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Diffstat (limited to 'REORG.TODO/nscd/nscd-client.h')
| -rw-r--r-- | REORG.TODO/nscd/nscd-client.h | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/REORG.TODO/nscd/nscd-client.h b/REORG.TODO/nscd/nscd-client.h new file mode 100644 index 0000000000..96170bff1b --- /dev/null +++ b/REORG.TODO/nscd/nscd-client.h @@ -0,0 +1,452 @@ +/* Copyright (c) 1998-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Thorsten Kukuk <kukuk@suse.de>, 1998. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C 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 the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* This file defines everything that client code should need to + know to talk to the nscd daemon. */ + +#ifndef _NSCD_CLIENT_H +#define _NSCD_CLIENT_H 1 + +#include <stdbool.h> +#include <stdint.h> +#include <string.h> +#include <time.h> +#include <sys/types.h> +#include <atomic.h> +#include <nscd-types.h> +#include <sys/uio.h> + + +/* Version number of the daemon interface */ +#define NSCD_VERSION 2 + +/* Path of the file where the PID of the running system is stored. */ +#define _PATH_NSCDPID "/var/run/nscd/nscd.pid" + +/* Path for the Unix domain socket. */ +#define _PATH_NSCDSOCKET "/var/run/nscd/socket" + +/* Path for the configuration file. */ +#define _PATH_NSCDCONF "/etc/nscd.conf" + +/* Maximum allowed length for the key. */ +#define MAXKEYLEN 1024 + + +/* Available services. */ +typedef enum +{ + GETPWBYNAME, + GETPWBYUID, + GETGRBYNAME, + GETGRBYGID, + GETHOSTBYNAME, + GETHOSTBYNAMEv6, + GETHOSTBYADDR, + GETHOSTBYADDRv6, + SHUTDOWN, /* Shut the server down. */ + GETSTAT, /* Get the server statistic. */ + INVALIDATE, /* Invalidate one special cache. */ + GETFDPW, + GETFDGR, + GETFDHST, + GETAI, + INITGROUPS, + GETSERVBYNAME, + GETSERVBYPORT, + GETFDSERV, + GETNETGRENT, + INNETGR, + GETFDNETGR, + LASTREQ +} request_type; + + +/* Header common to all requests */ +typedef struct +{ + int32_t version; /* Version number of the daemon interface. */ + request_type type; /* Service requested. */ + int32_t key_len; /* Key length. */ +} request_header; + + +/* Structure sent in reply to password query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t pw_name_len; + nscd_ssize_t pw_passwd_len; + uid_t pw_uid; + gid_t pw_gid; + nscd_ssize_t pw_gecos_len; + nscd_ssize_t pw_dir_len; + nscd_ssize_t pw_shell_len; +} pw_response_header; + + +/* Structure sent in reply to group query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t gr_name_len; + nscd_ssize_t gr_passwd_len; + gid_t gr_gid; + nscd_ssize_t gr_mem_cnt; +} gr_response_header; + + +/* Structure sent in reply to host query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t h_name_len; + nscd_ssize_t h_aliases_cnt; + int32_t h_addrtype; + int32_t h_length; + nscd_ssize_t h_addr_list_cnt; + int32_t error; +} hst_response_header; + + +/* Structure sent in reply to addrinfo query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t naddrs; + nscd_ssize_t addrslen; + nscd_ssize_t canonlen; + int32_t error; +} ai_response_header; + +/* Structure filled in by __nscd_getai. */ +struct nscd_ai_result +{ + int naddrs; + char *canon; + uint8_t *family; + char *addrs; +}; + +/* Structure sent in reply to initgroups query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t ngrps; +} initgr_response_header; + + +/* Structure sent in reply to services query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t s_name_len; + nscd_ssize_t s_proto_len; + nscd_ssize_t s_aliases_cnt; + int32_t s_port; +} serv_response_header; + + +/* Structure send in reply to netgroup query. Note that this struct is + sent also if the service is disabled or there is no record found. */ +typedef struct +{ + int32_t version; + int32_t found; + nscd_ssize_t nresults; + nscd_ssize_t result_len; +} netgroup_response_header; + +typedef struct +{ + int32_t version; + int32_t found; + int32_t result; +} innetgroup_response_header; + + +/* Type for offsets in data part of database. */ +typedef uint32_t ref_t; +/* Value for invalid/no reference. */ +#define ENDREF UINT32_MAX + +/* Timestamp type. */ +typedef uint64_t nscd_time_t; + +/* Maximum timestamp. */ +#define MAX_TIMEOUT_VALUE \ + (sizeof (time_t) == sizeof (long int) ? LONG_MAX : INT_MAX) + +/* Alignment requirement of the beginning of the data region. */ +#define ALIGN 16 + + +/* Head of record in data part of database. */ +struct datahead +{ + nscd_ssize_t allocsize; /* Allocated Bytes. */ + nscd_ssize_t recsize; /* Size of the record. */ + nscd_time_t timeout; /* Time when this entry becomes invalid. */ + uint8_t notfound; /* Nonzero if data has not been found. */ + uint8_t nreloads; /* Reloads without use. */ + uint8_t usable; /* False if the entry must be ignored. */ + uint8_t unused; /* Unused. */ + uint32_t ttl; /* TTL value used. */ + + /* We need to have the following element aligned for the response + header data types and their use in the 'struct dataset' types + defined in the XXXcache.c files. */ + union + { + pw_response_header pwdata; + gr_response_header grdata; + hst_response_header hstdata; + ai_response_header aidata; + initgr_response_header initgrdata; + serv_response_header servdata; + netgroup_response_header netgroupdata; + innetgroup_response_header innetgroupdata; + nscd_ssize_t align1; + nscd_time_t align2; + } data[0]; +}; + +static inline time_t +datahead_init_common (struct datahead *head, nscd_ssize_t allocsize, + nscd_ssize_t recsize, uint32_t ttl) +{ + /* Initialize so that we don't write out junk in uninitialized data to the + cache. */ + memset (head, 0, sizeof (*head)); + + head->allocsize = allocsize; + head->recsize = recsize; + head->usable = true; + + head->ttl = ttl; + + /* Compute and return the timeout time. */ + return head->timeout = time (NULL) + ttl; +} + +static inline time_t +datahead_init_pos (struct datahead *head, nscd_ssize_t allocsize, + nscd_ssize_t recsize, uint8_t nreloads, uint32_t ttl) +{ + time_t ret = datahead_init_common (head, allocsize, recsize, ttl); + + head->notfound = false; + head->nreloads = nreloads; + + return ret; +} + +static inline time_t +datahead_init_neg (struct datahead *head, nscd_ssize_t allocsize, + nscd_ssize_t recsize, uint32_t ttl) +{ + time_t ret = datahead_init_common (head, allocsize, recsize, ttl); + + /* We don't need to touch nreloads here since it is set to our desired value + (0) when we clear the structure. */ + head->notfound = true; + + return ret; +} + +/* Structure for one hash table entry. */ +struct hashentry +{ + request_type type:8; /* Which type of dataset. */ + bool first; /* True if this was the original key. */ + nscd_ssize_t len; /* Length of key. */ + ref_t key; /* Pointer to key. */ + int32_t owner; /* If secure table, this is the owner. */ + ref_t next; /* Next entry in this hash bucket list. */ + ref_t packet; /* Records for the result. */ + union + { + struct hashentry *dellist; /* Next record to be deleted. This can be a + pointer since only nscd uses this field. */ + ref_t *prevp; /* Pointer to field containing forward + reference. */ + }; +}; + + +/* Current persistent database version. */ +#define DB_VERSION 2 + +/* Maximum time allowed between updates of the timestamp. */ +#define MAPPING_TIMEOUT (5 * 60) + + +/* Used indices for the EXTRA_DATA element of 'database_pers_head'. + Each database has its own indices. */ +#define NSCD_HST_IDX_CONF_TIMESTAMP 0 + + +/* Header of persistent database file. */ +struct database_pers_head +{ + int32_t version; + int32_t header_size; + volatile int32_t gc_cycle; + volatile int32_t nscd_certainly_running; + volatile nscd_time_t timestamp; + /* Room for extensions. */ + volatile uint32_t extra_data[4]; + + nscd_ssize_t module; + nscd_ssize_t data_size; + + nscd_ssize_t first_free; /* Offset of first free byte in data area. */ + + nscd_ssize_t nentries; + nscd_ssize_t maxnentries; + nscd_ssize_t maxnsearched; + + uint64_t poshit; + uint64_t neghit; + uint64_t posmiss; + uint64_t negmiss; + + uint64_t rdlockdelayed; + uint64_t wrlockdelayed; + + uint64_t addfailed; + + ref_t array[0]; +}; + + +/* Mapped database record. */ +struct mapped_database +{ + const struct database_pers_head *head; + const char *data; + size_t mapsize; + int counter; /* > 0 indicates it is usable. */ + size_t datasize; +}; +#define NO_MAPPING ((struct mapped_database *) -1l) + +struct locked_map_ptr +{ + int lock; + struct mapped_database *mapped; +}; +#define libc_locked_map_ptr(class, name) class struct locked_map_ptr name + +/* Try acquiring lock for mapptr, returns true if it succeeds, false + if not. */ +static inline bool +__nscd_acquire_maplock (volatile struct locked_map_ptr *mapptr) +{ + int cnt = 0; + while (__builtin_expect (atomic_compare_and_exchange_val_acq (&mapptr->lock, + 1, 0) != 0, 0)) + { + // XXX Best number of rounds? + if (__glibc_unlikely (++cnt > 5)) + return false; + + atomic_spin_nop (); + } + + return true; +} + + +/* Open socket connection to nscd server. */ +extern int __nscd_open_socket (const char *key, size_t keylen, + request_type type, void *response, + size_t responselen) attribute_hidden; + +/* Try to get a file descriptor for the shared meory segment + containing the database. */ +extern struct mapped_database *__nscd_get_mapping (request_type type, + const char *key, + struct mapped_database **mappedp) attribute_hidden; + +/* Get reference of mapping. */ +extern struct mapped_database *__nscd_get_map_ref (request_type type, + const char *name, + volatile struct locked_map_ptr *mapptr, + int *gc_cyclep); + +/* Unmap database. */ +extern void __nscd_unmap (struct mapped_database *mapped); + +/* Drop reference of mapping. */ +static int +__attribute__ ((unused)) +__nscd_drop_map_ref (struct mapped_database *map, int *gc_cycle) +{ + if (map != NO_MAPPING) + { + int now_cycle = map->head->gc_cycle; + if (__glibc_unlikely (now_cycle != *gc_cycle)) + { + /* We might have read inconsistent data. */ + *gc_cycle = now_cycle; + return -1; + } + + if (atomic_decrement_val (&map->counter) == 0) + __nscd_unmap (map); + } + + return 0; +} + + +/* Search the mapped database. */ +extern struct datahead *__nscd_cache_search (request_type type, + const char *key, + size_t keylen, + const struct mapped_database *mapped, + size_t datalen); + +/* Wrappers around read, readv and write that only read/write less than LEN + bytes on error or EOF. */ +extern ssize_t __readall (int fd, void *buf, size_t len) + attribute_hidden; +extern ssize_t __readvall (int fd, const struct iovec *iov, int iovcnt) + attribute_hidden; +extern ssize_t writeall (int fd, const void *buf, size_t len) + attribute_hidden; +extern ssize_t sendfileall (int tofd, int fromfd, off_t off, size_t len) + attribute_hidden; + +/* Get netlink timestamp counter from mapped area or zero. */ +extern uint32_t __nscd_get_nl_timestamp (void); + +#endif /* nscd.h */ |