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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
commit | 5e61585d76ae77fd5e9e96ebabb57afa4d74880d (patch) | |
tree | 2b467823aaeebc7ef8bc9e3cabe8074eaef1666d /src/util/attr_clnt.c | |
parent | Initial commit. (diff) | |
download | postfix-5e61585d76ae77fd5e9e96ebabb57afa4d74880d.tar.xz postfix-5e61585d76ae77fd5e9e96ebabb57afa4d74880d.zip |
Adding upstream version 3.5.24.upstream/3.5.24
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/attr_clnt.c')
-rw-r--r-- | src/util/attr_clnt.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/src/util/attr_clnt.c b/src/util/attr_clnt.c new file mode 100644 index 0000000..0ec0944 --- /dev/null +++ b/src/util/attr_clnt.c @@ -0,0 +1,285 @@ +/*++ +/* NAME +/* attr_clnt 3 +/* SUMMARY +/* attribute query-reply client +/* SYNOPSIS +/* #include <attr_clnt.h> +/* +/* typedef int (*ATTR_CLNT_PRINT_FN) (VSTREAM *, int, va_list); +/* typedef int (*ATTR_CLNT_SCAN_FN) (VSTREAM *, int, va_list); +/* +/* ATTR_CLNT *attr_clnt_create(server, timeout, max_idle, max_ttl) +/* const char *server; +/* int timeout; +/* int max_idle; +/* int max_ttl; +/* +/* int attr_clnt_request(client, +/* send_flags, send_type, send_name, ..., ATTR_TYPE_END, +/* recv_flags, recv_type, recv_name, ..., ATTR_TYPE_END) +/* ATTR_CLNT *client; +/* int send_flags; +/* int send_type; +/* const char *send_name; +/* int recv_flags; +/* int recv_type; +/* const char *recv_name; +/* +/* void attr_clnt_free(client) +/* ATTR_CLNT *client; +/* +/* void attr_clnt_control(client, name, value, ... ATTR_CLNT_CTL_END) +/* ATTR_CLNT *client; +/* int name; +/* DESCRIPTION +/* This module implements a client for a simple attribute-based +/* protocol. The default protocol is described in attr_scan_plain(3). +/* +/* attr_clnt_create() creates a client handle. See auto_clnt(3) for +/* a description of the arguments. +/* +/* attr_clnt_request() sends the specified request attributes and +/* receives a reply. The reply argument specifies a name-value table. +/* The other arguments are as described in attr_print_plain(3). The +/* result is the number of attributes received or -1 in case of trouble. +/* +/* attr_clnt_free() destroys a client handle and closes its connection. +/* +/* attr_clnt_control() allows the user to fine tune the behavior of +/* the specified client. The arguments are a list of (name, value) +/* terminated with ATTR_CLNT_CTL_END. +/* The following lists the names and the types of the corresponding +/* value arguments. +/* .IP "ATTR_CLNT_CTL_PROTO(ATTR_CLNT_PRINT_FN, ATTR_CLNT_SCAN_FN)" +/* Specifies alternatives for the attr_plain_print() and +/* attr_plain_scan() functions. +/* .IP "ATTR_CLNT_CTL_REQ_LIMIT(int)" +/* The maximal number of requests per connection (default: 0, +/* i.e. no limit). To enable the limit, specify a value greater +/* than zero. +/* .IP "ATTR_CLNT_CTL_TRY_LIMIT(int)" +/* The maximal number of attempts to send a request before +/* giving up (default: 2). To disable the limit, specify a +/* value equal to zero. +/* .IP "ATTR_CLNT_CTL_TRY_DELAY(int)" +/* The time in seconds between attempts to send a request +/* (default: 1). Specify a value greater than zero. +/* DIAGNOSTICS +/* Warnings: communication failure. +/* SEE ALSO +/* auto_clnt(3), client endpoint management +/* attr_scan_plain(3), attribute protocol +/* attr_print_plain(3), attribute protocol +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <unistd.h> +#include <errno.h> + +/* Utility library. */ + +#include <msg.h> +#include <mymalloc.h> +#include <vstream.h> +#include <htable.h> +#include <attr.h> +#include <iostuff.h> +#include <compat_va_copy.h> +#include <auto_clnt.h> +#include <attr_clnt.h> + +/* Application-specific. */ + +struct ATTR_CLNT { + AUTO_CLNT *auto_clnt; + /* Remaining properties are set with attr_clnt_control(). */ + ATTR_CLNT_PRINT_FN print; + ATTR_CLNT_SCAN_FN scan; + int req_limit; + int req_count; + int try_limit; + int try_delay; +}; + +#define ATTR_CLNT_DEF_REQ_LIMIT (0) /* default per-session request limit */ +#define ATTR_CLNT_DEF_TRY_LIMIT (2) /* default request (re)try limit */ +#define ATTR_CLNT_DEF_TRY_DELAY (1) /* default request (re)try delay */ + +/* attr_clnt_free - destroy attribute client */ + +void attr_clnt_free(ATTR_CLNT *client) +{ + auto_clnt_free(client->auto_clnt); + myfree((void *) client); +} + +/* attr_clnt_create - create attribute client */ + +ATTR_CLNT *attr_clnt_create(const char *service, int timeout, + int max_idle, int max_ttl) +{ + ATTR_CLNT *client; + + client = (ATTR_CLNT *) mymalloc(sizeof(*client)); + client->auto_clnt = auto_clnt_create(service, timeout, max_idle, max_ttl); + client->scan = attr_vscan_plain; + client->print = attr_vprint_plain; + client->req_limit = ATTR_CLNT_DEF_REQ_LIMIT; + client->req_count = 0; + client->try_limit = ATTR_CLNT_DEF_TRY_LIMIT; + client->try_delay = ATTR_CLNT_DEF_TRY_DELAY; + return (client); +} + +/* attr_clnt_request - send query, receive reply */ + +int attr_clnt_request(ATTR_CLNT *client, int send_flags,...) +{ + const char *myname = "attr_clnt_request"; + VSTREAM *stream; + int count = 0; + va_list saved_ap; + va_list ap; + int type; + int recv_flags; + int err; + int ret; + + /* + * XXX If the stream is readable before we send anything, then assume the + * remote end disconnected. + * + * XXX For some reason we can't simply call the scan routine after the print + * routine, that messes up the argument list. + */ +#define SKIP_ARG(ap, type) { \ + (void) va_arg(ap, char *); \ + (void) va_arg(ap, type); \ + } +#define SKIP_ARG2(ap, t1, t2) { \ + SKIP_ARG(ap, t1); \ + (void) va_arg(ap, t2); \ + } + + /* Finalize argument lists before returning. */ + va_start(saved_ap, send_flags); + for (;;) { + errno = 0; + if ((stream = auto_clnt_access(client->auto_clnt)) != 0 + && readable(vstream_fileno(stream)) == 0) { + errno = 0; + VA_COPY(ap, saved_ap); + err = (client->print(stream, send_flags, ap) != 0 + || vstream_fflush(stream) != 0); + va_end(ap); + if (err == 0) { + VA_COPY(ap, saved_ap); + while ((type = va_arg(ap, int)) != ATTR_TYPE_END) { + switch (type) { + case ATTR_TYPE_STR: + SKIP_ARG(ap, char *); + break; + case ATTR_TYPE_DATA: + SKIP_ARG2(ap, ssize_t, char *); + break; + case ATTR_TYPE_INT: + SKIP_ARG(ap, int); + break; + case ATTR_TYPE_LONG: + SKIP_ARG(ap, long); + break; + case ATTR_TYPE_HASH: + (void) va_arg(ap, HTABLE *); + break; + default: + msg_panic("%s: unexpected attribute type %d", + myname, type); + } + } + recv_flags = va_arg(ap, int); + ret = client->scan(stream, recv_flags, ap); + va_end(ap); + /* Finalize argument lists before returning. */ + if (ret > 0) { + if (client->req_limit > 0 + && (client->req_count += 1) >= client->req_limit) { + auto_clnt_recover(client->auto_clnt); + client->req_count = 0; + } + break; + } + } + } + if ((++count >= client->try_limit && client->try_limit > 0) + || msg_verbose + || (errno && errno != EPIPE && errno != ENOENT && errno != ECONNRESET)) + msg_warn("problem talking to server %s: %m", + auto_clnt_name(client->auto_clnt)); + /* Finalize argument lists before returning. */ + if (count >= client->try_limit && client->try_limit > 0) { + ret = -1; + break; + } + sleep(client->try_delay); + auto_clnt_recover(client->auto_clnt); + client->req_count = 0; + } + /* Finalize argument lists before returning. */ + va_end(saved_ap); + return (ret); +} + +/* attr_clnt_control - fine control */ + +void attr_clnt_control(ATTR_CLNT *client, int name,...) +{ + const char *myname = "attr_clnt_control"; + va_list ap; + + for (va_start(ap, name); name != ATTR_CLNT_CTL_END; name = va_arg(ap, int)) { + switch (name) { + case ATTR_CLNT_CTL_PROTO: + client->print = va_arg(ap, ATTR_CLNT_PRINT_FN); + client->scan = va_arg(ap, ATTR_CLNT_SCAN_FN); + break; + case ATTR_CLNT_CTL_REQ_LIMIT: + client->req_limit = va_arg(ap, int); + if (client->req_limit < 0) + msg_panic("%s: bad request limit: %d", + myname, client->req_limit); + if (msg_verbose) + msg_info("%s: new request limit %d", + myname, client->req_limit); + break; + case ATTR_CLNT_CTL_TRY_LIMIT: + client->try_limit = va_arg(ap, int); + if (client->try_limit < 0) + msg_panic("%s: bad retry limit: %d", myname, client->try_limit); + if (msg_verbose) + msg_info("%s: new retry limit %d", myname, client->try_limit); + break; + case ATTR_CLNT_CTL_TRY_DELAY: + client->try_delay = va_arg(ap, int); + if (client->try_delay <= 0) + msg_panic("%s: bad retry delay: %d", myname, client->try_delay); + if (msg_verbose) + msg_info("%s: new retry delay %d", myname, client->try_delay); + break; + default: + msg_panic("%s: bad name %d", myname, name); + } + } + va_end(ap); +} |