Mercurial > dovecot > core-2.2
view src/plugins/imap-acl/imap-acl-plugin.c @ 14682:d0d7b810646b
Make sure we check all the functions' return values. Minor API changes to simplify this.
Checked using a patched clang that adds attribute(warn_unused_result) to all
functions. This commit fixes several error handling mistakes.
author | Timo Sirainen <tss@iki.fi> |
---|---|
date | Mon, 25 Jun 2012 01:14:03 +0300 |
parents | 31119136ee6e |
children | 9ff19c1d5f69 |
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/* Copyright (c) 2008-2012 Dovecot authors, see the included COPYING file */ #include "imap-common.h" #include "str.h" #include "imap-quote.h" #include "imap-resp-code.h" #include "imap-commands.h" #include "mail-storage.h" #include "mail-namespace.h" #include "acl-api.h" #include "acl-storage.h" #include "acl-plugin.h" #include "imap-acl-plugin.h" #include <stdlib.h> #define ERROR_NOT_ADMIN "["IMAP_RESP_CODE_NOPERM"] " \ "You lack administrator privileges on this mailbox." #define IMAP_ACL_ANYONE "anyone" #define IMAP_ACL_AUTHENTICATED "authenticated" #define IMAP_ACL_OWNER "owner" #define IMAP_ACL_GROUP_PREFIX "$" #define IMAP_ACL_GROUP_OVERRIDE_PREFIX "!$" #define IMAP_ACL_GLOBAL_PREFIX "#" struct imap_acl_letter_map { char letter; const char *name; }; static const struct imap_acl_letter_map imap_acl_letter_map[] = { { 'l', MAIL_ACL_LOOKUP }, { 'r', MAIL_ACL_READ }, { 'w', MAIL_ACL_WRITE }, { 's', MAIL_ACL_WRITE_SEEN }, { 't', MAIL_ACL_WRITE_DELETED }, { 'i', MAIL_ACL_INSERT }, { 'p', MAIL_ACL_POST }, { 'e', MAIL_ACL_EXPUNGE }, { 'k', MAIL_ACL_CREATE }, { 'x', MAIL_ACL_DELETE }, { 'a', MAIL_ACL_ADMIN }, { '\0', NULL } }; const char *imap_acl_plugin_version = DOVECOT_VERSION; static struct module *imap_acl_module; static imap_client_created_func_t *next_hook_client_created; static struct mailbox * acl_mailbox_open_as_admin(struct client_command_context *cmd, const char *name) { struct mail_namespace *ns; struct mailbox *box; enum mailbox_existence existence = MAILBOX_EXISTENCE_NONE; int ret; if (ACL_USER_CONTEXT(cmd->client->user) == NULL) { client_send_command_error(cmd, "ACLs disabled."); return NULL; } ns = client_find_namespace(cmd, &name); if (ns == NULL) return NULL; /* Force opening the mailbox so that we can give a nicer error message if mailbox isn't selectable but is listable. */ box = mailbox_alloc(ns->list, name, MAILBOX_FLAG_READONLY | MAILBOX_FLAG_IGNORE_ACLS); if (mailbox_exists(box, TRUE, &existence) == 0 && existence == MAILBOX_EXISTENCE_SELECT) { ret = acl_mailbox_right_lookup(box, ACL_STORAGE_RIGHT_ADMIN); if (ret > 0) return box; } /* mailbox doesn't exist / not an administrator. */ if (existence != MAILBOX_EXISTENCE_SELECT || acl_mailbox_right_lookup(box, ACL_STORAGE_RIGHT_LOOKUP) <= 0) { client_send_tagline(cmd, t_strdup_printf( "NO ["IMAP_RESP_CODE_NONEXISTENT"] " MAIL_ERRSTR_MAILBOX_NOT_FOUND, name)); } else { client_send_tagline(cmd, "NO "ERROR_NOT_ADMIN); } mailbox_free(&box); return NULL; } static const struct imap_acl_letter_map * imap_acl_letter_map_find(const char *name) { unsigned int i; for (i = 0; imap_acl_letter_map[i].name != NULL; i++) { if (strcmp(imap_acl_letter_map[i].name, name) == 0) return &imap_acl_letter_map[i]; } return NULL; } static void imap_acl_write_rights_list(string_t *dest, const char *const *rights) { const struct imap_acl_letter_map *map; unsigned int i, orig_len = str_len(dest); bool append_c = FALSE, append_d = FALSE; for (i = 0; rights[i] != NULL; i++) { /* write only letters */ map = imap_acl_letter_map_find(rights[i]); if (map != NULL) { str_append_c(dest, map->letter); if (map->letter == 'k' || map->letter == 'x') append_c = TRUE; if (map->letter == 't' || map->letter == 'e') append_d = TRUE; } } if (append_c) str_append_c(dest, 'c'); if (append_d) str_append_c(dest, 'd'); if (orig_len == str_len(dest)) str_append(dest, "\"\""); } static void imap_acl_write_right(string_t *dest, string_t *tmp, const struct acl_rights *right, bool neg) { const char *const *rights = neg ? right->neg_rights : right->rights; str_truncate(tmp, 0); if (neg) str_append_c(tmp,'-'); if (right->global) str_append(tmp, IMAP_ACL_GLOBAL_PREFIX); switch (right->id_type) { case ACL_ID_ANYONE: str_append(tmp, IMAP_ACL_ANYONE); break; case ACL_ID_AUTHENTICATED: str_append(tmp, IMAP_ACL_AUTHENTICATED); break; case ACL_ID_OWNER: str_append(tmp, IMAP_ACL_OWNER); break; case ACL_ID_USER: str_append(tmp, right->identifier); break; case ACL_ID_GROUP: str_append(tmp, IMAP_ACL_GROUP_PREFIX); str_append(tmp, right->identifier); break; case ACL_ID_GROUP_OVERRIDE: str_append(tmp, IMAP_ACL_GROUP_OVERRIDE_PREFIX); str_append(tmp, right->identifier); break; case ACL_ID_TYPE_COUNT: i_unreached(); } imap_quote_append(dest, str_data(tmp), str_len(tmp), FALSE); str_append_c(dest, ' '); imap_acl_write_rights_list(dest, rights); } static bool acl_rights_is_owner(struct acl_backend *backend, const struct acl_rights *rights) { switch (rights->id_type) { case ACL_ID_OWNER: return TRUE; case ACL_ID_USER: return acl_backend_user_name_equals(backend, rights->identifier); default: return FALSE; } } static bool have_positive_owner_rights(struct acl_backend *backend, struct acl_object *aclobj) { struct acl_object_list_iter *iter; struct acl_rights rights; bool ret = FALSE; iter = acl_object_list_init(aclobj); while ((ret = acl_object_list_next(iter, &rights)) > 0) { if (acl_rights_is_owner(backend, &rights)) { if (rights.rights != NULL) { ret = TRUE; break; } } } acl_object_list_deinit(&iter); return ret; } static int imap_acl_write_aclobj(string_t *dest, struct acl_backend *backend, struct acl_object *aclobj, bool convert_owner, bool add_default) { struct acl_object_list_iter *iter; struct acl_rights rights; string_t *tmp; const char *username; unsigned int orig_len = str_len(dest); bool seen_owner = FALSE, seen_positive_owner = FALSE; int ret; username = acl_backend_get_acl_username(backend); if (username == NULL) convert_owner = FALSE; tmp = t_str_new(128); iter = acl_object_list_init(aclobj); while ((ret = acl_object_list_next(iter, &rights)) > 0) { if (acl_rights_is_owner(backend, &rights)) { if (rights.id_type == ACL_ID_OWNER && convert_owner) { rights.id_type = ACL_ID_USER; rights.identifier = username; } if (seen_owner && convert_owner) { /* oops, we have both owner and user=myself. can't do the conversion, so try again. */ str_truncate(dest, orig_len); return imap_acl_write_aclobj(dest, backend, aclobj, FALSE, add_default); } seen_owner = TRUE; if (rights.rights != NULL) seen_positive_owner = TRUE; } if (rights.rights != NULL) { str_append_c(dest, ' '); imap_acl_write_right(dest, tmp, &rights, FALSE); } if (rights.neg_rights != NULL) { str_append_c(dest, ' '); imap_acl_write_right(dest, tmp, &rights, TRUE); } } acl_object_list_deinit(&iter); if (!seen_positive_owner && username != NULL && add_default) { /* no positive owner rights returned, write default ACLs */ memset(&rights, 0, sizeof(rights)); if (!convert_owner) { rights.id_type = ACL_ID_OWNER; } else { rights.id_type = ACL_ID_USER; rights.identifier = username; } rights.rights = acl_object_get_default_rights(aclobj); if (rights.rights != NULL) { str_append_c(dest, ' '); imap_acl_write_right(dest, tmp, &rights, FALSE); } } return ret; } static bool cmd_getacl(struct client_command_context *cmd) { struct acl_backend *backend; struct mail_namespace *ns; struct mailbox *box; const char *mailbox; string_t *str; int ret; if (!client_read_string_args(cmd, 1, &mailbox)) return FALSE; box = acl_mailbox_open_as_admin(cmd, mailbox); if (box == NULL) return TRUE; str = t_str_new(128); str_append(str, "* ACL "); imap_quote_append_string(str, mailbox, FALSE); ns = mailbox_get_namespace(box); backend = acl_mailbox_list_get_backend(ns->list); ret = imap_acl_write_aclobj(str, backend, acl_mailbox_get_aclobj(box), TRUE, ns->type == NAMESPACE_PRIVATE); if (ret == 0) { client_send_line(cmd->client, str_c(str)); client_send_tagline(cmd, "OK Getacl completed."); } else { client_send_tagline(cmd, "NO "MAIL_ERRSTR_CRITICAL_MSG); } mailbox_free(&box); return TRUE; } static bool cmd_myrights(struct client_command_context *cmd) { struct mail_namespace *ns; struct mailbox *box; const char *mailbox; const char *const *rights; string_t *str; if (!client_read_string_args(cmd, 1, &mailbox)) return FALSE; if (ACL_USER_CONTEXT(cmd->client->user) == NULL) { client_send_command_error(cmd, "ACLs disabled."); return TRUE; } ns = client_find_namespace(cmd, &mailbox); if (ns == NULL) return TRUE; box = mailbox_alloc(ns->list, mailbox, MAILBOX_FLAG_READONLY | MAILBOX_FLAG_IGNORE_ACLS); if (acl_object_get_my_rights(acl_mailbox_get_aclobj(box), pool_datastack_create(), &rights) < 0) { client_send_tagline(cmd, "NO "MAIL_ERRSTR_CRITICAL_MSG); mailbox_free(&box); return TRUE; } /* Post right alone doesn't give permissions to see if the mailbox exists or not. Only mail deliveries care about that. */ if (*rights == NULL || (strcmp(*rights, MAIL_ACL_POST) == 0 && rights[1] == NULL)) { client_send_tagline(cmd, t_strdup_printf( "NO ["IMAP_RESP_CODE_NONEXISTENT"] " MAIL_ERRSTR_MAILBOX_NOT_FOUND, mailbox)); mailbox_free(&box); return TRUE; } str = t_str_new(128); str_append(str, "* MYRIGHTS "); imap_quote_append_string(str, mailbox, FALSE); str_append_c(str,' '); imap_acl_write_rights_list(str, rights); client_send_line(cmd->client, str_c(str)); client_send_tagline(cmd, "OK Myrights completed."); mailbox_free(&box); return TRUE; } static bool cmd_listrights(struct client_command_context *cmd) { struct mailbox *box; const char *mailbox, *identifier; string_t *str; if (!client_read_string_args(cmd, 2, &mailbox, &identifier)) return FALSE; box = acl_mailbox_open_as_admin(cmd, mailbox); if (box == NULL) return TRUE; str = t_str_new(128); str_append(str, "* LISTRIGHTS "); imap_quote_append_string(str, mailbox, FALSE); str_append_c(str, ' '); imap_quote_append_string(str, identifier, FALSE); str_append_c(str, ' '); str_append(str, "\"\" l r w s t p i e k x a c d"); client_send_line(cmd->client, str_c(str)); client_send_tagline(cmd, "OK Listrights completed."); mailbox_free(&box); return TRUE; } static int imap_acl_letters_parse(const char *letters, const char *const **rights_r, const char **error_r) { static const char *acl_k = MAIL_ACL_CREATE; static const char *acl_x = MAIL_ACL_DELETE; static const char *acl_e = MAIL_ACL_EXPUNGE; static const char *acl_t = MAIL_ACL_WRITE_DELETED; ARRAY_TYPE(const_string) rights; unsigned int i; t_array_init(&rights, 64); for (; *letters != '\0'; letters++) { for (i = 0; imap_acl_letter_map[i].name != NULL; i++) { if (imap_acl_letter_map[i].letter == *letters) { array_append(&rights, &imap_acl_letter_map[i].name, 1); break; } } if (imap_acl_letter_map[i].name == NULL) { /* Handling of obsolete rights as virtual rights according to RFC 4314 */ switch (*letters) { case 'c': array_append(&rights, &acl_k, 1); array_append(&rights, &acl_x, 1); break; case 'd': array_append(&rights, &acl_e, 1); array_append(&rights, &acl_t, 1); break; default: *error_r = t_strdup_printf( "Invalid ACL right: %c", *letters); return -1; } } } (void)array_append_space(&rights); *rights_r = array_idx(&rights, 0); return 0; } static bool acl_anyone_allow(struct mail_user *user) { const char *env; env = mail_user_plugin_getenv(user, "acl_anyone"); return env != NULL && strcmp(env, "allow") == 0; } static int imap_acl_identifier_parse(struct client_command_context *cmd, const char *id, struct acl_rights *rights, bool check_anyone, const char **error_r) { struct mail_user *user = cmd->client->user; if (strncmp(id, IMAP_ACL_GLOBAL_PREFIX, strlen(IMAP_ACL_GLOBAL_PREFIX)) == 0) { *error_r = t_strdup_printf("Global ACLs can't be modified: %s", id); return -1; } if (strcmp(id, IMAP_ACL_ANYONE) == 0) { if (check_anyone && !acl_anyone_allow(user)) { *error_r = "'anyone' identifier is disallowed"; return -1; } rights->id_type = ACL_ID_ANYONE; } else if (strcmp(id, IMAP_ACL_AUTHENTICATED) == 0) { if (check_anyone && !acl_anyone_allow(user)) { *error_r = "'authenticated' identifier is disallowed"; return -1; } rights->id_type = ACL_ID_AUTHENTICATED; } else if (strcmp(id, IMAP_ACL_OWNER) == 0) rights->id_type = ACL_ID_OWNER; else if (strncmp(id, IMAP_ACL_GROUP_PREFIX, strlen(IMAP_ACL_GROUP_PREFIX)) == 0) { rights->id_type = ACL_ID_GROUP; rights->identifier = id + strlen(IMAP_ACL_GROUP_PREFIX); } else if (strncmp(id, IMAP_ACL_GROUP_OVERRIDE_PREFIX, strlen(IMAP_ACL_GROUP_OVERRIDE_PREFIX)) == 0) { rights->id_type = ACL_ID_GROUP_OVERRIDE; rights->identifier = id + strlen(IMAP_ACL_GROUP_OVERRIDE_PREFIX); } else { rights->id_type = ACL_ID_USER; rights->identifier = id; } return 0; } static void imap_acl_update_ensure_keep_admins(struct acl_backend *backend, struct acl_object *aclobj, struct acl_rights_update *update) { static const char *acl_admin = MAIL_ACL_ADMIN; const char *const *rights = update->rights.rights; const char *const *default_rights; ARRAY_TYPE(const_string) new_rights; unsigned int i; t_array_init(&new_rights, 64); for (i = 0; rights[i] != NULL; i++) { if (strcmp(rights[i], MAIL_ACL_ADMIN) == 0) break; array_append(&new_rights, &rights[i], 1); } switch (update->modify_mode) { case ACL_MODIFY_MODE_ADD: if (have_positive_owner_rights(backend, aclobj)) return; /* adding initial rights for a user. we need to add the defaults also. don't worry about duplicates. */ for (; rights[i] != NULL; i++) array_append(&new_rights, &rights[i], 1); default_rights = acl_object_get_default_rights(aclobj); for (i = 0; default_rights[i] != NULL; i++) array_append(&new_rights, &default_rights[i], 1); break; case ACL_MODIFY_MODE_REMOVE: if (rights[i] == NULL) return; /* skip over the ADMIN removal and add the rest */ for (i++; rights[i] != NULL; i++) array_append(&new_rights, &rights[i], 1); break; case ACL_MODIFY_MODE_REPLACE: if (rights[i] != NULL) return; /* add the missing ADMIN right */ array_append(&new_rights, &acl_admin, 1); break; default: return; } (void)array_append_space(&new_rights); update->rights.rights = array_idx(&new_rights, 0); } static bool cmd_setacl(struct client_command_context *cmd) { struct mail_namespace *ns; struct mailbox *box; struct acl_backend *backend; struct acl_object *aclobj; struct acl_rights_update update; struct acl_rights *r; const char *mailbox, *identifier, *rights, *error; bool negative = FALSE; if (!client_read_string_args(cmd, 3, &mailbox, &identifier, &rights)) return FALSE; if (*identifier == '\0') { client_send_command_error(cmd, "Invalid arguments."); return TRUE; } memset(&update, 0, sizeof(update)); if (*identifier == '-') { negative = TRUE; identifier++; } switch (*rights) { case '-': update.modify_mode = ACL_MODIFY_MODE_REMOVE; rights++; break; case '+': update.modify_mode = ACL_MODIFY_MODE_ADD; rights++; break; default: update.modify_mode = ACL_MODIFY_MODE_REPLACE; break; } if (imap_acl_identifier_parse(cmd, identifier, &update.rights, TRUE, &error) < 0) { client_send_command_error(cmd, error); return TRUE; } if (imap_acl_letters_parse(rights, &update.rights.rights, &error) < 0) { client_send_command_error(cmd, error); return TRUE; } r = &update.rights; box = acl_mailbox_open_as_admin(cmd, mailbox); if (box == NULL) return TRUE; ns = mailbox_get_namespace(box); backend = acl_mailbox_list_get_backend(ns->list); if (ns->type == NAMESPACE_PUBLIC && r->id_type == ACL_ID_OWNER) { client_send_tagline(cmd, "NO Public namespaces have no owner"); mailbox_free(&box); return TRUE; } aclobj = acl_mailbox_get_aclobj(box); if (negative) { update.neg_modify_mode = update.modify_mode; update.modify_mode = ACL_MODIFY_MODE_REMOVE; update.rights.neg_rights = update.rights.rights; update.rights.rights = NULL; } else if (ns->type == NAMESPACE_PRIVATE && r->rights != NULL && ((r->id_type == ACL_ID_USER && acl_backend_user_name_equals(backend, r->identifier)) || (r->id_type == ACL_ID_OWNER && strcmp(acl_backend_get_acl_username(backend), ns->user->username) == 0))) { /* make sure client doesn't (accidentally) remove admin privileges from its own mailboxes */ imap_acl_update_ensure_keep_admins(backend, aclobj, &update); } if (acl_object_update(aclobj, &update) < 0) client_send_tagline(cmd, "NO "MAIL_ERRSTR_CRITICAL_MSG); else client_send_tagline(cmd, "OK Setacl complete."); mailbox_free(&box); return TRUE; } static bool cmd_deleteacl(struct client_command_context *cmd) { struct mailbox *box; struct acl_rights_update update; const char *mailbox, *identifier, *error; if (!client_read_string_args(cmd, 2, &mailbox, &identifier)) return FALSE; if (*identifier == '\0') { client_send_command_error(cmd, "Invalid arguments."); return TRUE; } memset(&update, 0, sizeof(update)); if (*identifier != '-') update.modify_mode = ACL_MODIFY_MODE_CLEAR; else { update.neg_modify_mode = ACL_MODIFY_MODE_CLEAR; identifier++; } if (imap_acl_identifier_parse(cmd, identifier, &update.rights, FALSE, &error) < 0) { client_send_command_error(cmd, error); return TRUE; } box = acl_mailbox_open_as_admin(cmd, mailbox); if (box == NULL) return TRUE; if (acl_object_update(acl_mailbox_get_aclobj(box), &update) < 0) client_send_tagline(cmd, "NO "MAIL_ERRSTR_CRITICAL_MSG); else client_send_tagline(cmd, "OK Deleteacl complete."); mailbox_free(&box); return TRUE; } static void imap_acl_client_created(struct client **client) { if (mail_user_is_plugin_loaded((*client)->user, imap_acl_module)) str_append((*client)->capability_string, " ACL RIGHTS=texk"); if (next_hook_client_created != NULL) next_hook_client_created(client); } void imap_acl_plugin_init(struct module *module) { command_register("LISTRIGHTS", cmd_listrights, 0); command_register("GETACL", cmd_getacl, 0); command_register("MYRIGHTS", cmd_myrights, 0); command_register("SETACL", cmd_setacl, 0); command_register("DELETEACL", cmd_deleteacl, 0); imap_acl_module = module; next_hook_client_created = imap_client_created_hook_set(imap_acl_client_created); } void imap_acl_plugin_deinit(void) { command_unregister("GETACL"); command_unregister("MYRIGHTS"); command_unregister("SETACL"); command_unregister("DELETEACL"); command_unregister("LISTRIGHTS"); (void)imap_client_created_hook_set(next_hook_client_created); } const char *imap_acl_plugin_dependencies[] = { "acl", NULL }; const char imap_acl_plugin_binary_dependency[] = "imap";