hbafuncs.c

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/*-------------------------------------------------------------------------
 *
 * hbafuncs.c
 *    Support functions for SQL views of authentication files.
 *
 * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    src/backend/utils/adt/hbafuncs.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"
 
#include "catalog/objectaddress.h"
#include "common/ip.h"
#include "funcapi.h"
#include "libpq/hba.h"
#include "miscadmin.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/guc.h"
 
 
static ArrayType *get_hba_options(HbaLine *hba);
static void fill_hba_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
                          int lineno, HbaLine *hba, const char *err_msg);
static void fill_hba_view(Tuplestorestate *tuple_store, TupleDesc tupdesc);
static void fill_ident_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
                            int lineno, IdentLine *ident, const char *err_msg);
static void fill_ident_view(Tuplestorestate *tuple_store, TupleDesc tupdesc);
 
 
/*
 * This macro specifies the maximum number of authentication options
 * that are possible with any given authentication method that is supported.
 * Currently LDAP supports 11, and there are 3 that are not dependent on
 * the auth method here.  It may not actually be possible to set all of them
 * at the same time, but we'll set the macro value high enough to be
 * conservative and avoid warnings from static analysis tools.
 */
#define MAX_HBA_OPTIONS 14
 
/*
 * Create a text array listing the options specified in the HBA line.
 * Return NULL if no options are specified.
 */
static ArrayType *
get_hba_options(HbaLine *hba)
{
    int         noptions;
    Datum       options[MAX_HBA_OPTIONS];
 
    noptions = 0;
 
    if (hba->auth_method == uaGSS || hba->auth_method == uaSSPI)
    {
        if (hba->include_realm)
            options[noptions++] =
                CStringGetTextDatum("include_realm=true");
 
        if (hba->krb_realm)
            options[noptions++] =
                CStringGetTextDatum(psprintf("krb_realm=%s", hba->krb_realm));
    }
 
    if (hba->usermap)
        options[noptions++] =
            CStringGetTextDatum(psprintf("map=%s", hba->usermap));
 
    if (hba->clientcert != clientCertOff)
        options[noptions++] =
            CStringGetTextDatum(psprintf("clientcert=%s", (hba->clientcert == clientCertCA) ? "verify-ca" : "verify-full"));
 
    if (hba->pamservice)
        options[noptions++] =
            CStringGetTextDatum(psprintf("pamservice=%s", hba->pamservice));
 
    if (hba->auth_method == uaLDAP)
    {
        if (hba->ldapserver)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapserver=%s", hba->ldapserver));
 
        if (hba->ldapport)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapport=%d", hba->ldapport));
 
        if (hba->ldaptls)
            options[noptions++] =
                CStringGetTextDatum("ldaptls=true");
 
        if (hba->ldapprefix)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapprefix=%s", hba->ldapprefix));
 
        if (hba->ldapsuffix)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapsuffix=%s", hba->ldapsuffix));
 
        if (hba->ldapbasedn)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapbasedn=%s", hba->ldapbasedn));
 
        if (hba->ldapbinddn)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapbinddn=%s", hba->ldapbinddn));
 
        if (hba->ldapbindpasswd)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapbindpasswd=%s",
                                             hba->ldapbindpasswd));
 
        if (hba->ldapsearchattribute)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapsearchattribute=%s",
                                             hba->ldapsearchattribute));
 
        if (hba->ldapsearchfilter)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapsearchfilter=%s",
                                             hba->ldapsearchfilter));
 
        if (hba->ldapscope)
            options[noptions++] =
                CStringGetTextDatum(psprintf("ldapscope=%d", hba->ldapscope));
    }
 
    if (hba->auth_method == uaRADIUS)
    {
        if (hba->radiusservers_s)
            options[noptions++] =
                CStringGetTextDatum(psprintf("radiusservers=%s", hba->radiusservers_s));
 
        if (hba->radiussecrets_s)
            options[noptions++] =
                CStringGetTextDatum(psprintf("radiussecrets=%s", hba->radiussecrets_s));
 
        if (hba->radiusidentifiers_s)
            options[noptions++] =
                CStringGetTextDatum(psprintf("radiusidentifiers=%s", hba->radiusidentifiers_s));
 
        if (hba->radiusports_s)
            options[noptions++] =
                CStringGetTextDatum(psprintf("radiusports=%s", hba->radiusports_s));
    }
 
    /* If you add more options, consider increasing MAX_HBA_OPTIONS. */
    Assert(noptions <= MAX_HBA_OPTIONS);
 
    if (noptions > 0)
        return construct_array(options, noptions, TEXTOID, -1, false, TYPALIGN_INT);
    else
        return NULL;
}
 
/* Number of columns in pg_hba_file_rules view */
#define NUM_PG_HBA_FILE_RULES_ATTS   9
 
/*
 * fill_hba_line
 *      Build one row of pg_hba_file_rules view, add it to tuplestore.
 *
 * tuple_store: where to store data
 * tupdesc: tuple descriptor for the view
 * lineno: pg_hba.conf line number (must always be valid)
 * hba: parsed line data (can be NULL, in which case err_msg should be set)
 * err_msg: error message (NULL if none)
 *
 * Note: leaks memory, but we don't care since this is run in a short-lived
 * memory context.
 */
static void
fill_hba_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
              int lineno, HbaLine *hba, const char *err_msg)
{
    Datum       values[NUM_PG_HBA_FILE_RULES_ATTS];
    bool        nulls[NUM_PG_HBA_FILE_RULES_ATTS];
    char        buffer[NI_MAXHOST];
    HeapTuple   tuple;
    int         index;
    ListCell   *lc;
    const char *typestr;
    const char *addrstr;
    const char *maskstr;
    ArrayType  *options;
 
    Assert(tupdesc->natts == NUM_PG_HBA_FILE_RULES_ATTS);
 
    memset(values, 0, sizeof(values));
    memset(nulls, 0, sizeof(nulls));
    index = 0;
 
    /* line_number */
    values[index++] = Int32GetDatum(lineno);
 
    if (hba != NULL)
    {
        /* type */
        /* Avoid a default: case so compiler will warn about missing cases */
        typestr = NULL;
        switch (hba->conntype)
        {
            case ctLocal:
                typestr = "local";
                break;
            case ctHost:
                typestr = "host";
                break;
            case ctHostSSL:
                typestr = "hostssl";
                break;
            case ctHostNoSSL:
                typestr = "hostnossl";
                break;
            case ctHostGSS:
                typestr = "hostgssenc";
                break;
            case ctHostNoGSS:
                typestr = "hostnogssenc";
                break;
        }
        if (typestr)
            values[index++] = CStringGetTextDatum(typestr);
        else
            nulls[index++] = true;
 
        /* database */
        if (hba->databases)
        {
            /*
             * Flatten AuthToken list to string list.  It might seem that we
             * should re-quote any quoted tokens, but that has been rejected
             * on the grounds that it makes it harder to compare the array
             * elements to other system catalogs.  That makes entries like
             * "all" or "samerole" formally ambiguous ... but users who name
             * databases/roles that way are inflicting their own pain.
             */
            List       *names = NIL;
 
            foreach(lc, hba->databases)
            {
                AuthToken  *tok = lfirst(lc);
 
                names = lappend(names, tok->string);
            }
            values[index++] = PointerGetDatum(strlist_to_textarray(names));
        }
        else
            nulls[index++] = true;
 
        /* user */
        if (hba->roles)
        {
            /* Flatten AuthToken list to string list; see comment above */
            List       *roles = NIL;
 
            foreach(lc, hba->roles)
            {
                AuthToken  *tok = lfirst(lc);
 
                roles = lappend(roles, tok->string);
            }
            values[index++] = PointerGetDatum(strlist_to_textarray(roles));
        }
        else
            nulls[index++] = true;
 
        /* address and netmask */
        /* Avoid a default: case so compiler will warn about missing cases */
        addrstr = maskstr = NULL;
        switch (hba->ip_cmp_method)
        {
            case ipCmpMask:
                if (hba->hostname)
                {
                    addrstr = hba->hostname;
                }
                else
                {
                    /*
                     * Note: if pg_getnameinfo_all fails, it'll set buffer to
                     * "???", which we want to return.
                     */
                    if (hba->addrlen > 0)
                    {
                        if (pg_getnameinfo_all(&hba->addr, hba->addrlen,
                                               buffer, sizeof(buffer),
                                               NULL, 0,
                                               NI_NUMERICHOST) == 0)
                            clean_ipv6_addr(hba->addr.ss_family, buffer);
                        addrstr = pstrdup(buffer);
                    }
                    if (hba->masklen > 0)
                    {
                        if (pg_getnameinfo_all(&hba->mask, hba->masklen,
                                               buffer, sizeof(buffer),
                                               NULL, 0,
                                               NI_NUMERICHOST) == 0)
                            clean_ipv6_addr(hba->mask.ss_family, buffer);
                        maskstr = pstrdup(buffer);
                    }
                }
                break;
            case ipCmpAll:
                addrstr = "all";
                break;
            case ipCmpSameHost:
                addrstr = "samehost";
                break;
            case ipCmpSameNet:
                addrstr = "samenet";
                break;
        }
        if (addrstr)
            values[index++] = CStringGetTextDatum(addrstr);
        else
            nulls[index++] = true;
        if (maskstr)
            values[index++] = CStringGetTextDatum(maskstr);
        else
            nulls[index++] = true;
 
        /* auth_method */
        values[index++] = CStringGetTextDatum(hba_authname(hba->auth_method));
 
        /* options */
        options = get_hba_options(hba);
        if (options)
            values[index++] = PointerGetDatum(options);
        else
            nulls[index++] = true;
    }
    else
    {
        /* no parsing result, so set relevant fields to nulls */
        memset(&nulls[1], true, (NUM_PG_HBA_FILE_RULES_ATTS - 2) * sizeof(bool));
    }
 
    /* error */
    if (err_msg)
        values[NUM_PG_HBA_FILE_RULES_ATTS - 1] = CStringGetTextDatum(err_msg);
    else
        nulls[NUM_PG_HBA_FILE_RULES_ATTS - 1] = true;
 
    tuple = heap_form_tuple(tupdesc, values, nulls);
    tuplestore_puttuple(tuple_store, tuple);
}
 
/*
 * fill_hba_view
 *      Read the pg_hba.conf file and fill the tuplestore with view records.
 */
static void
fill_hba_view(Tuplestorestate *tuple_store, TupleDesc tupdesc)
{
    FILE       *file;
    List       *hba_lines = NIL;
    ListCell   *line;
    MemoryContext linecxt;
    MemoryContext hbacxt;
    MemoryContext oldcxt;
 
    /*
     * In the unlikely event that we can't open pg_hba.conf, we throw an
     * error, rather than trying to report it via some sort of view entry.
     * (Most other error conditions should result in a message in a view
     * entry.)
     */
    file = AllocateFile(HbaFileName, "r");
    if (file == NULL)
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not open configuration file \"%s\": %m",
                        HbaFileName)));
 
    linecxt = tokenize_auth_file(HbaFileName, file, &hba_lines, DEBUG3);
    FreeFile(file);
 
    /* Now parse all the lines */
    hbacxt = AllocSetContextCreate(CurrentMemoryContext,
                                   "hba parser context",
                                   ALLOCSET_SMALL_SIZES);
    oldcxt = MemoryContextSwitchTo(hbacxt);
    foreach(line, hba_lines)
    {
        TokenizedAuthLine *tok_line = (TokenizedAuthLine *) lfirst(line);
        HbaLine    *hbaline = NULL;
 
        /* don't parse lines that already have errors */
        if (tok_line->err_msg == NULL)
            hbaline = parse_hba_line(tok_line, DEBUG3);
 
        fill_hba_line(tuple_store, tupdesc, tok_line->line_num,
                      hbaline, tok_line->err_msg);
    }
 
    /* Free tokenizer memory */
    MemoryContextDelete(linecxt);
    /* Free parse_hba_line memory */
    MemoryContextSwitchTo(oldcxt);
    MemoryContextDelete(hbacxt);
}
 
/*
 * pg_hba_file_rules
 *
 * SQL-accessible set-returning function to return all the entries in the
 * pg_hba.conf file.
 */
Datum
pg_hba_file_rules(PG_FUNCTION_ARGS)
{
    ReturnSetInfo *rsi;
 
    /*
     * Build tuplestore to hold the result rows.  We must use the Materialize
     * mode to be safe against HBA file changes while the cursor is open. It's
     * also more efficient than having to look up our current position in the
     * parsed list every time.
     */
    SetSingleFuncCall(fcinfo, 0);
 
    /* Fill the tuplestore */
    rsi = (ReturnSetInfo *) fcinfo->resultinfo;
    fill_hba_view(rsi->setResult, rsi->setDesc);
 
    PG_RETURN_NULL();
}
 
/* Number of columns in pg_ident_file_mappings view */
#define NUM_PG_IDENT_FILE_MAPPINGS_ATTS  5
 
/*
 * fill_ident_line: build one row of pg_ident_file_mappings view, add it to
 * tuplestore
 *
 * tuple_store: where to store data
 * tupdesc: tuple descriptor for the view
 * lineno: pg_ident.conf line number (must always be valid)
 * ident: parsed line data (can be NULL, in which case err_msg should be set)
 * err_msg: error message (NULL if none)
 *
 * Note: leaks memory, but we don't care since this is run in a short-lived
 * memory context.
 */
static void
fill_ident_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
                int lineno, IdentLine *ident, const char *err_msg)
{
    Datum       values[NUM_PG_IDENT_FILE_MAPPINGS_ATTS];
    bool        nulls[NUM_PG_IDENT_FILE_MAPPINGS_ATTS];
    HeapTuple   tuple;
    int         index;
 
    Assert(tupdesc->natts == NUM_PG_IDENT_FILE_MAPPINGS_ATTS);
 
    memset(values, 0, sizeof(values));
    memset(nulls, 0, sizeof(nulls));
    index = 0;
 
    /* line_number */
    values[index++] = Int32GetDatum(lineno);
 
    if (ident != NULL)
    {
        values[index++] = CStringGetTextDatum(ident->usermap);
        values[index++] = CStringGetTextDatum(ident->ident_user);
        values[index++] = CStringGetTextDatum(ident->pg_role);
    }
    else
    {
        /* no parsing result, so set relevant fields to nulls */
        memset(&nulls[1], true, (NUM_PG_IDENT_FILE_MAPPINGS_ATTS - 2) * sizeof(bool));
    }
 
    /* error */
    if (err_msg)
        values[NUM_PG_IDENT_FILE_MAPPINGS_ATTS - 1] = CStringGetTextDatum(err_msg);
    else
        nulls[NUM_PG_IDENT_FILE_MAPPINGS_ATTS - 1] = true;
 
    tuple = heap_form_tuple(tupdesc, values, nulls);
    tuplestore_puttuple(tuple_store, tuple);
}
 
/*
 * Read the pg_ident.conf file and fill the tuplestore with view records.
 */
static void
fill_ident_view(Tuplestorestate *tuple_store, TupleDesc tupdesc)
{
    FILE       *file;
    List       *ident_lines = NIL;
    ListCell   *line;
    MemoryContext linecxt;
    MemoryContext identcxt;
    MemoryContext oldcxt;
 
    /*
     * In the unlikely event that we can't open pg_ident.conf, we throw an
     * error, rather than trying to report it via some sort of view entry.
     * (Most other error conditions should result in a message in a view
     * entry.)
     */
    file = AllocateFile(IdentFileName, "r");
    if (file == NULL)
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not open usermap file \"%s\": %m",
                        IdentFileName)));
 
    linecxt = tokenize_auth_file(HbaFileName, file, &ident_lines, DEBUG3);
    FreeFile(file);
 
    /* Now parse all the lines */
    identcxt = AllocSetContextCreate(CurrentMemoryContext,
                                     "ident parser context",
                                     ALLOCSET_SMALL_SIZES);
    oldcxt = MemoryContextSwitchTo(identcxt);
    foreach(line, ident_lines)
    {
        TokenizedAuthLine *tok_line = (TokenizedAuthLine *) lfirst(line);
        IdentLine  *identline = NULL;
 
        /* don't parse lines that already have errors */
        if (tok_line->err_msg == NULL)
            identline = parse_ident_line(tok_line, DEBUG3);
 
        fill_ident_line(tuple_store, tupdesc, tok_line->line_num, identline,
                        tok_line->err_msg);
    }
 
    /* Free tokenizer memory */
    MemoryContextDelete(linecxt);
    /* Free parse_ident_line memory */
    MemoryContextSwitchTo(oldcxt);
    MemoryContextDelete(identcxt);
}
 
/*
 * SQL-accessible SRF to return all the entries in the pg_ident.conf file.
 */
Datum
pg_ident_file_mappings(PG_FUNCTION_ARGS)
{
    ReturnSetInfo *rsi;
 
    /*
     * Build tuplestore to hold the result rows.  We must use the Materialize
     * mode to be safe against HBA file changes while the cursor is open. It's
     * also more efficient than having to look up our current position in the
     * parsed list every time.
     */
    SetSingleFuncCall(fcinfo, 0);
 
    /* Fill the tuplestore */
    rsi = (ReturnSetInfo *) fcinfo->resultinfo;
    fill_ident_view(rsi->setResult, rsi->setDesc);
 
    PG_RETURN_NULL();
}