On Tue, Jul 15, 2014 at 10:45 PM, Magnus Hagander <mag...@hagander.net> wrote: > On Wed, Jul 2, 2014 at 10:52 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: >> I wrote: >>> In short, maybe we ought to invent a new category PGC_SU_BACKEND (not >>> wedded to this spelling), which is to PGC_BACKEND as PGC_SUSET is to >>> PGC_USERSET, ie same when-it-can-be-changed behavior but only superusers >>> are allowed to change it. I don't have any objection to making these two >>> settings only adjustable by superusers --- I just don't want to give up >>> the existing timing restrictions for them. >> >> Another idea would be to get rid of PGC_SUSET as a separate category, and >> instead have a superuser-only bit in the GUC flags, which would apply to >> all categories. This would be a bit more orthogonal, though likely a >> much more invasive change. > > That could become interesting in the futuren ow that we have ALTER > SYSTEM SET. It could allow a non-superuser to make persistent > configuration changes. Now, I'm not sure we actually *want* that > though... But having it as a separate bit would make it possible for > ALTER SYSTEM SET to say that for example regular users would be able > to change work_mem persistently. But if we want to go down that route, > we might need a more fine grained permissions model than just > superuser vs non-superuser... > > I think going with the PGC_SU_BACKEND is the right choice at this > time, until we have an actual usecase for the other :)
Yep, the attached patch introduces PGC_SU_BACKEND and changes the contexts of log_connections and log_disconnections to PGC_SU_BACKEND. Review? Regards, -- Fujii Masao
*** a/src/backend/tcop/postgres.c --- b/src/backend/tcop/postgres.c *************** *** 3258,3264 **** get_stats_option_name(const char *arg) * argv[0] is ignored in either case (it's assumed to be the program name). * * ctx is PGC_POSTMASTER for secure options, PGC_BACKEND for insecure options ! * coming from the client, or PGC_SUSET for insecure options coming from * a superuser client. * * If a database name is present in the command line arguments, it's --- 3258,3264 ---- * argv[0] is ignored in either case (it's assumed to be the program name). * * ctx is PGC_POSTMASTER for secure options, PGC_BACKEND for insecure options ! * coming from the client, or PGC_SU_BACKEND for insecure options coming from * a superuser client. * * If a database name is present in the command line arguments, it's *** a/src/backend/utils/init/postinit.c --- b/src/backend/utils/init/postinit.c *************** *** 957,963 **** process_startup_options(Port *port, bool am_superuser) GucContext gucctx; ListCell *gucopts; ! gucctx = am_superuser ? PGC_SUSET : PGC_BACKEND; /* * First process any command-line switches that were included in the --- 957,963 ---- GucContext gucctx; ListCell *gucopts; ! gucctx = am_superuser ? PGC_SU_BACKEND : PGC_BACKEND; /* * First process any command-line switches that were included in the *** a/src/backend/utils/misc/guc.c --- b/src/backend/utils/misc/guc.c *************** *** 512,517 **** const char *const GucContext_Names[] = --- 512,518 ---- /* PGC_INTERNAL */ "internal", /* PGC_POSTMASTER */ "postmaster", /* PGC_SIGHUP */ "sighup", + /* PGC_SU_BACKEND */ "superuser-backend", /* PGC_BACKEND */ "backend", /* PGC_SUSET */ "superuser", /* PGC_USERSET */ "user" *************** *** 910,916 **** static struct config_bool ConfigureNamesBool[] = NULL, NULL, NULL }, { ! {"log_connections", PGC_BACKEND, LOGGING_WHAT, gettext_noop("Logs each successful connection."), NULL }, --- 911,917 ---- NULL, NULL, NULL }, { ! {"log_connections", PGC_SU_BACKEND, LOGGING_WHAT, gettext_noop("Logs each successful connection."), NULL }, *************** *** 919,925 **** static struct config_bool ConfigureNamesBool[] = NULL, NULL, NULL }, { ! {"log_disconnections", PGC_BACKEND, LOGGING_WHAT, gettext_noop("Logs end of a session, including duration."), NULL }, --- 920,926 ---- NULL, NULL, NULL }, { ! {"log_disconnections", PGC_SU_BACKEND, LOGGING_WHAT, gettext_noop("Logs end of a session, including duration."), NULL }, *************** *** 5681,5696 **** set_config_option(const char *name, const char *value, * signals to individual backends only. */ break; case PGC_BACKEND: if (context == PGC_SIGHUP) { /* ! * If a PGC_BACKEND parameter is changed in the config file, ! * we want to accept the new value in the postmaster (whence ! * it will propagate to subsequently-started backends), but ! * ignore it in existing backends. This is a tad klugy, but ! * necessary because we don't re-read the config file during ! * backend start. * * In EXEC_BACKEND builds, this works differently: we load all * nondefault settings from the CONFIG_EXEC_PARAMS file during --- 5682,5706 ---- * signals to individual backends only. */ break; + case PGC_SU_BACKEND: + if (context == PGC_BACKEND) + { + ereport(elevel, + (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), + errmsg("permission denied to set parameter \"%s\"", + name))); + return 0; + } case PGC_BACKEND: if (context == PGC_SIGHUP) { /* ! * If a PGC_SU_BACKEND or PGC_BACKEND parameter is changed in ! * the config file, we want to accept the new value in the ! * postmaster (whence it will propagate to subsequently-started ! * backends), but ignore it in existing backends. This is a tad ! * klugy, but necessary because we don't re-read the config file ! * during backend start. * * In EXEC_BACKEND builds, this works differently: we load all * nondefault settings from the CONFIG_EXEC_PARAMS file during *************** *** 5709,5716 **** set_config_option(const char *name, const char *value, return -1; #endif } ! else if (context != PGC_POSTMASTER && context != PGC_BACKEND && ! source != PGC_S_CLIENT) { ereport(elevel, (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM), --- 5719,5726 ---- return -1; #endif } ! else if (context != PGC_POSTMASTER && context != PGC_SU_BACKEND && ! context != PGC_SU_BACKEND && source != PGC_S_CLIENT) { ereport(elevel, (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM), *************** *** 8353,8360 **** read_nondefault_variables(void) GucContext varscontext; /* ! * Assert that PGC_BACKEND case in set_config_option() will do the right ! * thing. */ Assert(IsInitProcessingMode()); --- 8363,8370 ---- GucContext varscontext; /* ! * Assert that PGC_SU_BACKEND and PGC_BACKEND case in set_config_option() ! * will do the right thing. */ Assert(IsInitProcessingMode()); *** a/src/include/utils/guc.h --- b/src/include/utils/guc.h *************** *** 36,47 **** * certain point in their main loop. It's safer to wait than to read a * file asynchronously.) * ! * BACKEND options can only be set at postmaster startup, from the * configuration file, or by client request in the connection startup ! * packet (e.g., from libpq's PGOPTIONS variable). Furthermore, an ! * already-started backend will ignore changes to such an option in the ! * configuration file. The idea is that these options are fixed for a ! * given backend once it's started, but they can vary across backends. * * SUSET options can be set at postmaster startup, with the SIGHUP * mechanism, or from SQL if you're a superuser. --- 36,52 ---- * certain point in their main loop. It's safer to wait than to read a * file asynchronously.) * ! * SU_BACKEND options can only be set at postmaster startup, from the * configuration file, or by client request in the connection startup ! * packet (e.g., from libpq's PGOPTIONS variable) if you're a superuser. ! * Furthermore, an already-started backend will ignore changes to ! * such an option in the configuration file. The idea is that these options ! * are fixed for a given backend once it's started, but they can vary ! * across backends. ! * ! * BACKEND options are the same as SU_BACKEND ones, but they can ! * be set by client request in the connection startup packet even when ! * you're not a superuser. * * SUSET options can be set at postmaster startup, with the SIGHUP * mechanism, or from SQL if you're a superuser. *************** *** 53,58 **** typedef enum --- 58,64 ---- PGC_INTERNAL, PGC_POSTMASTER, PGC_SIGHUP, + PGC_SU_BACKEND, PGC_BACKEND, PGC_SUSET, PGC_USERSET
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