diff options
Diffstat (limited to 'contrib/postgres_fdw/option.c')
| -rw-r--r-- | contrib/postgres_fdw/option.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c new file mode 100644 index 0000000..af5422d --- /dev/null +++ b/contrib/postgres_fdw/option.c @@ -0,0 +1,403 @@ +/*------------------------------------------------------------------------- + * + * option.c + * FDW option handling for postgres_fdw + * + * Portions Copyright (c) 2012-2020, PostgreSQL Global Development Group + * + * IDENTIFICATION + * contrib/postgres_fdw/option.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/reloptions.h" +#include "catalog/pg_foreign_server.h" +#include "catalog/pg_foreign_table.h" +#include "catalog/pg_user_mapping.h" +#include "commands/defrem.h" +#include "commands/extension.h" +#include "postgres_fdw.h" +#include "utils/builtins.h" +#include "utils/varlena.h" + +/* + * Describes the valid options for objects that this wrapper uses. + */ +typedef struct PgFdwOption +{ + const char *keyword; + Oid optcontext; /* OID of catalog in which option may appear */ + bool is_libpq_opt; /* true if it's used in libpq */ +} PgFdwOption; + +/* + * Valid options for postgres_fdw. + * Allocated and filled in InitPgFdwOptions. + */ +static PgFdwOption *postgres_fdw_options; + +/* + * Valid options for libpq. + * Allocated and filled in InitPgFdwOptions. + */ +static PQconninfoOption *libpq_options; + +/* + * Helper functions + */ +static void InitPgFdwOptions(void); +static bool is_valid_option(const char *keyword, Oid context); +static bool is_libpq_option(const char *keyword); + +#include "miscadmin.h" + +/* + * Validate the generic options given to a FOREIGN DATA WRAPPER, SERVER, + * USER MAPPING or FOREIGN TABLE that uses postgres_fdw. + * + * Raise an ERROR if the option or its value is considered invalid. + */ +PG_FUNCTION_INFO_V1(postgres_fdw_validator); + +Datum +postgres_fdw_validator(PG_FUNCTION_ARGS) +{ + List *options_list = untransformRelOptions(PG_GETARG_DATUM(0)); + Oid catalog = PG_GETARG_OID(1); + ListCell *cell; + + /* Build our options lists if we didn't yet. */ + InitPgFdwOptions(); + + /* + * Check that only options supported by postgres_fdw, and allowed for the + * current object type, are given. + */ + foreach(cell, options_list) + { + DefElem *def = (DefElem *) lfirst(cell); + + if (!is_valid_option(def->defname, catalog)) + { + /* + * Unknown option specified, complain about it. Provide a hint + * with list of valid options for the object. + */ + PgFdwOption *opt; + StringInfoData buf; + + initStringInfo(&buf); + for (opt = postgres_fdw_options; opt->keyword; opt++) + { + if (catalog == opt->optcontext) + appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "", + opt->keyword); + } + + ereport(ERROR, + (errcode(ERRCODE_FDW_INVALID_OPTION_NAME), + errmsg("invalid option \"%s\"", def->defname), + errhint("Valid options in this context are: %s", + buf.data))); + } + + /* + * Validate option value, when we can do so without any context. + */ + if (strcmp(def->defname, "use_remote_estimate") == 0 || + strcmp(def->defname, "updatable") == 0) + { + /* these accept only boolean values */ + (void) defGetBoolean(def); + } + else if (strcmp(def->defname, "fdw_startup_cost") == 0 || + strcmp(def->defname, "fdw_tuple_cost") == 0) + { + /* + * These must have a floating point value greater than or equal to + * zero. + */ + double val; + char *endp; + + val = strtod(defGetString(def), &endp); + if (*endp || val < 0) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("\"%s\" must be a floating point value greater than or equal to zero", + def->defname))); + } + else if (strcmp(def->defname, "extensions") == 0) + { + /* check list syntax, warn about uninstalled extensions */ + (void) ExtractExtensionList(defGetString(def), true); + } + else if (strcmp(def->defname, "fetch_size") == 0) + { + int fetch_size; + + fetch_size = strtol(defGetString(def), NULL, 10); + if (fetch_size <= 0) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("\"%s\" must be an integer value greater than zero", + def->defname))); + } + else if (strcmp(def->defname, "password_required") == 0) + { + bool pw_required = defGetBoolean(def); + + /* + * Only the superuser may set this option on a user mapping, or + * alter a user mapping on which this option is set. We allow a + * user to clear this option if it's set - in fact, we don't have + * a choice since we can't see the old mapping when validating an + * alter. + */ + if (!superuser() && !pw_required) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("password_required=false is superuser-only"), + errhint("User mappings with the password_required option set to false may only be created or modified by the superuser"))); + } + else if (strcmp(def->defname, "sslcert") == 0 || + strcmp(def->defname, "sslkey") == 0) + { + /* similarly for sslcert / sslkey on user mapping */ + if (catalog == UserMappingRelationId && !superuser()) + ereport(ERROR, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("sslcert and sslkey are superuser-only"), + errhint("User mappings with the sslcert or sslkey options set may only be created or modified by the superuser"))); + } + } + + PG_RETURN_VOID(); +} + +/* + * Initialize option lists. + */ +static void +InitPgFdwOptions(void) +{ + int num_libpq_opts; + PQconninfoOption *lopt; + PgFdwOption *popt; + + /* non-libpq FDW-specific FDW options */ + static const PgFdwOption non_libpq_options[] = { + {"schema_name", ForeignTableRelationId, false}, + {"table_name", ForeignTableRelationId, false}, + {"column_name", AttributeRelationId, false}, + /* use_remote_estimate is available on both server and table */ + {"use_remote_estimate", ForeignServerRelationId, false}, + {"use_remote_estimate", ForeignTableRelationId, false}, + /* cost factors */ + {"fdw_startup_cost", ForeignServerRelationId, false}, + {"fdw_tuple_cost", ForeignServerRelationId, false}, + /* shippable extensions */ + {"extensions", ForeignServerRelationId, false}, + /* updatable is available on both server and table */ + {"updatable", ForeignServerRelationId, false}, + {"updatable", ForeignTableRelationId, false}, + /* fetch_size is available on both server and table */ + {"fetch_size", ForeignServerRelationId, false}, + {"fetch_size", ForeignTableRelationId, false}, + {"password_required", UserMappingRelationId, false}, + + /* + * sslcert and sslkey are in fact libpq options, but we repeat them + * here to allow them to appear in both foreign server context (when + * we generate libpq options) and user mapping context (from here). + */ + {"sslcert", UserMappingRelationId, true}, + {"sslkey", UserMappingRelationId, true}, + + {NULL, InvalidOid, false} + }; + + /* Prevent redundant initialization. */ + if (postgres_fdw_options) + return; + + /* + * Get list of valid libpq options. + * + * To avoid unnecessary work, we get the list once and use it throughout + * the lifetime of this backend process. We don't need to care about + * memory context issues, because PQconndefaults allocates with malloc. + */ + libpq_options = PQconndefaults(); + if (!libpq_options) /* assume reason for failure is OOM */ + ereport(ERROR, + (errcode(ERRCODE_FDW_OUT_OF_MEMORY), + errmsg("out of memory"), + errdetail("Could not get libpq's default connection options."))); + + /* Count how many libpq options are available. */ + num_libpq_opts = 0; + for (lopt = libpq_options; lopt->keyword; lopt++) + num_libpq_opts++; + + /* + * Construct an array which consists of all valid options for + * postgres_fdw, by appending FDW-specific options to libpq options. + * + * We use plain malloc here to allocate postgres_fdw_options because it + * lives as long as the backend process does. Besides, keeping + * libpq_options in memory allows us to avoid copying every keyword + * string. + */ + postgres_fdw_options = (PgFdwOption *) + malloc(sizeof(PgFdwOption) * num_libpq_opts + + sizeof(non_libpq_options)); + if (postgres_fdw_options == NULL) + ereport(ERROR, + (errcode(ERRCODE_FDW_OUT_OF_MEMORY), + errmsg("out of memory"))); + + popt = postgres_fdw_options; + for (lopt = libpq_options; lopt->keyword; lopt++) + { + /* Hide debug options, as well as settings we override internally. */ + if (strchr(lopt->dispchar, 'D') || + strcmp(lopt->keyword, "fallback_application_name") == 0 || + strcmp(lopt->keyword, "client_encoding") == 0) + continue; + + /* We don't have to copy keyword string, as described above. */ + popt->keyword = lopt->keyword; + + /* + * "user" and any secret options are allowed only on user mappings. + * Everything else is a server option. + */ + if (strcmp(lopt->keyword, "user") == 0 || strchr(lopt->dispchar, '*')) + popt->optcontext = UserMappingRelationId; + else + popt->optcontext = ForeignServerRelationId; + popt->is_libpq_opt = true; + + popt++; + } + + /* Append FDW-specific options and dummy terminator. */ + memcpy(popt, non_libpq_options, sizeof(non_libpq_options)); +} + +/* + * Check whether the given option is one of the valid postgres_fdw options. + * context is the Oid of the catalog holding the object the option is for. + */ +static bool +is_valid_option(const char *keyword, Oid context) +{ + PgFdwOption *opt; + + Assert(postgres_fdw_options); /* must be initialized already */ + + for (opt = postgres_fdw_options; opt->keyword; opt++) + { + if (context == opt->optcontext && strcmp(opt->keyword, keyword) == 0) + return true; + } + + return false; +} + +/* + * Check whether the given option is one of the valid libpq options. + */ +static bool +is_libpq_option(const char *keyword) +{ + PgFdwOption *opt; + + Assert(postgres_fdw_options); /* must be initialized already */ + + for (opt = postgres_fdw_options; opt->keyword; opt++) + { + if (opt->is_libpq_opt && strcmp(opt->keyword, keyword) == 0) + return true; + } + + return false; +} + +/* + * Generate key-value arrays which include only libpq options from the + * given list (which can contain any kind of options). Caller must have + * allocated large-enough arrays. Returns number of options found. + */ +int +ExtractConnectionOptions(List *defelems, const char **keywords, + const char **values) +{ + ListCell *lc; + int i; + + /* Build our options lists if we didn't yet. */ + InitPgFdwOptions(); + + i = 0; + foreach(lc, defelems) + { + DefElem *d = (DefElem *) lfirst(lc); + + if (is_libpq_option(d->defname)) + { + keywords[i] = d->defname; + values[i] = defGetString(d); + i++; + } + } + return i; +} + +/* + * Parse a comma-separated string and return a List of the OIDs of the + * extensions named in the string. If any names in the list cannot be + * found, report a warning if warnOnMissing is true, else just silently + * ignore them. + */ +List * +ExtractExtensionList(const char *extensionsString, bool warnOnMissing) +{ + List *extensionOids = NIL; + List *extlist; + ListCell *lc; + + /* SplitIdentifierString scribbles on its input, so pstrdup first */ + if (!SplitIdentifierString(pstrdup(extensionsString), ',', &extlist)) + { + /* syntax error in name list */ + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("parameter \"%s\" must be a list of extension names", + "extensions"))); + } + + foreach(lc, extlist) + { + const char *extension_name = (const char *) lfirst(lc); + Oid extension_oid = get_extension_oid(extension_name, true); + + if (OidIsValid(extension_oid)) + { + extensionOids = lappend_oid(extensionOids, extension_oid); + } + else if (warnOnMissing) + { + ereport(WARNING, + (errcode(ERRCODE_UNDEFINED_OBJECT), + errmsg("extension \"%s\" is not installed", + extension_name))); + } + } + + list_free(extlist); + return extensionOids; +} |