity_from_config (FILE * ssh_config_handler, + sftpfs_ssh_config_entity_t * config_entity, + const vfs_path_element_t * vpath_element, GError ** mcerror) +{ + char buffer[BUF_MEDIUM]; + gboolean host_block_hit = FALSE; + gboolean pattern_block_hit = FALSE; + mc_search_t *host_regexp; + gboolean ok = TRUE; + + mc_return_val_if_error (mcerror, FALSE); + + host_regexp = mc_search_new ("^\\s*host\\s+(.*)$", DEFAULT_CHARSET); + host_regexp->search_type = MC_SEARCH_T_REGEX; + host_regexp->is_case_sensitive = FALSE; + + while (TRUE) + { + char *cr; + + if (fgets (buffer, sizeof (buffer), ssh_config_handler) == NULL) + { + int e; + + e = errno; + + if (!feof (ssh_config_handler)) + { + mc_propagate_error (mcerror, e, + _("sftp: an error occurred while reading %s: %s"), + SFTPFS_SSH_CONFIG, strerror (e)); + ok = FALSE; + goto done; + } + + break; + } + + cr = strrchr (buffer, '\n'); + if (cr != NULL) + *cr = '\0'; + + if (mc_search_run (host_regexp, buffer, 0, strlen (buffer), NULL)) + { + const char *host_pattern; + int host_pattern_offset; + + /* if previous host block exactly describe our connection */ + if (host_block_hit) + goto done; + + host_pattern_offset = mc_search_getstart_result_by_num (host_regexp, 1); + host_pattern = &buffer[host_pattern_offset]; + if (strcmp (host_pattern, vpath_element->host) == 0) + { + /* current host block describe our connection */ + host_block_hit = TRUE; + } + else + { + mc_search_t *pattern_regexp; + + pattern_regexp = mc_search_new (host_pattern, DEFAULT_CHARSET); + pattern_regexp->search_type = MC_SEARCH_T_GLOB; + pattern_regexp->is_case_sensitive = FALSE; + pattern_regexp->is_entire_line = TRUE; + pattern_block_hit = + mc_search_run (pattern_regexp, vpath_element->host, 0, + strlen (vpath_element->host), NULL); + mc_search_free (pattern_regexp); + } + } + else if (pattern_block_hit || host_block_hit) + { + sftpfs_fill_config_entity_from_string (config_entity, buffer); + } + } + + done: + mc_search_free (host_regexp); + return ok; +} + +/* --------------------------------------------------------------------------------------------- */ +/** + * Open the ssh config file and fill config entity. + * + * @param vpath_element path element with host data (hostname, port) + * @param mcerror pointer to the error handler + * @return newly allocated config entity structure + */ + +static sftpfs_ssh_config_entity_t * +sftpfs_get_config_entity (const vfs_path_element_t * vpath_element, GError ** mcerror) +{ + sftpfs_ssh_config_entity_t *config_entity; + FILE *ssh_config_handler; + char *config_filename; + + mc_return_val_if_error (mcerror, FALSE); + + config_entity = g_new0 (sftpfs_ssh_config_entity_t, 1); + config_entity->password_auth = TRUE; + config_entity->identities_only = FALSE; + config_entity->pubkey_auth = TRUE; + config_entity->port = SFTP_DEFAULT_PORT; + + config_filename = sftpfs_correct_file_name (SFTPFS_SSH_CONFIG); + ssh_config_handler = fopen (config_filename, "r"); + g_free (config_filename); + + if (ssh_config_handler != NULL) + { + gboolean ok; + + ok = sftpfs_fill_config_entity_from_config + (ssh_config_handler, config_entity, vpath_element, mcerror); + fclose (ssh_config_handler); + + if (!ok) + { + sftpfs_ssh_config_entity_free (config_entity); + return NULL; + } + } + + if (config_entity->user == NULL) + { + config_entity->user = vfs_get_local_username (); + if (config_entity->user == NULL) + { + sftpfs_ssh_config_entity_free (config_entity); + config_entity = NULL; + mc_propagate_error (mcerror, EPERM, "%s", _("sftp: Unable to get current user name.")); + } + } + return config_entity; +} + +/* --------------------------------------------------------------------------------------------- */ +/*** public functions ****************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ +/** + * Reads data from the ssh config file related to connection. + * + * @param super connection data + * @param error pointer to the error handler + */ + +void +sftpfs_fill_connection_data_from_config (struct vfs_s_super *super, GError ** mcerror) +{ + sftpfs_super_t *sftpfs_super = SFTP_SUPER (super); + sftpfs_ssh_config_entity_t *config_entity; + + mc_return_if_error (mcerror); + + config_entity = sftpfs_get_config_entity (super->path_element, mcerror); + if (config_entity == NULL) + return; + + sftpfs_super->config_auth_type = (config_entity->pubkey_auth) ? PUBKEY : 0; + sftpfs_super->config_auth_type |= (config_entity->identities_only) ? 0 : AGENT; + sftpfs_super->config_auth_type |= (config_entity->password_auth) ? PASSWORD : 0; + + if (super->path_element->port == 0) + super->path_element->port = config_entity->port; + + if (super->path_element->user == NULL) + super->path_element->user = g_strdup (config_entity->user); + + if (config_entity->real_host != NULL) + { + g_free (super->path_element->host); + super->path_element->host = g_strdup (config_entity->real_host); + } + + if (config_entity->identity_file != NULL) + { + sftpfs_super->privkey = g_strdup (config_entity->identity_file); + sftpfs_super->pubkey = g_strdup_printf ("%s.pub", config_entity->identity_file); + } + + sftpfs_ssh_config_entity_free (config_entity); +} + +/* --------------------------------------------------------------------------------------------- */ +/** + * Initialize the SSH config parser. + */ + +void +sftpfs_init_config_variables_patterns (void) +{ + int i; + + for (i = 0; config_variables[i].pattern != NULL; i++) + { + config_variables[i].pattern_regexp = + mc_search_new (config_variables[i].pattern, DEFAULT_CHARSET); + config_variables[i].pattern_regexp->search_type = MC_SEARCH_T_REGEX; + config_variables[i].pattern_regexp->is_case_sensitive = FALSE; + } +} + +/* --------------------------------------------------------------------------------------------- */ +/** + * Deinitialize the SSH config parser. + */ + +void +sftpfs_deinit_config_variables_patterns (void) +{ + int i; + + for (i = 0; config_variables[i].pattern != NULL; i++) + { + mc_search_free (config_variables[i].pattern_regexp); + config_variables[i].pattern_regexp = NULL; + } +} + +/* --------------------------------------------------------------------------------------------- */ |