Rename some variables related to ident files in hba.{c,h}

The code that handles authentication for user maps was pretty confusing
with its choice of variable names.  It involves two types of users: a
system user and a Postgres user (well, role), and these were not named
consistently throughout the code that processes the user maps loaded
from pg_ident.conf at authentication.

This commit changes the following things to improve the situation:
- Rename "pg_role" to "pg_user" and "token" to "system_user" in
IndetLine.  These choices are more consistent with the pg_ident.conf
example in the docs, as well.  "token" has been introduced recently in
fc579e1, and it is way worse than the choice before that, "ident_user".
- Switch the order of the fields in IdentLine to map with the order of
the items in the ident files, as of map name, system user and PG user.
- In check_ident_usermap(), rename "regexp_pgrole" to "expanded_pg_user"
when processing a regexp for the system user entry in a user map.  This
variable does not store a regular expression at all: it would be either
a string or a substitution to \1 if the Postgres role is specified as
such.

Author: Jelte Fennema
Discussion: https://postgr.es/m/CAGECzQTkwELHUOAKhvdA+m3tWbUQySHHkExJV8GAZ1pwgbEgXg@mail.gmail.com

diff --git a/src/backend/libpq/hba.c b/src/backend/libpq/hba.c
index f5a2cc53be53d48caa9757a486a4f24177b98182..154b2857d2a7589693464de77b492f6e0b89ea23 100644 (file)
--- a/src/backend/libpq/hba.c
+++ b/src/backend/libpq/hba.c
@@ -2792,7 +2792,7 @@ parse_ident_line(TokenizedAuthLine *tok_line, int elevel)
    token = linitial(tokens);
 
    /* Copy the ident user token */
-   parsedline->token = copy_auth_token(token);
+   parsedline->system_user = copy_auth_token(token);
 
    /* Get the PG rolename token */
    field = lnext(tok_line->fields, field);
@@ -2800,13 +2800,13 @@ parse_ident_line(TokenizedAuthLine *tok_line, int elevel)
    tokens = lfirst(field);
    IDENT_MULTI_VALUE(tokens);
    token = linitial(tokens);
-   parsedline->pg_role = pstrdup(token->string);
+   parsedline->pg_user = pstrdup(token->string);
 
    /*
     * Now that the field validation is done, compile a regex from the user
     * token, if necessary.
     */
-   if (regcomp_auth_token(parsedline->token, file_name, line_num,
+   if (regcomp_auth_token(parsedline->system_user, file_name, line_num,
                           err_msg, elevel))
    {
        /* err_msg includes the error to report */
@@ -2819,12 +2819,12 @@ parse_ident_line(TokenizedAuthLine *tok_line, int elevel)
 /*
  * Process one line from the parsed ident config lines.
  *
- * Compare input parsed ident line to the needed map, pg_role and ident_user.
+ * Compare input parsed ident line to the needed map, pg_user and system_user.
  * *found_p and *error_p are set according to our results.
  */
 static void
 check_ident_usermap(IdentLine *identLine, const char *usermap_name,
-                   const char *pg_role, const char *ident_user,
+                   const char *pg_user, const char *system_user,
                    bool case_insensitive, bool *found_p, bool *error_p)
 {
    *found_p = false;
@@ -2835,7 +2835,7 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
        return;
 
    /* Match? */
-   if (token_has_regexp(identLine->token))
+   if (token_has_regexp(identLine->system_user))
    {
        /*
         * Process the system username as a regular expression that returns
@@ -2845,9 +2845,9 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
        int         r;
        regmatch_t  matches[2];
        char       *ofs;
-       char       *regexp_pgrole;
+       char       *expanded_pg_user;
 
-       r = regexec_auth_token(ident_user, identLine->token, 2, matches);
+       r = regexec_auth_token(system_user, identLine->system_user, 2, matches);
        if (r)
        {
            char        errstr[100];
@@ -2855,17 +2855,17 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
            if (r != REG_NOMATCH)
            {
                /* REG_NOMATCH is not an error, everything else is */
-               pg_regerror(r, identLine->token->regex, errstr, sizeof(errstr));
+               pg_regerror(r, identLine->system_user->regex, errstr, sizeof(errstr));
                ereport(LOG,
                        (errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
                         errmsg("regular expression match for \"%s\" failed: %s",
-                               identLine->token->string + 1, errstr)));
+                               identLine->system_user->string + 1, errstr)));
                *error_p = true;
            }
            return;
        }
 
-       if ((ofs = strstr(identLine->pg_role, "\\1")) != NULL)
+       if ((ofs = strstr(identLine->pg_user, "\\1")) != NULL)
        {
            int         offset;
 
@@ -2875,7 +2875,7 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
                ereport(LOG,
                        (errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
                         errmsg("regular expression \"%s\" has no subexpressions as requested by backreference in \"%s\"",
-                               identLine->token->string + 1, identLine->pg_role)));
+                               identLine->system_user->string + 1, identLine->pg_user)));
                *error_p = true;
                return;
            }
@@ -2884,18 +2884,18 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
             * length: original length minus length of \1 plus length of match
             * plus null terminator
             */
-           regexp_pgrole = palloc0(strlen(identLine->pg_role) - 2 + (matches[1].rm_eo - matches[1].rm_so) + 1);
-           offset = ofs - identLine->pg_role;
-           memcpy(regexp_pgrole, identLine->pg_role, offset);
-           memcpy(regexp_pgrole + offset,
-                  ident_user + matches[1].rm_so,
+           expanded_pg_user = palloc0(strlen(identLine->pg_user) - 2 + (matches[1].rm_eo - matches[1].rm_so) + 1);
+           offset = ofs - identLine->pg_user;
+           memcpy(expanded_pg_user, identLine->pg_user, offset);
+           memcpy(expanded_pg_user + offset,
+                  system_user + matches[1].rm_so,
                   matches[1].rm_eo - matches[1].rm_so);
-           strcat(regexp_pgrole, ofs + 2);
+           strcat(expanded_pg_user, ofs + 2);
        }
        else
        {
            /* no substitution, so copy the match */
-           regexp_pgrole = pstrdup(identLine->pg_role);
+           expanded_pg_user = pstrdup(identLine->pg_user);
        }
 
        /*
@@ -2904,15 +2904,15 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
         */
        if (case_insensitive)
        {
-           if (pg_strcasecmp(regexp_pgrole, pg_role) == 0)
+           if (pg_strcasecmp(expanded_pg_user, pg_user) == 0)
                *found_p = true;
        }
        else
        {
-           if (strcmp(regexp_pgrole, pg_role) == 0)
+           if (strcmp(expanded_pg_user, pg_user) == 0)
                *found_p = true;
        }
-       pfree(regexp_pgrole);
+       pfree(expanded_pg_user);
 
        return;
    }
@@ -2921,14 +2921,14 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
        /* Not regular expression, so make complete match */
        if (case_insensitive)
        {
-           if (pg_strcasecmp(identLine->pg_role, pg_role) == 0 &&
-               pg_strcasecmp(identLine->token->string, ident_user) == 0)
+           if (pg_strcasecmp(identLine->pg_user, pg_user) == 0 &&
+               pg_strcasecmp(identLine->system_user->string, system_user) == 0)
                *found_p = true;
        }
        else
        {
-           if (strcmp(identLine->pg_role, pg_role) == 0 &&
-               strcmp(identLine->token->string, ident_user) == 0)
+           if (strcmp(identLine->pg_user, pg_user) == 0 &&
+               strcmp(identLine->system_user->string, system_user) == 0)
                *found_p = true;
        }
    }
@@ -2938,20 +2938,20 @@ check_ident_usermap(IdentLine *identLine, const char *usermap_name,
 /*
  * Scan the (pre-parsed) ident usermap file line by line, looking for a match
  *
- * See if the user with ident username "auth_user" is allowed to act
- * as Postgres user "pg_role" according to usermap "usermap_name".
+ * See if the system user with ident username "system_user" is allowed to act as
+ * Postgres user "pg_user" according to usermap "usermap_name".
  *
  * Special case: Usermap NULL, equivalent to what was previously called
  * "sameuser" or "samerole", means don't look in the usermap file.
- * That's an implied map wherein "pg_role" must be identical to
- * "auth_user" in order to be authorized.
+ * That's an implied map wherein "pg_user" must be identical to
+ * "system_user" in order to be authorized.
  *
  * Iff authorized, return STATUS_OK, otherwise return STATUS_ERROR.
  */
 int
 check_usermap(const char *usermap_name,
-             const char *pg_role,
-             const char *auth_user,
+             const char *pg_user,
+             const char *system_user,
              bool case_insensitive)
 {
    bool        found_entry = false,
@@ -2961,17 +2961,17 @@ check_usermap(const char *usermap_name,
    {
        if (case_insensitive)
        {
-           if (pg_strcasecmp(pg_role, auth_user) == 0)
+           if (pg_strcasecmp(pg_user, system_user) == 0)
                return STATUS_OK;
        }
        else
        {
-           if (strcmp(pg_role, auth_user) == 0)
+           if (strcmp(pg_user, system_user) == 0)
                return STATUS_OK;
        }
        ereport(LOG,
                (errmsg("provided user name (%s) and authenticated user name (%s) do not match",
-                       pg_role, auth_user)));
+                       pg_user, system_user)));
        return STATUS_ERROR;
    }
    else
@@ -2981,7 +2981,7 @@ check_usermap(const char *usermap_name,
        foreach(line_cell, parsed_ident_lines)
        {
            check_ident_usermap(lfirst(line_cell), usermap_name,
-                               pg_role, auth_user, case_insensitive,
+                               pg_user, system_user, case_insensitive,
                                &found_entry, &error);
            if (found_entry || error)
                break;
@@ -2991,7 +2991,7 @@ check_usermap(const char *usermap_name,
    {
        ereport(LOG,
                (errmsg("no match in usermap \"%s\" for user \"%s\" authenticated as \"%s\"",
-                       usermap_name, pg_role, auth_user)));
+                       usermap_name, pg_user, system_user)));
    }
    return found_entry ? STATUS_OK : STATUS_ERROR;
 }
@@ -3073,7 +3073,7 @@ load_ident(void)
        foreach(parsed_line_cell, new_parsed_lines)
        {
            newline = (IdentLine *) lfirst(parsed_line_cell);
-           free_auth_token(newline->token);
+           free_auth_token(newline->system_user);
        }
        MemoryContextDelete(ident_context);
        return false;
@@ -3085,7 +3085,7 @@ load_ident(void)
        foreach(parsed_line_cell, parsed_ident_lines)
        {
            newline = (IdentLine *) lfirst(parsed_line_cell);
-           free_auth_token(newline->token);
+           free_auth_token(newline->system_user);
        }
    }
    if (parsed_ident_context != NULL)

diff --git a/src/backend/utils/adt/hbafuncs.c b/src/backend/utils/adt/hbafuncs.c
index 3cd83c77f8f6342ff88cb53f8bf2f42b978400a5..8a552ef8e9db6f107572fa59c0c126574a7de317 100644 (file)
--- a/src/backend/utils/adt/hbafuncs.c
+++ b/src/backend/utils/adt/hbafuncs.c
@@ -492,8 +492,8 @@ fill_ident_line(Tuplestorestate *tuple_store, TupleDesc tupdesc,
    if (ident != NULL)
    {
        values[index++] = CStringGetTextDatum(ident->usermap);
-       values[index++] = CStringGetTextDatum(ident->token->string);
-       values[index++] = CStringGetTextDatum(ident->pg_role);
+       values[index++] = CStringGetTextDatum(ident->system_user->string);
+       values[index++] = CStringGetTextDatum(ident->pg_user);
    }
    else
    {

diff --git a/src/include/libpq/hba.h b/src/include/libpq/hba.h
index 63b38180dcade711bc37caa7ec6550064f77f5a4..ed4d5e7962cbd0ec0685a27cb46b4e9d5246f147 100644 (file)
--- a/src/include/libpq/hba.h
+++ b/src/include/libpq/hba.h
@@ -142,8 +142,8 @@ typedef struct IdentLine
    int         linenumber;
 
    char       *usermap;
-   char       *pg_role;
-   AuthToken  *token;
+   AuthToken  *system_user;
+   char       *pg_user;
 } IdentLine;
 
 /*
@@ -172,7 +172,7 @@ extern bool load_ident(void);
 extern const char *hba_authname(UserAuth auth_method);
 extern void hba_getauthmethod(hbaPort *port);
 extern int check_usermap(const char *usermap_name,
-                         const char *pg_role, const char *auth_user,
+                         const char *pg_user, const char *system_user,
                          bool case_insensitive);
 extern HbaLine *parse_hba_line(TokenizedAuthLine *tok_line, int elevel);
 extern IdentLine *parse_ident_line(TokenizedAuthLine *tok_line, int elevel);