From 04248c2cfaa5a1728ef58fc8ca231fd1309ca694 Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Sun, 19 Dec 2010 19:52:08 +0100 Subject: [PATCH] s3-printing: reload shares after pcap cache fill MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Since commit eada8f8a, updates to the cups pcap cache are performed asynchronously - cups_cache_reload() forks a child process to request cups printer information and notify the parent smbd on completion. Currently printer shares are reloaded immediately following the call to cups_cache_reload(), this occurs prior to smbd receiving new cups pcap information from the child process. Such behaviour can result in stale print shares as outlined in bug 7836. This fix ensures print shares are only reloaded after new pcap data has been received. Pair-Programmed-With: Lars Müller --- source3/include/proto.h | 7 +++++-- source3/printing/load.c | 6 ++---- source3/printing/pcap.c | 17 +++++++++++++++-- source3/printing/pcap.h | 4 +++- source3/printing/print_cups.c | 40 ++++++++++++++++++++++++++++++++-------- source3/smbd/process.c | 3 ++- source3/smbd/server.c | 3 ++- source3/smbd/server_reload.c | 13 ++++++++----- source3/web/swat.c | 6 ++++-- 9 files changed, 73 insertions(+), 26 deletions(-) diff --git a/source3/include/proto.h b/source3/include/proto.h index 0775acd21da..91d3ef165e9 100644 --- a/source3/include/proto.h +++ b/source3/include/proto.h @@ -4062,7 +4062,9 @@ void notify_printer_sepfile(struct tevent_context *ev, /* The following definitions come from printing/pcap.c */ void pcap_cache_reload(struct tevent_context *ev, - struct messaging_context *msg_ctx); + struct messaging_context *msg_ctx, + void (*post_cache_fill_fn)(struct tevent_context *, + struct messaging_context *)); bool pcap_printername_ok(const char *printername); /* The following definitions come from printing/printing.c */ @@ -5399,7 +5401,8 @@ void server_messaging_context_free(void); struct event_context *smbd_event_context(void); struct messaging_context *smbd_messaging_context(void); struct memcache *smbd_memcache(void); -void reload_printers(struct messaging_context *msg_ctx); +void reload_printers(struct tevent_context *ev, + struct messaging_context *msg_ctx); bool reload_services(struct messaging_context *msg_ctx, int smb_sock, bool test); void exit_server(const char *const explanation); diff --git a/source3/printing/load.c b/source3/printing/load.c index 4f1bb88a996..66c3ffd22c0 100644 --- a/source3/printing/load.c +++ b/source3/printing/load.c @@ -54,14 +54,12 @@ static void add_auto_printers(void) } /*************************************************************************** -load automatic printer services +load automatic printer services from pre-populated pcap cache ***************************************************************************/ void load_printers(struct tevent_context *ev, struct messaging_context *msg_ctx) { - if (!pcap_cache_loaded()) { - pcap_cache_reload(ev, msg_ctx); - } + SMB_ASSERT(pcap_cache_loaded()); add_auto_printers(); diff --git a/source3/printing/pcap.c b/source3/printing/pcap.c index 1b8f46d8e71..be267bd116e 100644 --- a/source3/printing/pcap.c +++ b/source3/printing/pcap.c @@ -107,11 +107,14 @@ void pcap_cache_replace(const struct pcap_cache *pcache) } void pcap_cache_reload(struct tevent_context *ev, - struct messaging_context *msg_ctx) + struct messaging_context *msg_ctx, + void (*post_cache_fill_fn)(struct tevent_context *, + struct messaging_context *)) { const char *pcap_name = lp_printcapname(); bool pcap_reloaded = False; NTSTATUS status; + bool post_cache_fill_fn_handled = false; DEBUG(3, ("reloading printcap cache\n")); @@ -135,7 +138,13 @@ void pcap_cache_reload(struct tevent_context *ev, #ifdef HAVE_CUPS if (strequal(pcap_name, "cups")) { - pcap_reloaded = cups_cache_reload(ev, msg_ctx); + pcap_reloaded = cups_cache_reload(ev, msg_ctx, + post_cache_fill_fn); + /* + * cups_cache_reload() is async and calls post_cache_fill_fn() + * on successful completion + */ + post_cache_fill_fn_handled = true; goto done; } #endif @@ -174,6 +183,10 @@ done: if (!NT_STATUS_IS_OK(status)) { DEBUG(0, ("Failed to cleanup printer list!\n")); } + if ((post_cache_fill_fn_handled == false) + && (post_cache_fill_fn != NULL)) { + post_cache_fill_fn(ev, msg_ctx); + } } return; diff --git a/source3/printing/pcap.h b/source3/printing/pcap.h index 67f36d65981..7f8f7d2baf4 100644 --- a/source3/printing/pcap.h +++ b/source3/printing/pcap.h @@ -35,7 +35,9 @@ bool aix_cache_reload(void); /* The following definitions come from printing/print_cups.c */ bool cups_cache_reload(struct tevent_context *ev, - struct messaging_context *msg_ctx); + struct messaging_context *msg_ctx, + void (*post_cache_fill_fn)(struct tevent_context *, + struct messaging_context *)); bool cups_pull_comment_location(TALLOC_CTX *mem_ctx, const char *printername, char **comment, diff --git a/source3/printing/print_cups.c b/source3/printing/print_cups.c index a85fba89974..8c023ddb300 100644 --- a/source3/printing/print_cups.c +++ b/source3/printing/print_cups.c @@ -449,13 +449,22 @@ static bool cups_pcap_load_async(struct tevent_context *ev, _exit(0); } +struct cups_async_cb_args { + int pipe_fd; + struct event_context *event_ctx; + struct messaging_context *msg_ctx; + void (*post_cache_fill_fn)(struct event_context *, + struct messaging_context *); +}; + static void cups_async_callback(struct event_context *event_ctx, struct fd_event *event, uint16 flags, void *p) { TALLOC_CTX *frame = talloc_stackframe(); - int fd = *(int *)p; + struct cups_async_cb_args *cb_args = (struct cups_async_cb_args *)p; + int fd = cb_args->pipe_fd; struct pcap_cache *tmp_pcap_cache = NULL; DEBUG(5,("cups_async_callback: callback received for printer data. " @@ -549,28 +558,43 @@ static void cups_async_callback(struct event_context *event_ctx, /* And the systemwide pcap cache. */ pcap_cache_replace(local_pcap_copy); + + /* Caller may have requested post cache fill callback */ + if (cb_args->post_cache_fill_fn != NULL) { + cb_args->post_cache_fill_fn(cb_args->event_ctx, + cb_args->msg_ctx); + } } else { DEBUG(2,("cups_async_callback: failed to read a new " "printer list\n")); } close(fd); - TALLOC_FREE(p); + TALLOC_FREE(cb_args); TALLOC_FREE(cache_fd_event); } bool cups_cache_reload(struct tevent_context *ev, - struct messaging_context *msg_ctx) + struct messaging_context *msg_ctx, + void (*post_cache_fill_fn)(struct tevent_context *, + struct messaging_context *)) { - int *p_pipe_fd = TALLOC_P(NULL, int); + struct cups_async_cb_args *cb_args; + int *p_pipe_fd; - if (!p_pipe_fd) { + cb_args = TALLOC_P(NULL, struct cups_async_cb_args); + if (cb_args == NULL) { return false; } + cb_args->post_cache_fill_fn = post_cache_fill_fn; + cb_args->event_ctx = ev; + cb_args->msg_ctx = msg_ctx; + p_pipe_fd = &cb_args->pipe_fd; *p_pipe_fd = -1; /* Set up an async refresh. */ if (!cups_pcap_load_async(ev, msg_ctx, p_pipe_fd)) { + talloc_free(cb_args); return false; } if (!local_pcap_copy) { @@ -582,7 +606,7 @@ bool cups_cache_reload(struct tevent_context *ev, cups_async_callback(ev, NULL, EVENT_FD_READ, - (void *)p_pipe_fd); + (void *)cb_args); if (!local_pcap_copy) { return false; } @@ -599,10 +623,10 @@ bool cups_cache_reload(struct tevent_context *ev, NULL, *p_pipe_fd, EVENT_FD_READ, cups_async_callback, - (void *)p_pipe_fd); + (void *)cb_args); if (!cache_fd_event) { close(*p_pipe_fd); - TALLOC_FREE(p_pipe_fd); + TALLOC_FREE(cb_args); return false; } } diff --git a/source3/smbd/process.c b/source3/smbd/process.c index 150b2dd2cb1..2992576702a 100644 --- a/source3/smbd/process.c +++ b/source3/smbd/process.c @@ -2259,7 +2259,8 @@ static void check_reload(struct smbd_server_connection *sconn, time_t t) || (t-last_printer_reload_time < 0) ) { DEBUG( 3,( "Printcap cache time expired.\n")); - reload_printers(sconn->msg_ctx); + pcap_cache_reload(server_event_context(), + sconn->msg_ctx, &reload_printers); last_printer_reload_time = t; } } diff --git a/source3/smbd/server.c b/source3/smbd/server.c index 1b9e793e4c5..16aa055b353 100644 --- a/source3/smbd/server.c +++ b/source3/smbd/server.c @@ -1238,7 +1238,8 @@ extern void build_options(bool screen); } /* Publish nt printers, this requires a working winreg pipe */ - reload_printers(smbd_messaging_context()); + pcap_cache_reload(server_event_context(), smbd_messaging_context(), + &reload_printers); /* only start the background queue daemon if we are running as a daemon -- bad things will happen if diff --git a/source3/smbd/server_reload.c b/source3/smbd/server_reload.c index 38d1f3a354a..2b74e7a0d49 100644 --- a/source3/smbd/server_reload.c +++ b/source3/smbd/server_reload.c @@ -25,11 +25,13 @@ #include "smbd/globals.h" #include "librpc/gen_ndr/messaging.h" #include "nt_printing.h" +#include "printing/pcap.h" /**************************************************************************** - Reload printers + purge stale printers and reload from pre-populated pcap cache **************************************************************************/ -void reload_printers(struct messaging_context *msg_ctx) +void reload_printers(struct tevent_context *ev, + struct messaging_context *msg_ctx) { struct auth_serversupplied_info *server_info = NULL; struct spoolss_PrinterInfo2 *pinfo2 = NULL; @@ -40,7 +42,8 @@ void reload_printers(struct messaging_context *msg_ctx) NTSTATUS status; bool skip = false; - pcap_cache_reload(server_event_context(), msg_ctx); + SMB_ASSERT(pcap_cache_loaded()); + DEBUG(10, ("reloading printer services from pcap cache\n")); status = make_server_info_system(talloc_tos(), &server_info); if (!NT_STATUS_IS_OK(status)) { @@ -79,7 +82,7 @@ void reload_printers(struct messaging_context *msg_ctx) } } - load_printers(server_event_context(), msg_ctx); + load_printers(ev, msg_ctx); TALLOC_FREE(server_info); } @@ -111,7 +114,7 @@ bool reload_services(struct messaging_context *msg_ctx, int smb_sock, ret = lp_load(get_dyn_CONFIGFILE(), False, False, True, True); - reload_printers(msg_ctx); + pcap_cache_reload(server_event_context(), msg_ctx, &reload_printers); /* perhaps the config filename is now set */ if (!test) diff --git a/source3/web/swat.c b/source3/web/swat.c index bb3f3f974c6..1cbecd4675a 100644 --- a/source3/web/swat.c +++ b/source3/web/swat.c @@ -491,7 +491,8 @@ static int save_reload(int snum) return 0; } iNumNonAutoPrintServices = lp_numservices(); - load_printers(server_event_context(), server_messaging_context()); + pcap_cache_reload(server_event_context(), server_messaging_context(), + &load_printers); return 1; } @@ -1435,7 +1436,8 @@ const char *lang_msg_rotate(TALLOC_CTX *ctx, const char *msgid) reopen_logs(); load_interfaces(); iNumNonAutoPrintServices = lp_numservices(); - load_printers(server_event_context(), server_messaging_context()); + pcap_cache_reload(server_event_context(), server_messaging_context(), + &load_printers); cgi_setup(get_dyn_SWATDIR(), !demo_mode); -- 2.11.4.GIT