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Diffstat (limited to 'src/db.h')
| -rw-r--r-- | src/db.h | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/src/db.h b/src/db.h new file mode 100644 index 0000000..765c607 --- /dev/null +++ b/src/db.h @@ -0,0 +1,217 @@ +/** + * Enhanced Seccomp Filter DB + * + * Copyright (c) 2012,2016 Red Hat <pmoore@redhat.com> + * Author: Paul Moore <paul@paul-moore.com> + */ + +/* + * This library is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License as + * published by the Free Software Foundation. + * + * This library 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 Lesser General Public License + * for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this library; if not, see <http://www.gnu.org/licenses>. + */ + +#ifndef _FILTER_DB_H +#define _FILTER_DB_H + +#include <inttypes.h> +#include <stdbool.h> + +#include <seccomp.h> + +#include "arch.h" + +/* XXX - need to provide doxygen comments for the types here */ + +struct db_api_arg { + unsigned int arg; + enum scmp_compare op; + scmp_datum_t mask; + scmp_datum_t datum; + + bool valid; +}; + +struct db_api_rule_list { + uint32_t action; + int syscall; + bool strict; + struct db_api_arg args[ARG_COUNT_MAX]; + + struct db_api_rule_list *prev, *next; +}; + +struct db_arg_chain_tree { + /* argument number (a0 = 0, a1 = 1, etc.) */ + unsigned int arg; + /* true to indicate this is the high 32-bit word of a 64-bit value */ + bool arg_h_flg; + /* argument bpf offset */ + unsigned int arg_offset; + + /* comparison operator */ + enum scmp_compare op; + enum scmp_compare op_orig; + /* syscall argument value */ + uint32_t mask; + uint32_t datum; + scmp_datum_t datum_full; + + /* actions */ + bool act_t_flg; + bool act_f_flg; + uint32_t act_t; + uint32_t act_f; + + /* list of nodes on this level */ + struct db_arg_chain_tree *lvl_prv, *lvl_nxt; + + /* next node in the chain */ + struct db_arg_chain_tree *nxt_t; + struct db_arg_chain_tree *nxt_f; + + unsigned int refcnt; +}; +#define ARG_MASK_MAX ((uint32_t)-1) + +struct db_sys_list { + /* native syscall number */ + unsigned int num; + + /* priority - higher is better */ + unsigned int priority; + + /* the argument chain heads */ + struct db_arg_chain_tree *chains; + unsigned int node_cnt; + + /* action in the case of no argument chains */ + uint32_t action; + + struct db_sys_list *next; + /* temporary use only by the BPF generator */ + struct db_sys_list *pri_prv, *pri_nxt; + + bool valid; +}; + +struct db_filter_attr { + /* action to take if we don't match an explicit allow/deny */ + uint32_t act_default; + /* action to take if we don't match the architecture */ + uint32_t act_badarch; + /* NO_NEW_PRIVS related attributes */ + uint32_t nnp_enable; + /* SECCOMP_FILTER_FLAG_TSYNC related attributes */ + uint32_t tsync_enable; + /* allow rules with a -1 syscall value */ + uint32_t api_tskip; + /* SECCOMP_FILTER_FLAG_LOG related attributes */ + uint32_t log_enable; + /* SPEC_ALLOW related attributes */ + uint32_t spec_allow; + /* SCMP_FLTATR_CTL_OPTIMIZE related attributes */ + uint32_t optimize; + /* return the raw system return codes */ + uint32_t api_sysrawrc; +}; + +struct db_filter { + /* target architecture */ + const struct arch_def *arch; + + /* syscall filters, kept as a sorted single-linked list */ + struct db_sys_list *syscalls; + unsigned int syscall_cnt; + + /* list of rules used to build the filters, kept in order */ + struct db_api_rule_list *rules; +}; + +struct db_filter_snap { + /* individual filters */ + struct db_filter **filters; + unsigned int filter_cnt; + bool shadow; + + struct db_filter_snap *next; +}; + +struct db_filter_col { + /* verification / state */ + int state; + + /* attributes */ + struct db_filter_attr attr; + + /* individual filters */ + int endian; + struct db_filter **filters; + unsigned int filter_cnt; + + /* transaction snapshots */ + struct db_filter_snap *snapshots; + + /* userspace notification */ + bool notify_used; +}; + +/** + * Iterate over each item in the DB list + * @param iter the iterator + * @param list the list + * + * This macro acts as for()/while() conditional and iterates the following + * statement for each item in the given list. + * + */ +#define db_list_foreach(iter,list) \ + for (iter = (list); iter != NULL; iter = iter->next) + +struct db_api_rule_list *db_rule_dup(const struct db_api_rule_list *src); + +struct db_filter_col *db_col_init(uint32_t def_action); +int db_col_reset(struct db_filter_col *col, uint32_t def_action); +void db_col_release(struct db_filter_col *col); + +int db_col_valid(struct db_filter_col *col); + +int db_col_action_valid(const struct db_filter_col *col, uint32_t action); + +int db_col_merge(struct db_filter_col *col_dst, struct db_filter_col *col_src); + +int db_col_arch_exist(struct db_filter_col *col, uint32_t arch_token); + +int db_col_attr_get(const struct db_filter_col *col, + enum scmp_filter_attr attr, uint32_t *value); +uint32_t db_col_attr_read(const struct db_filter_col *col, + enum scmp_filter_attr attr); +int db_col_attr_set(struct db_filter_col *col, + enum scmp_filter_attr attr, uint32_t value); + +int db_col_db_new(struct db_filter_col *col, const struct arch_def *arch); +int db_col_db_add(struct db_filter_col *col, struct db_filter *db); +int db_col_db_remove(struct db_filter_col *col, uint32_t arch_token); + +int db_col_rule_add(struct db_filter_col *col, + bool strict, uint32_t action, int syscall, + unsigned int arg_cnt, const struct scmp_arg_cmp *arg_array); + +int db_col_syscall_priority(struct db_filter_col *col, + int syscall, uint8_t priority); + +int db_col_transaction_start(struct db_filter_col *col); +void db_col_transaction_abort(struct db_filter_col *col); +void db_col_transaction_commit(struct db_filter_col *col); + +int db_rule_add(struct db_filter *db, const struct db_api_rule_list *rule); + +#endif |