From 313f56ce2d1b9dfd3483e4f39611baa27852835a Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Fri, 14 Jun 2019 18:02:26 -0400 Subject: [PATCH] Tweak libpq's PQhost, PQhostaddr, and psql's \connect Fixes some problems introduced by 6e5f8d489acc: * When reusing conninfo data from the previous connection in \connect, the host address should only be reused if it was specified as hostaddr; if it wasn't, then 'host' is resolved afresh. We were reusing the same IP address, which ignores a possible DNS change as well as any other addresses that the name resolves to than the one that was used in the original connection. * PQhost, PQhostaddr: Don't present user-specified hostaddr when we have an inet_net_ntop-produced equivalent address. The latter has been put in canonical format, which is cleaner (so it produces "127.0.0.1" when given "host=2130706433", for example). * Document the hostaddr-reusing aspect of \connect. * Fix some code comments Author: Fabien Coelho Reported-by: Noah Misch Discussion: https://postgr.es/m/20190527203713.GA58392@gust.leadboat.com --- doc/src/sgml/ref/psql-ref.sgml | 3 +++ src/bin/psql/command.c | 41 ++++++++++++++++++++++++------- src/interfaces/libpq/fe-connect.c | 20 ++++++--------- 3 files changed, 43 insertions(+), 21 deletions(-) diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml index b86764003d..c6c20de243 100644 --- a/doc/src/sgml/ref/psql-ref.sgml +++ b/doc/src/sgml/ref/psql-ref.sgml @@ -911,6 +911,9 @@ testdb=> host or port as - is equivalent to omitting that parameter. + If hostaddr was specified in the original + connection's conninfo, that address is reused + for the new connection (disregarding any other host specification). diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c index 695d6ba9f1..6263f8a779 100644 --- a/src/bin/psql/command.c +++ b/src/bin/psql/command.c @@ -2870,6 +2870,26 @@ param_is_newly_set(const char *old_val, const char *new_val) return false; } +/* return whether the connection has 'hostaddr' in its conninfo */ +static bool +has_hostaddr(PGconn *conn) +{ + bool used = false; + PQconninfoOption *ciopt = PQconninfo(conn); + + for (PQconninfoOption *p = ciopt; p->keyword != NULL; p++) + { + if (strcmp(p->keyword, "hostaddr") == 0 && p->val != NULL) + { + used = true; + break; + } + } + + PQconninfoFree(ciopt); + return used; +} + /* * do_connect -- handler for \connect * @@ -2929,24 +2949,24 @@ do_connect(enum trivalue reuse_previous_specification, port = NULL; } - /* grab missing values from the old connection */ + /* + * Grab missing values from the old connection. If we grab host (or host + * is the same as before) and hostaddr was set, grab that too. + */ if (reuse_previous) { if (!user) user = PQuser(o_conn); - if (host && strcmp(host, PQhost(o_conn)) == 0) + if (host && strcmp(host, PQhost(o_conn)) == 0 && + has_hostaddr(o_conn)) { - /* - * if we are targeting the same host, reuse its hostaddr for - * consistency - */ hostaddr = PQhostaddr(o_conn); } if (!host) { host = PQhost(o_conn); - /* also set hostaddr for consistency */ - hostaddr = PQhostaddr(o_conn); + if (has_hostaddr(o_conn)) + hostaddr = PQhostaddr(o_conn); } if (!port) port = PQport(o_conn); @@ -3129,7 +3149,10 @@ do_connect(enum trivalue reuse_previous_specification, char *host = PQhost(pset.db); char *hostaddr = PQhostaddr(pset.db); - /* If the host is an absolute path, the connection is via socket */ + /* + * If the host is an absolute path, the connection is via socket + * unless overridden by hostaddr + */ if (is_absolute_path(host)) { if (hostaddr && *hostaddr) diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c index e58fa6742a..c800d7921e 100644 --- a/src/interfaces/libpq/fe-connect.c +++ b/src/interfaces/libpq/fe-connect.c @@ -1536,9 +1536,7 @@ getHostaddr(PGconn *conn, char *host_addr, int host_addr_len) { struct sockaddr_storage *addr = &conn->raddr.addr; - if (conn->connhost[conn->whichhost].type == CHT_HOST_ADDRESS) - strlcpy(host_addr, conn->connhost[conn->whichhost].hostaddr, host_addr_len); - else if (addr->ss_family == AF_INET) + if (addr->ss_family == AF_INET) { if (inet_net_ntop(AF_INET, &((struct sockaddr_in *) addr)->sin_addr.s_addr, @@ -6463,6 +6461,10 @@ PQhost(const PGconn *conn) if (conn->connhost != NULL) { + /* + * Return the verbatim host value provided by user, or hostaddr in its + * lack. + */ if (conn->connhost[conn->whichhost].host != NULL && conn->connhost[conn->whichhost].host[0] != '\0') return conn->connhost[conn->whichhost].host; @@ -6480,15 +6482,9 @@ PQhostaddr(const PGconn *conn) if (!conn) return NULL; - if (conn->connhost != NULL) - { - if (conn->connhost[conn->whichhost].hostaddr != NULL && - conn->connhost[conn->whichhost].hostaddr[0] != '\0') - return conn->connhost[conn->whichhost].hostaddr; - - if (conn->connip != NULL) - return conn->connip; - } + /* Return the parsed IP address */ + if (conn->connhost != NULL && conn->connip != NULL) + return conn->connip; return ""; }