diff -up cups-2.2.0/cups/auth.c.resolv_reload cups-2.2.0/cups/auth.c
--- cups-2.2.0/cups/auth.c.resolv_reload 2017-05-09 10:36:47.764075800 +0200
+++ cups-2.2.0/cups/auth.c 2017-05-09 10:40:50.074052694 +0200
@@ -519,6 +519,18 @@ cups_gss_getname(
DEBUG_printf(("7cups_gss_getname(http=%p, service_name=\"%s\")", http,
service_name));
+#ifdef HAVE_RES_INIT
+ /*
+ * Check if /etc/resolv.conf is modified.
+ * If so, reload resolver.
+ */
+
+ dns_resolver_reload_rv retval;
+
+ retval = dnsReloadResolver();
+ if (retval.status == DNS_RESOLVER_RELOAD_ERROR)
+ DEBUG_printf(("1cups_gss_getname: dnsReloadResolver() failed - %s.", strerror(retval.errnum)));
+#endif /* HAVE_RES_INIT */
/*
* Get the hostname...
diff -up cups-2.2.0/cups/http-addr.c.resolv_reload cups-2.2.0/cups/http-addr.c
--- cups-2.2.0/cups/http-addr.c.resolv_reload 2017-05-09 10:36:58.094989545 +0200
+++ cups-2.2.0/cups/http-addr.c 2017-05-09 10:43:51.958516333 +0200
@@ -361,6 +361,20 @@ httpAddrLookup(
#ifdef HAVE_RES_INIT
/*
+ * Check if /etc/resolv.conf is modified.
+ * If so, reload resolver and set need_res_init to 0.
+ */
+
+ dns_resolver_reload_rv retval;
+
+ retval = dnsReloadResolver();
+
+ if (retval.status == DNS_RESOLVER_RELOAD_RELOADED && cg->need_res_init == 1)
+ cg->need_res_init = 0;
+
+ if (retval.status == DNS_RESOLVER_RELOAD_ERROR)
+ DEBUG_printf(("1httpAddrLookup: dnsReloadResolver() failed - %s.", strerror(retval.errnum)));
+ /*
* STR #2920: Initialize resolver after failure in cups-polld
*
* If the previous lookup failed, re-initialize the resolver to prevent
diff -up cups-2.2.0/cups/http-addrlist.c.resolv_reload cups-2.2.0/cups/http-addrlist.c
--- cups-2.2.0/cups/http-addrlist.c.resolv_reload 2017-05-09 10:37:03.834941621 +0200
+++ cups-2.2.0/cups/http-addrlist.c 2017-05-09 10:45:10.426832540 +0200
@@ -483,6 +483,20 @@ httpAddrGetList(const char *hostname, /*
#ifdef HAVE_RES_INIT
/*
+ * Check if /etc/resolv.conf is modified.
+ * If so, reload resolver and set cg->need_res_init to 0
+ */
+
+ dns_resolver_reload_rv retval;
+
+ retval = dnsReloadResolver();
+
+ if (retval.status == DNS_RESOLVER_RELOAD_RELOADED && cg->need_res_init == 1)
+ cg->need_res_init = 0;
+
+ if (retval.status == DNS_RESOLVER_RELOAD_ERROR)
+ DEBUG_printf(("1httpAddrGetList: dnsReloadResolver() failed - %s.", strerror(retval.errnum)));
+ /*
* STR #2920: Initialize resolver after failure in cups-polld
*
* If the previous lookup failed, re-initialize the resolver to prevent
diff -up cups-2.2.0/cups/http.c.resolv_reload cups-2.2.0/cups/http.c
--- cups-2.2.0/cups/http.c.resolv_reload 2017-05-09 10:37:23.282779246 +0200
+++ cups-2.2.0/cups/http.c 2017-05-09 10:47:21.406691147 +0200
@@ -107,7 +107,9 @@ static const char * const http_fields[]
"Allow",
"Server"
};
-
+#ifdef HAVE_RES_INIT
+time_t resolv_conf_modtime = 0;
+#endif /* HAVE_RES_INIT */
/*
* 'httpAcceptConnection()' - Accept a new HTTP client connection from the
@@ -4811,3 +4813,107 @@ http_write_chunk(http_t *http, /* I
return (bytes);
}
+
+#ifdef HAVE_RES_INIT
+/*
+ * Function to check modification time of resolv.conf.
+ * If time is changed, it reloads resolver.
+ * If /etc/resolv.conf doesn't exist, it tries to reload resolver with local nameserver, if it wasn't reloaded before
+ * If even reloading resolver with local nameserver doesn't work, it ends with error.
+ * Global variable resolv_conf_modtime is set to -1 before the first call of this function - this is for prevention of resolver's reloading when cupsd is just started and resolv.conf exists - cupsd has current configuration in that case.
+ */
+
+dns_resolver_reload_rv
+dnsReloadResolver()
+{
+ dns_resolver_reload_rv retval, lstat_retval, stat_retval, res_init_retval;
+ struct stat resolv_conf_stat, resolv_conf_lstat, resolv_conf_status;
+ retval.status = DNS_RESOLVER_RELOAD_OK;
+ retval.errnum = 0;
+ stat_retval.errnum = 0;
+ lstat_retval.errnum = 0;
+ res_init_retval.errnum = 0;
+
+ /* Variable to store /etc/resolv.conf modification time - initialized by actual time*/
+ static time_t resolv_conf_modtime = -1;
+
+ /* This part of code is to ensure we get modification time of symlink and original file - we will decide which is newer later */
+ stat_retval.status = stat(DNS_RESOLV_CONF_PATH, &resolv_conf_stat);
+ stat_retval.errnum = errno;
+ lstat_retval.status = lstat(DNS_RESOLV_CONF_PATH, &resolv_conf_lstat);
+ lstat_retval.errnum = errno;
+
+ /* symlink /etc/resolv.conf or original file couldn't be stated because it doesn't exist, try resolver on localhost
+ * Covers cases:
+ * - resolv.conf and original file existed and it doesn't now - resolv_conf_modtime has different value than 0 - reload resolver with local nameserver
+ * - resolv.conf and original file didn't exist and still doesn't exist - resolv_conf_modtime is set to 0 - do nothing
+ */
+ if (stat_retval.status == -1 && lstat_retval.status == -1 && stat_retval.errnum == ENOENT && lstat_retval.errnum == ENOENT)
+ {
+ /* if resolv_conf_modtime is set to 0, it means previous reload was for resolver with local nameserver - no need to reload again */
+ if (resolv_conf_modtime != 0)
+ {
+ res_init_retval.status = res_init();
+ res_init_retval.errnum = errno;
+ if (res_init_retval.status == 0)
+ {
+ resolv_conf_modtime = 0;
+ retval.status = DNS_RESOLVER_RELOAD_RELOADED;
+ }
+ else
+ retval.status = res_init_retval.status;
+
+ retval.errnum = res_init_retval.errnum;
+ }
+ else
+ {
+ retval.status = DNS_RESOLVER_RELOAD_OK;
+ retval.errnum = ENOENT;
+ }
+
+ return (retval);
+ }
+
+ /* If stat ends with different errno, return status - it should return both statuses and errnos, but for simplification it returns only stat */
+ if (stat_retval.status == -1 && lstat_retval.status == -1)
+ {
+ retval.errnum = stat_retval.errnum;
+ retval.status = stat_retval.status;
+ return (retval);
+ }
+
+ /* Here we compare modification times from lstat and stat to decide which is newer - if they are equal, lstat modification time is used. We are checking only stat() errno, because case with errors in both lstat() and stat() functions is checked before */
+ if (stat_retval.errnum == 0)
+ if (resolv_conf_stat.st_mtime > resolv_conf_lstat.st_mtime)
+ resolv_conf_status = resolv_conf_stat;
+ else
+ resolv_conf_status = resolv_conf_lstat;
+ else
+ resolv_conf_status = resolv_conf_lstat;
+
+ /* If /etc/resolv.conf exists and modification times are different, reload resolver.
+ * Covers cases:
+ * - resolv.conf or original file exists and it was modified - resolv_conf_modtime has different value than resolv_conf_status.st_mtime - reload resolver with nameserver from /etc/resolv.conf
+ * - resolv.conf or original file didn't exist and it does now - resolv_conf_modtime is set to 0 and resolv_conf_status.st_mtime has value - reload resolver with nameserver form /etc/resolv.conf
+ * - resolv.conf or original file exists and it wasn't modified - resolv_conf_modtime is equal to resolv_conf_status.st_mtime - do nothing
+ */
+ if (resolv_conf_status.st_mtime != resolv_conf_modtime)
+ {
+ res_init_retval.status = res_init();
+ res_init_retval.errnum = errno;
+ if (res_init_retval.status == 0)
+ {
+ retval.status = DNS_RESOLVER_RELOAD_RELOADED;
+ }
+ else
+ retval.status = res_init_retval.status;
+
+ retval.errnum = res_init_retval.errnum;
+ }
+
+ resolv_conf_modtime = resolv_conf_status.st_mtime;
+
+ return (retval);
+}
+#endif /* HAVE_RES_INIT */
+
diff -up cups-2.2.0/cups/http.h.resolv_reload cups-2.2.0/cups/http.h
--- cups-2.2.0/cups/http.h.resolv_reload 2017-05-09 10:37:41.108630413 +0200
+++ cups-2.2.0/cups/http.h 2017-05-09 12:20:16.115333557 +0200
@@ -55,6 +55,12 @@ typedef off_t ssize_t; /* @private@ */
# define SO_PEERCRED LOCAL_PEERCRED
# endif /* LOCAL_PEERCRED && !SO_PEERCRED */
# endif /* WIN32 */
+# ifdef HAVE_RES_INIT
+# include <sys/stat.h>
+# include <unistd.h>
+# include <arpa/nameser.h>
+# include <resolv.h>
+# endif /* HAVE_RES_INIT */
/*
@@ -95,6 +101,13 @@ extern "C" {
#endif /* AF_INET6 && !s6_addr32 */
+#ifdef HAVE_RES_INIT
+/*
+ * Global variable for storing old modification time of resolv.conf
+ */
+ extern time_t resolv_conf_modtime;
+#endif /* HAVE_RES_INIT */
+
/*
* Limits...
*/
@@ -103,6 +116,9 @@ extern "C" {
# define HTTP_MAX_HOST 256 /* Max length of hostname string */
# define HTTP_MAX_BUFFER 2048 /* Max length of data buffer */
# define HTTP_MAX_VALUE 256 /* Max header field value length */
+# ifdef HAVE_RES_INIT
+# define DNS_RESOLV_CONF_PATH "/etc/resolv.conf" /* Path to resolv.conf */
+# endif /* HAVE_RES_INIT */
/*
@@ -406,6 +422,15 @@ typedef enum http_version_e /**** HTTP
# endif /* !_CUPS_NO_DEPRECATED */
} http_version_t;
+#ifdef HAVE_RES_INIT
+typedef enum dns_resolver_reload_e
+{
+ DNS_RESOLVER_RELOAD_ERROR = -1,
+ DNS_RESOLVER_RELOAD_OK = 0,
+ DNS_RESOLVER_RELOAD_RELOADED = 1
+} dns_resolver_reload_t;
+#endif /* HAVE_RES_INIT */
+
typedef union _http_addr_u /**** Socket address union, which
**** makes using IPv6 and other
**** address types easier and
@@ -444,6 +469,13 @@ typedef struct http_credential_s /**** H
typedef int (*http_timeout_cb_t)(http_t *http, void *user_data);
/**** HTTP timeout callback @since CUPS 1.5/macOS 10.7@ ****/
+#ifdef HAVE_RES_INIT
+typedef struct dns_resolver_reload_retval
+{
+ dns_resolver_reload_t status;
+ int errnum;
+} dns_resolver_reload_rv;
+#endif /* HAVE_RES_INIT */
/*
@@ -590,6 +622,10 @@ extern http_version_t httpGetVersion(htt
extern int httpReconnect2(http_t *http, int msec, int *cancel)
_CUPS_API_1_6;
+/**** Prototype of function to check modification time of /etc/resolv.conf ****/
+#ifdef HAVE_RES_INIT
+extern dns_resolver_reload_rv dnsReloadResolver();
+#endif /* HAVE_RES_INIT */
/**** New in CUPS 1.7/macOS 10.9 ****/
extern http_t *httpAcceptConnection(int fd, int blocking)
diff -up cups-2.2.0/cups/http-support.c.resolv_reload cups-2.2.0/cups/http-support.c
--- cups-2.2.0/cups/http-support.c.resolv_reload 2017-05-09 10:38:11.314378218 +0200
+++ cups-2.2.0/cups/http-support.c 2017-05-09 12:21:40.455565953 +0200
@@ -2258,6 +2258,18 @@ http_resolve_cb(
http_addrlist_t *addrlist, /* List of addresses */
*addr; /* Current address */
+#ifdef HAVE_RES_INIT
+ /*
+ * Check if resolv.conf is modified, if so, reload resolver
+ */
+
+ dns_resolver_reload_rv retval;
+
+ retval = dnsReloadResolver();
+ if (retval.status == DNS_RESOLVER_RELOAD_ERROR)
+ DEBUG_printf(("1http_resolve_cb: dnsReloadResolver() failed - %s.", strerror(retval.errnum)));
+#endif /* HAVE_RES_INIT */
+
DEBUG_printf(("5http_resolve_cb: Looking up \"%s\".", hostTarget));
snprintf(fqdn, sizeof(fqdn), "%d", ntohs(port));
diff -up cups-2.2.0/scheduler/conf.c.resolv_reload cups-2.2.0/scheduler/conf.c
--- cups-2.2.0/scheduler/conf.c.resolv_reload 2017-05-09 10:38:29.869223299 +0200
+++ cups-2.2.0/scheduler/conf.c 2017-05-09 12:22:40.442020000 +0200
@@ -937,6 +937,15 @@ cupsdReadConfiguration(void)
if (!RemotePort)
BrowseLocalProtocols = 0; /* Disable sharing - no remote access */
+#ifdef HAVE_RES_INIT
+ dns_resolver_reload_rv retval; /* Return status of dnsReloadResolver() */
+
+ retval = dnsReloadResolver();
+
+ if (retval.status == DNS_RESOLVER_RELOAD_ERROR)
+ syslog(LOG_LPR, "1cupsdReadConfiguration: dnsReloadResolver() failed - %s.", strerror(retval.errnum));
+#endif /* HAVE_RES_INIT */
+
/*
* See if the ServerName is an IP address...
*/
diff -up cups-2.2.0/scheduler/main.c.resolv_reload cups-2.2.0/scheduler/main.c
--- cups-2.2.0/scheduler/main.c.resolv_reload 2017-05-09 10:38:37.699157925 +0200
+++ cups-2.2.0/scheduler/main.c 2017-05-09 12:23:36.280514244 +0200
@@ -136,6 +136,14 @@ main(int argc, /* I - Number of comm
long tmo_delay; /* Time before it must be called */
#endif /* HAVE_AVAHI */
+#ifdef HAVE_RES_INIT
+ dns_resolver_reload_rv retval; /* Return status from dnsReloadResolver() */
+
+ retval = dnsReloadResolver();
+ if (retval.status == DNS_RESOLVER_RELOAD_ERROR)
+ fprintf(stderr, "cupsd: Cannot reload a resolver - %s , using old configuration now.\n", strerror(retval.errnum));
+#endif /* HAVE_RES_INIT */
+
#ifdef HAVE_GETEUID
/*
* Check for setuid invocation, which we do not support!