[PATCH 0/3] conf, log: Fix regression in usage() printing

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* [PATCH 0/3] conf, log: Fix regression in usage() printing
@ 2024-05-29  9:04 David Gibson
  2024-05-29  9:04 ` [PATCH 1/3] conf: Remove unhelpful usage() wrapper David Gibson
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: David Gibson @ 2024-05-29  9:04 UTC (permalink / raw)
  To: passt-dev, Stefano Brivio; +Cc: erik.sjolund, David Gibson

Erik Sjölund pointed out a regression where we're no long printing the
--help message to stdout, but to stderr instead.

I'm not actually sure what caused the regression, but it was made
possible by the fact that the original fix was pretty strange to begin
with.  It introduced some hacks to force the logging subsystem to go
to stdout, which have presumably failed in some subtle way.  But,
there's really no reason to run usage() through the logging subsystem
in the first place - it just adds complexity.

Link: https://bugs.passt.top/show_bug.cgi?id=90
Link: https://bugs.passt.top/show_bug.cgi?id=52

David Gibson (3):
  conf: Remove unhelpful usage() wrapper
  conf: Don't print usage via the logging subsystem
  log: Remove log_to_stdout option

 conf.c | 329 ++++++++++++++++++++++++++++-----------------------------
 log.c  |   8 +-
 log.h  |   1 -
 3 files changed, 163 insertions(+), 175 deletions(-)

-- 
2.45.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 1/3] conf: Remove unhelpful usage() wrapper
  2024-05-29  9:04 [PATCH 0/3] conf, log: Fix regression in usage() printing David Gibson
@ 2024-05-29  9:04 ` David Gibson
  2024-05-29  9:04 ` [PATCH 2/3] conf: Don't print usage via the logging subsystem David Gibson
  2024-05-29  9:04 ` [PATCH 3/3] log: Remove log_to_stdout option David Gibson
  2 siblings, 0 replies; 6+ messages in thread
From: David Gibson @ 2024-05-29  9:04 UTC (permalink / raw)
  To: passt-dev, Stefano Brivio; +Cc: erik.sjolund, David Gibson

usage() does nothing but call print_usage() with EXIT_FAILURE as a
parameter.  It's no more complex to just give that parameter at the single
call site.  Eliminate it and rename print_usage() to just usage().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/conf.c b/conf.c
index 50383a39..f2a92574 100644
--- a/conf.c
+++ b/conf.c
@@ -704,11 +704,11 @@ static unsigned int conf_ip6(unsigned int ifi,
 }
 
 /**
- * print_usage() - Print usage, exit with given status code
+ * usage() - Print usage, exit with given status code
  * @name:	Executable name
  * @status:	Status code for exit()
  */
-static void print_usage(const char *name, int status)
+static void usage(const char *name, int status)
 {
 	if (strstr(name, "pasta")) {
 		info("Usage: %s [OPTION]... [COMMAND] [ARGS]...", name);
@@ -897,15 +897,6 @@ pasta_opts:
 	exit(status);
 }
 
-/**
- * usage() - Print usage and exit with failure
- * @name:	Executable name
- */
-static void usage(const char *name)
-{
-	print_usage(name, EXIT_FAILURE);
-}
-
 /**
  * conf_print() - Print fundamental configuration parameters
  * @c:		Execution context
@@ -1647,11 +1638,11 @@ void conf(struct ctx *c, int argc, char **argv)
 			break;
 		case 'h':
 			log_to_stdout = 1;
-			print_usage(argv[0], EXIT_SUCCESS);
+			usage(argv[0], EXIT_SUCCESS);
 			break;
 		case '?':
 		default:
-			usage(argv[0]);
+			usage(argv[0], EXIT_FAILURE);
 			break;
 		}
 	} while (name != -1);
-- 
@@ -704,11 +704,11 @@ static unsigned int conf_ip6(unsigned int ifi,
 }
 
 /**
- * print_usage() - Print usage, exit with given status code
+ * usage() - Print usage, exit with given status code
  * @name:	Executable name
  * @status:	Status code for exit()
  */
-static void print_usage(const char *name, int status)
+static void usage(const char *name, int status)
 {
 	if (strstr(name, "pasta")) {
 		info("Usage: %s [OPTION]... [COMMAND] [ARGS]...", name);
@@ -897,15 +897,6 @@ pasta_opts:
 	exit(status);
 }
 
-/**
- * usage() - Print usage and exit with failure
- * @name:	Executable name
- */
-static void usage(const char *name)
-{
-	print_usage(name, EXIT_FAILURE);
-}
-
 /**
  * conf_print() - Print fundamental configuration parameters
  * @c:		Execution context
@@ -1647,11 +1638,11 @@ void conf(struct ctx *c, int argc, char **argv)
 			break;
 		case 'h':
 			log_to_stdout = 1;
-			print_usage(argv[0], EXIT_SUCCESS);
+			usage(argv[0], EXIT_SUCCESS);
 			break;
 		case '?':
 		default:
-			usage(argv[0]);
+			usage(argv[0], EXIT_FAILURE);
 			break;
 		}
 	} while (name != -1);
-- 
2.45.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 2/3] conf: Don't print usage via the logging subsystem
  2024-05-29  9:04 [PATCH 0/3] conf, log: Fix regression in usage() printing David Gibson
  2024-05-29  9:04 ` [PATCH 1/3] conf: Remove unhelpful usage() wrapper David Gibson
@ 2024-05-29  9:04 ` David Gibson
  2024-06-04 22:40   ` Stefano Brivio
  2024-05-29  9:04 ` [PATCH 3/3] log: Remove log_to_stdout option David Gibson
  2 siblings, 1 reply; 6+ messages in thread
From: David Gibson @ 2024-05-29  9:04 UTC (permalink / raw)
  To: passt-dev, Stefano Brivio; +Cc: erik.sjolund, David Gibson

The message from usage() when given invalid options, or the -h / --help
option is currently printed by many calls to the info() function, also
used for runtime logging of informational messages.

That isn't useful: the usage message should always go to the terminal
(stdout or stderr), never syslog or a logfile.  It should never be
filtered by priority.  Really the only thing using the common logging
functions does is give more opportunities for something to go wrong.

Replace all the info() calls with direct fprintf() calls.  This does mean
manually adding "\n" to each message.  A little messy, but worth it for the
simplicity in other dimensions.

Link: https://bugs.passt.top/show_bug.cgi?id=90

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c | 318 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 159 insertions(+), 159 deletions(-)

diff --git a/conf.c b/conf.c
index f2a92574..31f5b197 100644
--- a/conf.c
+++ b/conf.c
@@ -706,193 +706,194 @@ static unsigned int conf_ip6(unsigned int ifi,
 /**
  * usage() - Print usage, exit with given status code
  * @name:	Executable name
+ * @f:		Stream to print usage info to
  * @status:	Status code for exit()
  */
-static void usage(const char *name, int status)
+static void usage(const char *name, FILE *f, int status)
 {
 	if (strstr(name, "pasta")) {
-		info("Usage: %s [OPTION]... [COMMAND] [ARGS]...", name);
-		info("       %s [OPTION]... PID", name);
-		info("       %s [OPTION]... --netns [PATH|NAME]", name);
-		info("");
-		info("Without PID or --netns, run the given command or a");
-		info("default shell in a new network and user namespace, and");
-		info("connect it via pasta.");
+		fprintf(f, "Usage: %s [OPTION]... [COMMAND] [ARGS]...\n", name);
+		fprintf(f, "       %s [OPTION]... PID\n", name);
+		fprintf(f, "       %s [OPTION]... --netns [PATH|NAME]\n", name);
+		fprintf(f, "\n");
+		fprintf(f, "Without PID or --netns, run the given command or a\n");
+		fprintf(f, "default shell in a new network and user namespace, and\n");
+		fprintf(f, "connect it via pasta.\n");
 	} else {
-		info("Usage: %s [OPTION]...", name);
+		fprintf(f, "Usage: %s [OPTION]...\n", name);
 	}
-	info("");
-
-
-	info(   "  -d, --debug		Be verbose");
-	info(   "      --trace		Be extra verbose, implies --debug");
-	info(   "  -q, --quiet		Don't print informational messages");
-	info(   "  -f, --foreground	Don't run in background");
-	info(   "    default: run in background if started from a TTY");
-	info(   "  -e, --stderr		Log to stderr too");
-	info(   "    default: log to system logger only if started from a TTY");
-	info(   "  -l, --log-file PATH	Log (only) to given file");
-	info(   "  --log-size BYTES	Maximum size of log file");
-	info(   "    default: 1 MiB");
-	info(   "  --runas UID|UID:GID 	Run as given UID, GID, which can be");
-	info(   "    numeric, or login and group names");
-	info(   "    default: drop to user \"nobody\"");
-	info(   "  -h, --help		Display this help message and exit");
-	info(   "  --version		Show version and exit");
+	fprintf(f, "\n");
+
+
+	fprintf(f, "  -d, --debug		Be verbose\n");
+	fprintf(f, "      --trace		Be extra verbose, implies --debug\n");
+	fprintf(f, "  -q, --quiet		Don't print informational messages\n");
+	fprintf(f, "  -f, --foreground	Don't run in background\n");
+	fprintf(f, "    default: run in background if started from a TTY\n");
+	fprintf(f, "  -e, --stderr		Log to stderr too\n");
+	fprintf(f, "    default: log to system logger only if started from a TTY\n");
+	fprintf(f, "  -l, --log-file PATH	Log (only) to given file\n");
+	fprintf(f, "  --log-size BYTES	Maximum size of log file\n");
+	fprintf(f, "    default: 1 MiB\n");
+	fprintf(f, "  --runas UID|UID:GID 	Run as given UID, GID, which can be\n");
+	fprintf(f, "    numeric, or login and group names\n");
+	fprintf(f, "    default: drop to user \"nobody\"\n");
+	fprintf(f, "  -h, --help		Display this help message and exit\n");
+	fprintf(f, "  --version		Show version and exit\n");
 
 	if (strstr(name, "pasta")) {
-		info(   "  -I, --ns-ifname NAME	namespace interface name");
-		info(   "    default: same interface name as external one");
+		fprintf(f, "  -I, --ns-ifname NAME	namespace interface name\n");
+		fprintf(f, "    default: same interface name as external one\n");
 	} else {
-		info(   "  -s, --socket PATH	UNIX domain socket path");
-		info(   "    default: probe free path starting from "
-		     UNIX_SOCK_PATH, 1);
+		fprintf(f, "  -s, --socket PATH	UNIX domain socket path\n");
+		fprintf(f, "    default: probe free path starting from "
+		     UNIX_SOCK_PATH "\n", 1);
 	}
 
-	info(   "  -F, --fd FD		Use FD as pre-opened connected socket");
-	info(   "  -p, --pcap FILE	Log tap-facing traffic to pcap file");
-	info(   "  -P, --pid FILE	Write own PID to the given file");
-	info(   "  -m, --mtu MTU	Assign MTU via DHCP/NDP");
-	info(   "    a zero value disables assignment");
-	info(   "    default: 65520: maximum 802.3 MTU minus 802.3 header");
-	info(   "                    length, rounded to 32 bits (IPv4 words)");
-	info(   "  -a, --address ADDR	Assign IPv4 or IPv6 address ADDR");
-	info(   "    can be specified zero to two times (for IPv4 and IPv6)");
-	info(   "    default: use addresses from interface with default route");
-	info(   "  -n, --netmask MASK	Assign IPv4 MASK, dot-decimal or bits");
-	info(   "    default: netmask from matching address on the host");
-	info(   "  -M, --mac-addr ADDR	Use source MAC address ADDR");
-	info(   "    default: MAC address from interface with default route");
-	info(   "  -g, --gateway ADDR	Pass IPv4 or IPv6 address as gateway");
-	info(   "    default: gateway from interface with default route");
-	info(   "  -i, --interface NAME	Interface for addresses and routes");
-	info(   "    default: from --outbound-if4 and --outbound-if6, if any");
-	info(   "             otherwise interface with first default route");
-	info(   "  -o, --outbound ADDR	Bind to address as outbound source");
-	info(   "    can be specified zero to two times (for IPv4 and IPv6)");
-	info(   "    default: use source address from routing tables");
-	info(   "  --outbound-if4 NAME	Bind to outbound interface for IPv4");
-	info(   "    default: use interface from default route");
-	info(   "  --outbound-if6 NAME	Bind to outbound interface for IPv6");
-	info(   "    default: use interface from default route");
-	info(   "  -D, --dns ADDR	Use IPv4 or IPv6 address as DNS");
-	info(   "    can be specified multiple times");
-	info(   "    a single, empty option disables DNS information");
+	fprintf(f, "  -F, --fd FD		Use FD as pre-opened connected socket\n");
+	fprintf(f, "  -p, --pcap FILE	Log tap-facing traffic to pcap file\n");
+	fprintf(f, "  -P, --pid FILE	Write own PID to the given file\n");
+	fprintf(f, "  -m, --mtu MTU	Assign MTU via DHCP/NDP\n");
+	fprintf(f, "    a zero value disables assignment\n");
+	fprintf(f, "    default: 65520: maximum 802.3 MTU minus 802.3 header\n");
+	fprintf(f, "                    length, rounded to 32 bits (IPv4 words)\n");
+	fprintf(f, "  -a, --address ADDR	Assign IPv4 or IPv6 address ADDR\n");
+	fprintf(f, "    can be specified zero to two times (for IPv4 and IPv6)\n");
+	fprintf(f, "    default: use addresses from interface with default route\n");
+	fprintf(f, "  -n, --netmask MASK	Assign IPv4 MASK, dot-decimal or bits\n");
+	fprintf(f, "    default: netmask from matching address on the host\n");
+	fprintf(f, "  -M, --mac-addr ADDR	Use source MAC address ADDR\n");
+	fprintf(f, "    default: MAC address from interface with default route\n");
+	fprintf(f, "  -g, --gateway ADDR	Pass IPv4 or IPv6 address as gateway\n");
+	fprintf(f, "    default: gateway from interface with default route\n");
+	fprintf(f, "  -i, --interface NAME	Interface for addresses and routes\n");
+	fprintf(f, "    default: from --outbound-if4 and --outbound-if6, if any\n");
+	fprintf(f, "             otherwise interface with first default route\n");
+	fprintf(f, "  -o, --outbound ADDR	Bind to address as outbound source\n");
+	fprintf(f, "    can be specified zero to two times (for IPv4 and IPv6)\n");
+	fprintf(f, "    default: use source address from routing tables\n");
+	fprintf(f, "  --outbound-if4 NAME	Bind to outbound interface for IPv4\n");
+	fprintf(f, "    default: use interface from default route\n");
+	fprintf(f, "  --outbound-if6 NAME	Bind to outbound interface for IPv6\n");
+	fprintf(f, "    default: use interface from default route\n");
+	fprintf(f, "  -D, --dns ADDR	Use IPv4 or IPv6 address as DNS\n");
+	fprintf(f, "    can be specified multiple times\n");
+	fprintf(f, "    a single, empty option disables DNS information\n");
 	if (strstr(name, "pasta"))
-		info(   "    default: don't use any addresses");
+		fprintf(f, "    default: don't use any addresses\n");
 	else
-		info(   "    default: use addresses from /etc/resolv.conf");
+		fprintf(f, "    default: use addresses from /etc/resolv.conf\n");
 
-	info(   "  -S, --search LIST	Space-separated list, search domains");
-	info(   "    a single, empty option disables the DNS search list");
+	fprintf(f, "  -S, --search LIST	Space-separated list, search domains\n");
+	fprintf(f, "    a single, empty option disables the DNS search list\n");
 	if (strstr(name, "pasta"))
-		info(   "    default: don't use any search list");
+		fprintf(f, "    default: don't use any search list\n");
 	else
-		info(   "    default: use search list from /etc/resolv.conf");
+		fprintf(f, "    default: use search list from /etc/resolv.conf\n");
 
 	if (strstr(name, "pasta"))
-		info("  --dhcp-dns	\tPass DNS list via DHCP/DHCPv6/NDP");
+		fprintf(f, "  --dhcp-dns	\tPass DNS list via DHCP/DHCPv6/NDP\n");
 	else
-		info("  --no-dhcp-dns	No DNS list in DHCP/DHCPv6/NDP");
+		fprintf(f, "  --no-dhcp-dns	No DNS list in DHCP/DHCPv6/NDP\n");
 
 	if (strstr(name, "pasta"))
-		info("  --dhcp-search	Pass list via DHCP/DHCPv6/NDP");
+		fprintf(f, "  --dhcp-search	Pass list via DHCP/DHCPv6/NDP\n");
 	else
-		info("  --no-dhcp-search	No list in DHCP/DHCPv6/NDP");
-
-	info(   "  --dns-forward ADDR	Forward DNS queries sent to ADDR");
-	info(   "    can be specified zero to two times (for IPv4 and IPv6)");
-	info(   "    default: don't forward DNS queries");
-
-	info(   "  --no-tcp		Disable TCP protocol handler");
-	info(   "  --no-udp		Disable UDP protocol handler");
-	info(   "  --no-icmp		Disable ICMP/ICMPv6 protocol handler");
-	info(   "  --no-dhcp		Disable DHCP server");
-	info(   "  --no-ndp		Disable NDP responses");
-	info(   "  --no-dhcpv6		Disable DHCPv6 server");
-	info(   "  --no-ra		Disable router advertisements");
-	info(   "  --no-map-gw		Don't map gateway address to host");
-	info(   "  -4, --ipv4-only	Enable IPv4 operation only");
-	info(   "  -6, --ipv6-only	Enable IPv6 operation only");
+		fprintf(f, "  --no-dhcp-search	No list in DHCP/DHCPv6/NDP\n");
+
+	fprintf(f, "  --dns-forward ADDR	Forward DNS queries sent to ADDR\n");
+	fprintf(f, "    can be specified zero to two times (for IPv4 and IPv6)\n");
+	fprintf(f, "    default: don't forward DNS queries\n");
+
+	fprintf(f, "  --no-tcp		Disable TCP protocol handler\n");
+	fprintf(f, "  --no-udp		Disable UDP protocol handler\n");
+	fprintf(f, "  --no-icmp		Disable ICMP/ICMPv6 protocol handler\n");
+	fprintf(f, "  --no-dhcp		Disable DHCP server\n");
+	fprintf(f, "  --no-ndp		Disable NDP responses\n");
+	fprintf(f, "  --no-dhcpv6		Disable DHCPv6 server\n");
+	fprintf(f, "  --no-ra		Disable router advertisements\n");
+	fprintf(f, "  --no-map-gw		Don't map gateway address to host\n");
+	fprintf(f, "  -4, --ipv4-only	Enable IPv4 operation only\n");
+	fprintf(f, "  -6, --ipv6-only	Enable IPv6 operation only\n");
 
 	if (strstr(name, "pasta"))
 		goto pasta_opts;
 
-	info(   "  -1, --one-off	Quit after handling one single client");
-	info(   "  -t, --tcp-ports SPEC	TCP port forwarding to guest");
-	info(   "    can be specified multiple times");
-	info(   "    SPEC can be:");
-	info(   "      'none': don't forward any ports");
-	info(   "      'all': forward all unbound, non-ephemeral ports");
-	info(   "      a comma-separated list, optionally ranged with '-'");
-	info(   "        and optional target ports after ':', with optional");
-	info(   "        address specification suffixed by '/' and optional");
-	info(   "        interface prefixed by '%%'. Ranges can be reduced by");
-	info(   "        excluding ports or ranges prefixed by '~'");
-	info(   "        Examples:");
-	info(   "        -t 22		Forward local port 22 to 22 on guest");
-	info(   "        -t 22:23	Forward local port 22 to 23 on guest");
-	info(   "        -t 22,25	Forward ports 22, 25 to ports 22, 25");
-	info(   "        -t 22-80  	Forward ports 22 to 80");
-	info(   "        -t 22-80:32-90	Forward ports 22 to 80 to");
-	info(   "			corresponding port numbers plus 10");
-	info(   "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to guest");
-	info(   "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25");
-	info(   "        -t ~25		Forward all ports except for 25");
-	info(   "    default: none");
-	info(   "  -u, --udp-ports SPEC	UDP port forwarding to guest");
-	info(   "    SPEC is as described for TCP above");
-	info(   "    default: none");
+	fprintf(f, "  -1, --one-off	Quit after handling one single client\n");
+	fprintf(f, "  -t, --tcp-ports SPEC	TCP port forwarding to guest\n");
+	fprintf(f, "    can be specified multiple times\n");
+	fprintf(f, "    SPEC can be:\n");
+	fprintf(f, "      'none': don't forward any ports\n");
+	fprintf(f, "      'all': forward all unbound, non-ephemeral ports\n");
+	fprintf(f, "      a comma-separated list, optionally ranged with '-'\n");
+	fprintf(f, "        and optional target ports after ':', with optional\n");
+	fprintf(f, "        address specification suffixed by '/' and optional\n");
+	fprintf(f, "        interface prefixed by '%%'. Ranges can be reduced by\n");
+	fprintf(f, "        excluding ports or ranges prefixed by '~'\n");
+	fprintf(f, "        Examples:\n");
+	fprintf(f, "        -t 22		Forward local port 22 to 22 on guest\n");
+	fprintf(f, "        -t 22:23	Forward local port 22 to 23 on guest\n");
+	fprintf(f, "        -t 22,25	Forward ports 22, 25 to ports 22, 25\n");
+	fprintf(f, "        -t 22-80  	Forward ports 22 to 80\n");
+	fprintf(f, "        -t 22-80:32-90	Forward ports 22 to 80 to\n");
+	fprintf(f, "			corresponding port numbers plus 10\n");
+	fprintf(f, "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to guest\n");
+	fprintf(f, "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25\n");
+	fprintf(f, "        -t ~25		Forward all ports except for 25\n");
+	fprintf(f, "    default: none\n");
+	fprintf(f, "  -u, --udp-ports SPEC	UDP port forwarding to guest\n");
+	fprintf(f, "    SPEC is as described for TCP above\n");
+	fprintf(f, "    default: none\n");
 
 	exit(status);
 
 pasta_opts:
 
-	info(   "  -t, --tcp-ports SPEC	TCP port forwarding to namespace");
-	info(   "    can be specified multiple times"); 
-	info(   "    SPEC can be:");
-	info(   "      'none': don't forward any ports");
-	info(   "      'auto': forward all ports currently bound in namespace");
-	info(   "      a comma-separated list, optionally ranged with '-'");
-	info(   "        and optional target ports after ':', with optional");
-	info(   "        address specification suffixed by '/' and optional");
-	info(   "        interface prefixed by '%%'. Examples:");
-	info(   "        -t 22	Forward local port 22 to port 22 in netns");
-	info(   "        -t 22:23	Forward local port 22 to port 23");
-	info(   "        -t 22,25	Forward ports 22, 25 to ports 22, 25");
-	info(   "        -t 22-80	Forward ports 22 to 80");
-	info(   "        -t 22-80:32-90	Forward ports 22 to 80 to");
-	info(   "			corresponding port numbers plus 10");
-	info(   "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to namespace");
-	info(   "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25");
-	info(   "        -t ~25		Forward all bound ports except for 25");
-	info(   "    default: auto");
-	info(   "    IPv6 bound ports are also forwarded for IPv4");
-	info(   "  -u, --udp-ports SPEC	UDP port forwarding to namespace");
-	info(   "    SPEC is as described for TCP above");
-	info(   "    default: auto");
-	info(   "    IPv6 bound ports are also forwarded for IPv4");
-	info(   "    unless specified, with '-t auto', UDP ports with numbers");
-	info(   "    corresponding to forwarded TCP port numbers are");
-	info(   "    forwarded too");
-	info(   "  -T, --tcp-ns SPEC	TCP port forwarding to init namespace");
-	info(   "    SPEC is as described above");
-	info(   "    default: auto");
-	info(   "  -U, --udp-ns SPEC	UDP port forwarding to init namespace");
-	info(   "    SPEC is as described above");
-	info(   "    default: auto");
-	info(   "  --userns NSPATH 	Target user namespace to join");
-	info(   "  --netns PATH|NAME	Target network namespace to join");
-	info(   "  --netns-only		Don't join existing user namespace");
-	info(   "    implied if PATH or NAME are given without --userns");
-	info(   "  --no-netns-quit	Don't quit if filesystem-bound target");
-	info(   "  			network namespace is deleted");
-	info(   "  --config-net		Configure tap interface in namespace");
-	info(   "  --no-copy-routes	DEPRECATED:");
-	info(   "			Don't copy all routes to namespace");
-	info(   "  --no-copy-addrs	DEPRECATED:");
-	info(   "			Don't copy all addresses to namespace");
-	info(   "  --ns-mac-addr ADDR	Set MAC address on tap interface");
+	fprintf(f, "  -t, --tcp-ports SPEC	TCP port forwarding to namespace\n");
+	fprintf(f, "    can be specified multiple times\n");
+	fprintf(f, "    SPEC can be:\n");
+	fprintf(f, "      'none': don't forward any ports\n");
+	fprintf(f, "      'auto': forward all ports currently bound in namespace\n");
+	fprintf(f, "      a comma-separated list, optionally ranged with '-'\n");
+	fprintf(f, "        and optional target ports after ':', with optional\n");
+	fprintf(f, "        address specification suffixed by '/' and optional\n");
+	fprintf(f, "        interface prefixed by '%%'. Examples:\n");
+	fprintf(f, "        -t 22	Forward local port 22 to port 22 in netns\n");
+	fprintf(f, "        -t 22:23	Forward local port 22 to port 23\n");
+	fprintf(f, "        -t 22,25	Forward ports 22, 25 to ports 22, 25\n");
+	fprintf(f, "        -t 22-80	Forward ports 22 to 80\n");
+	fprintf(f, "        -t 22-80:32-90	Forward ports 22 to 80 to\n");
+	fprintf(f, "			corresponding port numbers plus 10\n");
+	fprintf(f, "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to namespace\n");
+	fprintf(f, "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25\n");
+	fprintf(f, "        -t ~25		Forward all bound ports except for 25\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "    IPv6 bound ports are also forwarded for IPv4\n");
+	fprintf(f, "  -u, --udp-ports SPEC	UDP port forwarding to namespace\n");
+	fprintf(f, "    SPEC is as described for TCP above\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "    IPv6 bound ports are also forwarded for IPv4\n");
+	fprintf(f, "    unless specified, with '-t auto', UDP ports with numbers\n");
+	fprintf(f, "    corresponding to forwarded TCP port numbers are\n");
+	fprintf(f, "    forwarded too\n");
+	fprintf(f, "  -T, --tcp-ns SPEC	TCP port forwarding to init namespace\n");
+	fprintf(f, "    SPEC is as described above\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "  -U, --udp-ns SPEC	UDP port forwarding to init namespace\n");
+	fprintf(f, "    SPEC is as described above\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "  --userns NSPATH 	Target user namespace to join\n");
+	fprintf(f, "  --netns PATH|NAME	Target network namespace to join\n");
+	fprintf(f, "  --netns-only		Don't join existing user namespace\n");
+	fprintf(f, "    implied if PATH or NAME are given without --userns\n");
+	fprintf(f, "  --no-netns-quit	Don't quit if filesystem-bound target\n");
+	fprintf(f, "  			network namespace is deleted\n");
+	fprintf(f, "  --config-net		Configure tap interface in namespace\n");
+	fprintf(f, "  --no-copy-routes	DEPRECATED:\n");
+	fprintf(f, "			Don't copy all routes to namespace\n");
+	fprintf(f, "  --no-copy-addrs	DEPRECATED:\n");
+	fprintf(f, "			Don't copy all addresses to namespace\n");
+	fprintf(f, "  --ns-mac-addr ADDR	Set MAC address on tap interface\n");
 
 	exit(status);
 }
@@ -1637,12 +1638,11 @@ void conf(struct ctx *c, int argc, char **argv)
 			/* Handle these later, once addresses are configured */
 			break;
 		case 'h':
-			log_to_stdout = 1;
-			usage(argv[0], EXIT_SUCCESS);
+			usage(argv[0], stdout, EXIT_SUCCESS);
 			break;
 		case '?':
 		default:
-			usage(argv[0], EXIT_FAILURE);
+			usage(argv[0], stderr, EXIT_FAILURE);
 			break;
 		}
 	} while (name != -1);
-- 
@@ -706,193 +706,194 @@ static unsigned int conf_ip6(unsigned int ifi,
 /**
  * usage() - Print usage, exit with given status code
  * @name:	Executable name
+ * @f:		Stream to print usage info to
  * @status:	Status code for exit()
  */
-static void usage(const char *name, int status)
+static void usage(const char *name, FILE *f, int status)
 {
 	if (strstr(name, "pasta")) {
-		info("Usage: %s [OPTION]... [COMMAND] [ARGS]...", name);
-		info("       %s [OPTION]... PID", name);
-		info("       %s [OPTION]... --netns [PATH|NAME]", name);
-		info("");
-		info("Without PID or --netns, run the given command or a");
-		info("default shell in a new network and user namespace, and");
-		info("connect it via pasta.");
+		fprintf(f, "Usage: %s [OPTION]... [COMMAND] [ARGS]...\n", name);
+		fprintf(f, "       %s [OPTION]... PID\n", name);
+		fprintf(f, "       %s [OPTION]... --netns [PATH|NAME]\n", name);
+		fprintf(f, "\n");
+		fprintf(f, "Without PID or --netns, run the given command or a\n");
+		fprintf(f, "default shell in a new network and user namespace, and\n");
+		fprintf(f, "connect it via pasta.\n");
 	} else {
-		info("Usage: %s [OPTION]...", name);
+		fprintf(f, "Usage: %s [OPTION]...\n", name);
 	}
-	info("");
-
-
-	info(   "  -d, --debug		Be verbose");
-	info(   "      --trace		Be extra verbose, implies --debug");
-	info(   "  -q, --quiet		Don't print informational messages");
-	info(   "  -f, --foreground	Don't run in background");
-	info(   "    default: run in background if started from a TTY");
-	info(   "  -e, --stderr		Log to stderr too");
-	info(   "    default: log to system logger only if started from a TTY");
-	info(   "  -l, --log-file PATH	Log (only) to given file");
-	info(   "  --log-size BYTES	Maximum size of log file");
-	info(   "    default: 1 MiB");
-	info(   "  --runas UID|UID:GID 	Run as given UID, GID, which can be");
-	info(   "    numeric, or login and group names");
-	info(   "    default: drop to user \"nobody\"");
-	info(   "  -h, --help		Display this help message and exit");
-	info(   "  --version		Show version and exit");
+	fprintf(f, "\n");
+
+
+	fprintf(f, "  -d, --debug		Be verbose\n");
+	fprintf(f, "      --trace		Be extra verbose, implies --debug\n");
+	fprintf(f, "  -q, --quiet		Don't print informational messages\n");
+	fprintf(f, "  -f, --foreground	Don't run in background\n");
+	fprintf(f, "    default: run in background if started from a TTY\n");
+	fprintf(f, "  -e, --stderr		Log to stderr too\n");
+	fprintf(f, "    default: log to system logger only if started from a TTY\n");
+	fprintf(f, "  -l, --log-file PATH	Log (only) to given file\n");
+	fprintf(f, "  --log-size BYTES	Maximum size of log file\n");
+	fprintf(f, "    default: 1 MiB\n");
+	fprintf(f, "  --runas UID|UID:GID 	Run as given UID, GID, which can be\n");
+	fprintf(f, "    numeric, or login and group names\n");
+	fprintf(f, "    default: drop to user \"nobody\"\n");
+	fprintf(f, "  -h, --help		Display this help message and exit\n");
+	fprintf(f, "  --version		Show version and exit\n");
 
 	if (strstr(name, "pasta")) {
-		info(   "  -I, --ns-ifname NAME	namespace interface name");
-		info(   "    default: same interface name as external one");
+		fprintf(f, "  -I, --ns-ifname NAME	namespace interface name\n");
+		fprintf(f, "    default: same interface name as external one\n");
 	} else {
-		info(   "  -s, --socket PATH	UNIX domain socket path");
-		info(   "    default: probe free path starting from "
-		     UNIX_SOCK_PATH, 1);
+		fprintf(f, "  -s, --socket PATH	UNIX domain socket path\n");
+		fprintf(f, "    default: probe free path starting from "
+		     UNIX_SOCK_PATH "\n", 1);
 	}
 
-	info(   "  -F, --fd FD		Use FD as pre-opened connected socket");
-	info(   "  -p, --pcap FILE	Log tap-facing traffic to pcap file");
-	info(   "  -P, --pid FILE	Write own PID to the given file");
-	info(   "  -m, --mtu MTU	Assign MTU via DHCP/NDP");
-	info(   "    a zero value disables assignment");
-	info(   "    default: 65520: maximum 802.3 MTU minus 802.3 header");
-	info(   "                    length, rounded to 32 bits (IPv4 words)");
-	info(   "  -a, --address ADDR	Assign IPv4 or IPv6 address ADDR");
-	info(   "    can be specified zero to two times (for IPv4 and IPv6)");
-	info(   "    default: use addresses from interface with default route");
-	info(   "  -n, --netmask MASK	Assign IPv4 MASK, dot-decimal or bits");
-	info(   "    default: netmask from matching address on the host");
-	info(   "  -M, --mac-addr ADDR	Use source MAC address ADDR");
-	info(   "    default: MAC address from interface with default route");
-	info(   "  -g, --gateway ADDR	Pass IPv4 or IPv6 address as gateway");
-	info(   "    default: gateway from interface with default route");
-	info(   "  -i, --interface NAME	Interface for addresses and routes");
-	info(   "    default: from --outbound-if4 and --outbound-if6, if any");
-	info(   "             otherwise interface with first default route");
-	info(   "  -o, --outbound ADDR	Bind to address as outbound source");
-	info(   "    can be specified zero to two times (for IPv4 and IPv6)");
-	info(   "    default: use source address from routing tables");
-	info(   "  --outbound-if4 NAME	Bind to outbound interface for IPv4");
-	info(   "    default: use interface from default route");
-	info(   "  --outbound-if6 NAME	Bind to outbound interface for IPv6");
-	info(   "    default: use interface from default route");
-	info(   "  -D, --dns ADDR	Use IPv4 or IPv6 address as DNS");
-	info(   "    can be specified multiple times");
-	info(   "    a single, empty option disables DNS information");
+	fprintf(f, "  -F, --fd FD		Use FD as pre-opened connected socket\n");
+	fprintf(f, "  -p, --pcap FILE	Log tap-facing traffic to pcap file\n");
+	fprintf(f, "  -P, --pid FILE	Write own PID to the given file\n");
+	fprintf(f, "  -m, --mtu MTU	Assign MTU via DHCP/NDP\n");
+	fprintf(f, "    a zero value disables assignment\n");
+	fprintf(f, "    default: 65520: maximum 802.3 MTU minus 802.3 header\n");
+	fprintf(f, "                    length, rounded to 32 bits (IPv4 words)\n");
+	fprintf(f, "  -a, --address ADDR	Assign IPv4 or IPv6 address ADDR\n");
+	fprintf(f, "    can be specified zero to two times (for IPv4 and IPv6)\n");
+	fprintf(f, "    default: use addresses from interface with default route\n");
+	fprintf(f, "  -n, --netmask MASK	Assign IPv4 MASK, dot-decimal or bits\n");
+	fprintf(f, "    default: netmask from matching address on the host\n");
+	fprintf(f, "  -M, --mac-addr ADDR	Use source MAC address ADDR\n");
+	fprintf(f, "    default: MAC address from interface with default route\n");
+	fprintf(f, "  -g, --gateway ADDR	Pass IPv4 or IPv6 address as gateway\n");
+	fprintf(f, "    default: gateway from interface with default route\n");
+	fprintf(f, "  -i, --interface NAME	Interface for addresses and routes\n");
+	fprintf(f, "    default: from --outbound-if4 and --outbound-if6, if any\n");
+	fprintf(f, "             otherwise interface with first default route\n");
+	fprintf(f, "  -o, --outbound ADDR	Bind to address as outbound source\n");
+	fprintf(f, "    can be specified zero to two times (for IPv4 and IPv6)\n");
+	fprintf(f, "    default: use source address from routing tables\n");
+	fprintf(f, "  --outbound-if4 NAME	Bind to outbound interface for IPv4\n");
+	fprintf(f, "    default: use interface from default route\n");
+	fprintf(f, "  --outbound-if6 NAME	Bind to outbound interface for IPv6\n");
+	fprintf(f, "    default: use interface from default route\n");
+	fprintf(f, "  -D, --dns ADDR	Use IPv4 or IPv6 address as DNS\n");
+	fprintf(f, "    can be specified multiple times\n");
+	fprintf(f, "    a single, empty option disables DNS information\n");
 	if (strstr(name, "pasta"))
-		info(   "    default: don't use any addresses");
+		fprintf(f, "    default: don't use any addresses\n");
 	else
-		info(   "    default: use addresses from /etc/resolv.conf");
+		fprintf(f, "    default: use addresses from /etc/resolv.conf\n");
 
-	info(   "  -S, --search LIST	Space-separated list, search domains");
-	info(   "    a single, empty option disables the DNS search list");
+	fprintf(f, "  -S, --search LIST	Space-separated list, search domains\n");
+	fprintf(f, "    a single, empty option disables the DNS search list\n");
 	if (strstr(name, "pasta"))
-		info(   "    default: don't use any search list");
+		fprintf(f, "    default: don't use any search list\n");
 	else
-		info(   "    default: use search list from /etc/resolv.conf");
+		fprintf(f, "    default: use search list from /etc/resolv.conf\n");
 
 	if (strstr(name, "pasta"))
-		info("  --dhcp-dns	\tPass DNS list via DHCP/DHCPv6/NDP");
+		fprintf(f, "  --dhcp-dns	\tPass DNS list via DHCP/DHCPv6/NDP\n");
 	else
-		info("  --no-dhcp-dns	No DNS list in DHCP/DHCPv6/NDP");
+		fprintf(f, "  --no-dhcp-dns	No DNS list in DHCP/DHCPv6/NDP\n");
 
 	if (strstr(name, "pasta"))
-		info("  --dhcp-search	Pass list via DHCP/DHCPv6/NDP");
+		fprintf(f, "  --dhcp-search	Pass list via DHCP/DHCPv6/NDP\n");
 	else
-		info("  --no-dhcp-search	No list in DHCP/DHCPv6/NDP");
-
-	info(   "  --dns-forward ADDR	Forward DNS queries sent to ADDR");
-	info(   "    can be specified zero to two times (for IPv4 and IPv6)");
-	info(   "    default: don't forward DNS queries");
-
-	info(   "  --no-tcp		Disable TCP protocol handler");
-	info(   "  --no-udp		Disable UDP protocol handler");
-	info(   "  --no-icmp		Disable ICMP/ICMPv6 protocol handler");
-	info(   "  --no-dhcp		Disable DHCP server");
-	info(   "  --no-ndp		Disable NDP responses");
-	info(   "  --no-dhcpv6		Disable DHCPv6 server");
-	info(   "  --no-ra		Disable router advertisements");
-	info(   "  --no-map-gw		Don't map gateway address to host");
-	info(   "  -4, --ipv4-only	Enable IPv4 operation only");
-	info(   "  -6, --ipv6-only	Enable IPv6 operation only");
+		fprintf(f, "  --no-dhcp-search	No list in DHCP/DHCPv6/NDP\n");
+
+	fprintf(f, "  --dns-forward ADDR	Forward DNS queries sent to ADDR\n");
+	fprintf(f, "    can be specified zero to two times (for IPv4 and IPv6)\n");
+	fprintf(f, "    default: don't forward DNS queries\n");
+
+	fprintf(f, "  --no-tcp		Disable TCP protocol handler\n");
+	fprintf(f, "  --no-udp		Disable UDP protocol handler\n");
+	fprintf(f, "  --no-icmp		Disable ICMP/ICMPv6 protocol handler\n");
+	fprintf(f, "  --no-dhcp		Disable DHCP server\n");
+	fprintf(f, "  --no-ndp		Disable NDP responses\n");
+	fprintf(f, "  --no-dhcpv6		Disable DHCPv6 server\n");
+	fprintf(f, "  --no-ra		Disable router advertisements\n");
+	fprintf(f, "  --no-map-gw		Don't map gateway address to host\n");
+	fprintf(f, "  -4, --ipv4-only	Enable IPv4 operation only\n");
+	fprintf(f, "  -6, --ipv6-only	Enable IPv6 operation only\n");
 
 	if (strstr(name, "pasta"))
 		goto pasta_opts;
 
-	info(   "  -1, --one-off	Quit after handling one single client");
-	info(   "  -t, --tcp-ports SPEC	TCP port forwarding to guest");
-	info(   "    can be specified multiple times");
-	info(   "    SPEC can be:");
-	info(   "      'none': don't forward any ports");
-	info(   "      'all': forward all unbound, non-ephemeral ports");
-	info(   "      a comma-separated list, optionally ranged with '-'");
-	info(   "        and optional target ports after ':', with optional");
-	info(   "        address specification suffixed by '/' and optional");
-	info(   "        interface prefixed by '%%'. Ranges can be reduced by");
-	info(   "        excluding ports or ranges prefixed by '~'");
-	info(   "        Examples:");
-	info(   "        -t 22		Forward local port 22 to 22 on guest");
-	info(   "        -t 22:23	Forward local port 22 to 23 on guest");
-	info(   "        -t 22,25	Forward ports 22, 25 to ports 22, 25");
-	info(   "        -t 22-80  	Forward ports 22 to 80");
-	info(   "        -t 22-80:32-90	Forward ports 22 to 80 to");
-	info(   "			corresponding port numbers plus 10");
-	info(   "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to guest");
-	info(   "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25");
-	info(   "        -t ~25		Forward all ports except for 25");
-	info(   "    default: none");
-	info(   "  -u, --udp-ports SPEC	UDP port forwarding to guest");
-	info(   "    SPEC is as described for TCP above");
-	info(   "    default: none");
+	fprintf(f, "  -1, --one-off	Quit after handling one single client\n");
+	fprintf(f, "  -t, --tcp-ports SPEC	TCP port forwarding to guest\n");
+	fprintf(f, "    can be specified multiple times\n");
+	fprintf(f, "    SPEC can be:\n");
+	fprintf(f, "      'none': don't forward any ports\n");
+	fprintf(f, "      'all': forward all unbound, non-ephemeral ports\n");
+	fprintf(f, "      a comma-separated list, optionally ranged with '-'\n");
+	fprintf(f, "        and optional target ports after ':', with optional\n");
+	fprintf(f, "        address specification suffixed by '/' and optional\n");
+	fprintf(f, "        interface prefixed by '%%'. Ranges can be reduced by\n");
+	fprintf(f, "        excluding ports or ranges prefixed by '~'\n");
+	fprintf(f, "        Examples:\n");
+	fprintf(f, "        -t 22		Forward local port 22 to 22 on guest\n");
+	fprintf(f, "        -t 22:23	Forward local port 22 to 23 on guest\n");
+	fprintf(f, "        -t 22,25	Forward ports 22, 25 to ports 22, 25\n");
+	fprintf(f, "        -t 22-80  	Forward ports 22 to 80\n");
+	fprintf(f, "        -t 22-80:32-90	Forward ports 22 to 80 to\n");
+	fprintf(f, "			corresponding port numbers plus 10\n");
+	fprintf(f, "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to guest\n");
+	fprintf(f, "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25\n");
+	fprintf(f, "        -t ~25		Forward all ports except for 25\n");
+	fprintf(f, "    default: none\n");
+	fprintf(f, "  -u, --udp-ports SPEC	UDP port forwarding to guest\n");
+	fprintf(f, "    SPEC is as described for TCP above\n");
+	fprintf(f, "    default: none\n");
 
 	exit(status);
 
 pasta_opts:
 
-	info(   "  -t, --tcp-ports SPEC	TCP port forwarding to namespace");
-	info(   "    can be specified multiple times"); 
-	info(   "    SPEC can be:");
-	info(   "      'none': don't forward any ports");
-	info(   "      'auto': forward all ports currently bound in namespace");
-	info(   "      a comma-separated list, optionally ranged with '-'");
-	info(   "        and optional target ports after ':', with optional");
-	info(   "        address specification suffixed by '/' and optional");
-	info(   "        interface prefixed by '%%'. Examples:");
-	info(   "        -t 22	Forward local port 22 to port 22 in netns");
-	info(   "        -t 22:23	Forward local port 22 to port 23");
-	info(   "        -t 22,25	Forward ports 22, 25 to ports 22, 25");
-	info(   "        -t 22-80	Forward ports 22 to 80");
-	info(   "        -t 22-80:32-90	Forward ports 22 to 80 to");
-	info(   "			corresponding port numbers plus 10");
-	info(   "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to namespace");
-	info(   "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25");
-	info(   "        -t ~25		Forward all bound ports except for 25");
-	info(   "    default: auto");
-	info(   "    IPv6 bound ports are also forwarded for IPv4");
-	info(   "  -u, --udp-ports SPEC	UDP port forwarding to namespace");
-	info(   "    SPEC is as described for TCP above");
-	info(   "    default: auto");
-	info(   "    IPv6 bound ports are also forwarded for IPv4");
-	info(   "    unless specified, with '-t auto', UDP ports with numbers");
-	info(   "    corresponding to forwarded TCP port numbers are");
-	info(   "    forwarded too");
-	info(   "  -T, --tcp-ns SPEC	TCP port forwarding to init namespace");
-	info(   "    SPEC is as described above");
-	info(   "    default: auto");
-	info(   "  -U, --udp-ns SPEC	UDP port forwarding to init namespace");
-	info(   "    SPEC is as described above");
-	info(   "    default: auto");
-	info(   "  --userns NSPATH 	Target user namespace to join");
-	info(   "  --netns PATH|NAME	Target network namespace to join");
-	info(   "  --netns-only		Don't join existing user namespace");
-	info(   "    implied if PATH or NAME are given without --userns");
-	info(   "  --no-netns-quit	Don't quit if filesystem-bound target");
-	info(   "  			network namespace is deleted");
-	info(   "  --config-net		Configure tap interface in namespace");
-	info(   "  --no-copy-routes	DEPRECATED:");
-	info(   "			Don't copy all routes to namespace");
-	info(   "  --no-copy-addrs	DEPRECATED:");
-	info(   "			Don't copy all addresses to namespace");
-	info(   "  --ns-mac-addr ADDR	Set MAC address on tap interface");
+	fprintf(f, "  -t, --tcp-ports SPEC	TCP port forwarding to namespace\n");
+	fprintf(f, "    can be specified multiple times\n");
+	fprintf(f, "    SPEC can be:\n");
+	fprintf(f, "      'none': don't forward any ports\n");
+	fprintf(f, "      'auto': forward all ports currently bound in namespace\n");
+	fprintf(f, "      a comma-separated list, optionally ranged with '-'\n");
+	fprintf(f, "        and optional target ports after ':', with optional\n");
+	fprintf(f, "        address specification suffixed by '/' and optional\n");
+	fprintf(f, "        interface prefixed by '%%'. Examples:\n");
+	fprintf(f, "        -t 22	Forward local port 22 to port 22 in netns\n");
+	fprintf(f, "        -t 22:23	Forward local port 22 to port 23\n");
+	fprintf(f, "        -t 22,25	Forward ports 22, 25 to ports 22, 25\n");
+	fprintf(f, "        -t 22-80	Forward ports 22 to 80\n");
+	fprintf(f, "        -t 22-80:32-90	Forward ports 22 to 80 to\n");
+	fprintf(f, "			corresponding port numbers plus 10\n");
+	fprintf(f, "        -t 192.0.2.1/5	Bind port 5 of 192.0.2.1 to namespace\n");
+	fprintf(f, "        -t 5-25,~10-20	Forward ports 5 to 9, and 21 to 25\n");
+	fprintf(f, "        -t ~25		Forward all bound ports except for 25\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "    IPv6 bound ports are also forwarded for IPv4\n");
+	fprintf(f, "  -u, --udp-ports SPEC	UDP port forwarding to namespace\n");
+	fprintf(f, "    SPEC is as described for TCP above\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "    IPv6 bound ports are also forwarded for IPv4\n");
+	fprintf(f, "    unless specified, with '-t auto', UDP ports with numbers\n");
+	fprintf(f, "    corresponding to forwarded TCP port numbers are\n");
+	fprintf(f, "    forwarded too\n");
+	fprintf(f, "  -T, --tcp-ns SPEC	TCP port forwarding to init namespace\n");
+	fprintf(f, "    SPEC is as described above\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "  -U, --udp-ns SPEC	UDP port forwarding to init namespace\n");
+	fprintf(f, "    SPEC is as described above\n");
+	fprintf(f, "    default: auto\n");
+	fprintf(f, "  --userns NSPATH 	Target user namespace to join\n");
+	fprintf(f, "  --netns PATH|NAME	Target network namespace to join\n");
+	fprintf(f, "  --netns-only		Don't join existing user namespace\n");
+	fprintf(f, "    implied if PATH or NAME are given without --userns\n");
+	fprintf(f, "  --no-netns-quit	Don't quit if filesystem-bound target\n");
+	fprintf(f, "  			network namespace is deleted\n");
+	fprintf(f, "  --config-net		Configure tap interface in namespace\n");
+	fprintf(f, "  --no-copy-routes	DEPRECATED:\n");
+	fprintf(f, "			Don't copy all routes to namespace\n");
+	fprintf(f, "  --no-copy-addrs	DEPRECATED:\n");
+	fprintf(f, "			Don't copy all addresses to namespace\n");
+	fprintf(f, "  --ns-mac-addr ADDR	Set MAC address on tap interface\n");
 
 	exit(status);
 }
@@ -1637,12 +1638,11 @@ void conf(struct ctx *c, int argc, char **argv)
 			/* Handle these later, once addresses are configured */
 			break;
 		case 'h':
-			log_to_stdout = 1;
-			usage(argv[0], EXIT_SUCCESS);
+			usage(argv[0], stdout, EXIT_SUCCESS);
 			break;
 		case '?':
 		default:
-			usage(argv[0], EXIT_FAILURE);
+			usage(argv[0], stderr, EXIT_FAILURE);
 			break;
 		}
 	} while (name != -1);
-- 
2.45.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/3] conf: Don't print usage via the logging subsystem
  2024-05-29  9:04 ` [PATCH 2/3] conf: Don't print usage via the logging subsystem David Gibson
@ 2024-06-04 22:40   ` Stefano Brivio
  2024-06-04 23:51     ` David Gibson
  0 siblings, 1 reply; 6+ messages in thread
From: Stefano Brivio @ 2024-06-04 22:40 UTC (permalink / raw)
  To: David Gibson; +Cc: passt-dev, erik.sjolund

On Wed, 29 May 2024 19:04:04 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> The message from usage() when given invalid options, or the -h / --help
> option is currently printed by many calls to the info() function, also
> used for runtime logging of informational messages.
> 
> That isn't useful: the usage message should always go to the terminal
> (stdout or stderr), never syslog or a logfile.  It should never be
> filtered by priority.  Really the only thing using the common logging
> functions does is give more opportunities for something to go wrong.
> 
> Replace all the info() calls with direct fprintf() calls.  This does mean
> manually adding "\n" to each message.  A little messy, but worth it for the
> simplicity in other dimensions.

Yes, definitely less messy than the existing implementation, I just
wonder:

> Link: https://bugs.passt.top/show_bug.cgi?id=90
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  conf.c | 318 ++++++++++++++++++++++++++++-----------------------------
>  1 file changed, 159 insertions(+), 159 deletions(-)
> 
> diff --git a/conf.c b/conf.c
> index f2a92574..31f5b197 100644
> --- a/conf.c
> +++ b/conf.c
> @@ -706,193 +706,194 @@ static unsigned int conf_ip6(unsigned int ifi,
>  /**
>   * usage() - Print usage, exit with given status code
>   * @name:	Executable name
> + * @f:		Stream to print usage info to
>   * @status:	Status code for exit()
>   */
> -static void usage(const char *name, int status)
> +static void usage(const char *name, FILE *f, int status)
>  {
>  	if (strstr(name, "pasta")) {
> -		info("Usage: %s [OPTION]... [COMMAND] [ARGS]...", name);
> -		info("       %s [OPTION]... PID", name);
> -		info("       %s [OPTION]... --netns [PATH|NAME]", name);
> -		info("");
> -		info("Without PID or --netns, run the given command or a");
> -		info("default shell in a new network and user namespace, and");
> -		info("connect it via pasta.");
> +		fprintf(f, "Usage: %s [OPTION]... [COMMAND] [ARGS]...\n", name);
> +		fprintf(f, "       %s [OPTION]... PID\n", name);
> +		fprintf(f, "       %s [OPTION]... --netns [PATH|NAME]\n", name);
> +		fprintf(f, "\n");
> +		fprintf(f, "Without PID or --netns, run the given command or a\n");
> +		fprintf(f, "default shell in a new network and user namespace, and\n");
> +		fprintf(f, "connect it via pasta.\n");

I haven't checked how it looks like in the end, but in most of this
function, we use fprintf() without arguments after the format, and we
need explicit newlines anyway, so, what if we concatenate the whole
output, say:

		fprintf(f,
			"Without PID or --netns, run the given command or a\n"
			"default shell in a new network and user namespace, and\n"
			"connect it via pasta.\n"
			);

?

I used separate info() calls (or whatever they were) in the past
just because of the convenient newlines.

-- 
Stefano


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/3] conf: Don't print usage via the logging subsystem
  2024-06-04 22:40   ` Stefano Brivio
@ 2024-06-04 23:51     ` David Gibson
  0 siblings, 0 replies; 6+ messages in thread
From: David Gibson @ 2024-06-04 23:51 UTC (permalink / raw)
  To: Stefano Brivio; +Cc: passt-dev, erik.sjolund

[-- Attachment #1: Type: text/plain, Size: 3369 bytes --]

On Wed, Jun 05, 2024 at 12:40:41AM +0200, Stefano Brivio wrote:
> On Wed, 29 May 2024 19:04:04 +1000
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > The message from usage() when given invalid options, or the -h / --help
> > option is currently printed by many calls to the info() function, also
> > used for runtime logging of informational messages.
> > 
> > That isn't useful: the usage message should always go to the terminal
> > (stdout or stderr), never syslog or a logfile.  It should never be
> > filtered by priority.  Really the only thing using the common logging
> > functions does is give more opportunities for something to go wrong.
> > 
> > Replace all the info() calls with direct fprintf() calls.  This does mean
> > manually adding "\n" to each message.  A little messy, but worth it for the
> > simplicity in other dimensions.
> 
> Yes, definitely less messy than the existing implementation, I just
> wonder:
> 
> > Link: https://bugs.passt.top/show_bug.cgi?id=90
> > 
> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> > ---
> >  conf.c | 318 ++++++++++++++++++++++++++++-----------------------------
> >  1 file changed, 159 insertions(+), 159 deletions(-)
> > 
> > diff --git a/conf.c b/conf.c
> > index f2a92574..31f5b197 100644
> > --- a/conf.c
> > +++ b/conf.c
> > @@ -706,193 +706,194 @@ static unsigned int conf_ip6(unsigned int ifi,
> >  /**
> >   * usage() - Print usage, exit with given status code
> >   * @name:	Executable name
> > + * @f:		Stream to print usage info to
> >   * @status:	Status code for exit()
> >   */
> > -static void usage(const char *name, int status)
> > +static void usage(const char *name, FILE *f, int status)
> >  {
> >  	if (strstr(name, "pasta")) {
> > -		info("Usage: %s [OPTION]... [COMMAND] [ARGS]...", name);
> > -		info("       %s [OPTION]... PID", name);
> > -		info("       %s [OPTION]... --netns [PATH|NAME]", name);
> > -		info("");
> > -		info("Without PID or --netns, run the given command or a");
> > -		info("default shell in a new network and user namespace, and");
> > -		info("connect it via pasta.");
> > +		fprintf(f, "Usage: %s [OPTION]... [COMMAND] [ARGS]...\n", name);
> > +		fprintf(f, "       %s [OPTION]... PID\n", name);
> > +		fprintf(f, "       %s [OPTION]... --netns [PATH|NAME]\n", name);
> > +		fprintf(f, "\n");
> > +		fprintf(f, "Without PID or --netns, run the given command or a\n");
> > +		fprintf(f, "default shell in a new network and user namespace, and\n");
> > +		fprintf(f, "connect it via pasta.\n");
> 
> I haven't checked how it looks like in the end, but in most of this
> function, we use fprintf() without arguments after the format, and we
> need explicit newlines anyway, so, what if we concatenate the whole
> output, say:
> 
> 		fprintf(f,
> 			"Without PID or --netns, run the given command or a\n"
> 			"default shell in a new network and user namespace, and\n"
> 			"connect it via pasta.\n"
> 			);
> 
> ?

Fair point, I've made that change.

> I used separate info() calls (or whatever they were) in the past
> just because of the convenient newlines.
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 3/3] log: Remove log_to_stdout option
  2024-05-29  9:04 [PATCH 0/3] conf, log: Fix regression in usage() printing David Gibson
  2024-05-29  9:04 ` [PATCH 1/3] conf: Remove unhelpful usage() wrapper David Gibson
  2024-05-29  9:04 ` [PATCH 2/3] conf: Don't print usage via the logging subsystem David Gibson
@ 2024-05-29  9:04 ` David Gibson
  2 siblings, 0 replies; 6+ messages in thread
From: David Gibson @ 2024-05-29  9:04 UTC (permalink / raw)
  To: passt-dev, Stefano Brivio; +Cc: erik.sjolund, David Gibson

Now that we've simplified how usage() works, nothing ever sets the
log_to_stdout flag. Eliminate it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 log.c | 8 +++-----
 log.h | 1 -
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/log.c b/log.c
index e3630c35..aaf2beb5 100644
--- a/log.c
+++ b/log.c
@@ -46,18 +46,16 @@ static char	log_header[BUFSIZ];	/* File header, written back on cuts */
 
 static time_t	log_start;		/* Start timestamp */
 int		log_trace;		/* --trace mode enabled */
-int		log_to_stdout;		/* Print to stdout instead of stderr */
 
 void vlogmsg(int pri, const char *format, va_list ap)
 {
 	bool debug_print = (log_mask & LOG_MASK(LOG_DEBUG)) && log_file == -1;
 	bool early_print = LOG_PRI(log_mask) == LOG_EARLY;
-	FILE *out = log_to_stdout ? stdout : stderr;
 	struct timespec tp;
 
 	if (debug_print) {
 		clock_gettime(CLOCK_REALTIME, &tp);
-		fprintf(out, "%lli.%04lli: ",
+		fprintf(stderr, "%lli.%04lli: ",
 			(long long int)tp.tv_sec - log_start,
 			(long long int)tp.tv_nsec / (100L * 1000));
 	}
@@ -75,9 +73,9 @@ void vlogmsg(int pri, const char *format, va_list ap)
 	}
 
 	if (debug_print || (early_print && !(log_opt & LOG_PERROR))) {
-		(void)vfprintf(out, format, ap);
+		(void)vfprintf(stderr, format, ap);
 		if (format[strlen(format)] != '\n')
-			fprintf(out, "\n");
+			fprintf(stderr, "\n");
 	}
 }
 
diff --git a/log.h b/log.h
index 9c38182f..e0aab5a9 100644
--- a/log.h
+++ b/log.h
@@ -28,7 +28,6 @@ void logmsg(int pri, const char *format, ...)
 	} while (0)
 
 extern int log_trace;
-extern int log_to_stdout;
 void trace_init(int enable);
 #define trace(...)							\
 	do {								\
-- 
@@ -28,7 +28,6 @@ void logmsg(int pri, const char *format, ...)
 	} while (0)
 
 extern int log_trace;
-extern int log_to_stdout;
 void trace_init(int enable);
 #define trace(...)							\
 	do {								\
-- 
2.45.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2024-06-05  0:00 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-05-29  9:04 [PATCH 0/3] conf, log: Fix regression in usage() printing David Gibson
2024-05-29  9:04 ` [PATCH 1/3] conf: Remove unhelpful usage() wrapper David Gibson
2024-05-29  9:04 ` [PATCH 2/3] conf: Don't print usage via the logging subsystem David Gibson
2024-06-04 22:40   ` Stefano Brivio
2024-06-04 23:51     ` David Gibson
2024-05-29  9:04 ` [PATCH 3/3] log: Remove log_to_stdout option David Gibson

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