log: Drop newlines in the middle of the perror()-like messages

Calling vlogmsg() twice from logmsg_perror() results in this beauty:

  $ ./pasta -i foo
  Invalid interface name foo
  : No such device

because the first part of the message, corresponding to the first
call, doesn't end with a newline, and vlogmsg() adds it.

Given that we can't easily append an argument (error description) to
a variadic list, add a 'newline' parameter to all the functions that
currently add a newline if missing, and disable that on the first call
to vlogmsg() from logmsg_perror(). Not very pretty but I can't think
of any solution that's less messy than this.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Stefano Brivio 2024-07-24 16:36:17 +02:00
parent 13295583f8
commit 1cd773081f
3 changed files with 32 additions and 22 deletions

2
flow.c
View file

@ -279,7 +279,7 @@ void flow_log_(const struct flow_common *f, int pri, const char *fmt, ...)
else else
type_or_state = FLOW_TYPE(f); type_or_state = FLOW_TYPE(f);
logmsg(pri, "Flow %u (%s): %s", flow_idx(f), type_or_state, msg); logmsg(true, pri, "Flow %u (%s): %s", flow_idx(f), type_or_state, msg);
} }
/** /**

34
log.c
View file

@ -46,7 +46,14 @@ int log_trace; /* --trace mode enabled */
bool log_conf_parsed; /* Logging options already parsed */ bool log_conf_parsed; /* Logging options already parsed */
bool log_runtime; /* Daemonised, or ready in foreground */ bool log_runtime; /* Daemonised, or ready in foreground */
void vlogmsg(int pri, const char *format, va_list ap) /**
* vlogmsg() - Print or send messages to log or output files as configured
* @newline: Append newline at the end of the message, if missing
* @pri: Facility and level map, same as priority for vsyslog()
* @format: Message
* @ap: Variable argument list
*/
void vlogmsg(bool newline, int pri, const char *format, va_list ap)
{ {
bool debug_print = (log_mask & LOG_MASK(LOG_DEBUG)) && log_file == -1; bool debug_print = (log_mask & LOG_MASK(LOG_DEBUG)) && log_file == -1;
struct timespec tp; struct timespec tp;
@ -63,9 +70,9 @@ void vlogmsg(int pri, const char *format, va_list ap)
va_copy(ap2, ap); /* Don't clobber ap, we need it again */ va_copy(ap2, ap); /* Don't clobber ap, we need it again */
if (log_file != -1) if (log_file != -1)
logfile_write(pri, format, ap2); logfile_write(newline, pri, format, ap2);
else if (!(log_mask & LOG_MASK(LOG_DEBUG))) else if (!(log_mask & LOG_MASK(LOG_DEBUG)))
passt_vsyslog(pri, format, ap2); passt_vsyslog(newline, pri, format, ap2);
va_end(ap2); va_end(ap2);
} }
@ -73,22 +80,23 @@ void vlogmsg(int pri, const char *format, va_list ap)
if (debug_print || !log_conf_parsed || if (debug_print || !log_conf_parsed ||
(!log_runtime && (log_mask & LOG_MASK(LOG_PRI(pri))))) { (!log_runtime && (log_mask & LOG_MASK(LOG_PRI(pri))))) {
(void)vfprintf(stderr, format, ap); (void)vfprintf(stderr, format, ap);
if (format[strlen(format)] != '\n') if (newline && format[strlen(format)] != '\n')
fprintf(stderr, "\n"); fprintf(stderr, "\n");
} }
} }
/** /**
* logmsg() - vlogmsg() wrapper for variable argument lists * logmsg() - vlogmsg() wrapper for variable argument lists
* @newline: Append newline at the end of the message, if missing
* @pri: Facility and level map, same as priority for vsyslog() * @pri: Facility and level map, same as priority for vsyslog()
* @format: Message * @format: Message
*/ */
void logmsg(int pri, const char *format, ...) void logmsg(bool newline, int pri, const char *format, ...)
{ {
va_list ap; va_list ap;
va_start(ap, format); va_start(ap, format);
vlogmsg(pri, format, ap); vlogmsg(newline, pri, format, ap);
va_end(ap); va_end(ap);
} }
@ -103,10 +111,10 @@ void logmsg_perror(int pri, const char *format, ...)
va_list ap; va_list ap;
va_start(ap, format); va_start(ap, format);
vlogmsg(pri, format, ap); vlogmsg(false, pri, format, ap);
va_end(ap); va_end(ap);
logmsg(pri, ": %s", strerror(errno_copy)); logmsg(true, pri, ": %s", strerror(errno_copy));
} }
/* Prefixes for log file messages, indexed by priority */ /* Prefixes for log file messages, indexed by priority */
@ -174,11 +182,12 @@ void __setlogmask(int mask)
/** /**
* passt_vsyslog() - vsyslog() implementation not using heap memory * passt_vsyslog() - vsyslog() implementation not using heap memory
* @newline: Append newline at the end of the message, if missing
* @pri: Facility and level map, same as priority for vsyslog() * @pri: Facility and level map, same as priority for vsyslog()
* @format: Same as vsyslog() format * @format: Same as vsyslog() format
* @ap: Same as vsyslog() ap * @ap: Same as vsyslog() ap
*/ */
void passt_vsyslog(int pri, const char *format, va_list ap) void passt_vsyslog(bool newline, int pri, const char *format, va_list ap)
{ {
char buf[BUFSIZ]; char buf[BUFSIZ];
int n; int n;
@ -188,7 +197,7 @@ void passt_vsyslog(int pri, const char *format, va_list ap)
n += vsnprintf(buf + n, BUFSIZ - n, format, ap); n += vsnprintf(buf + n, BUFSIZ - n, format, ap);
if (format[strlen(format)] != '\n') if (newline && format[strlen(format)] != '\n')
n += snprintf(buf + n, BUFSIZ - n, "\n"); n += snprintf(buf + n, BUFSIZ - n, "\n");
if (log_sock >= 0 && send(log_sock, buf, n, 0) != n && !log_runtime) if (log_sock >= 0 && send(log_sock, buf, n, 0) != n && !log_runtime)
@ -360,11 +369,12 @@ static int logfile_rotate(int fd, const struct timespec *now)
/** /**
* logfile_write() - Write entry to log file, trigger rotation if full * logfile_write() - Write entry to log file, trigger rotation if full
* @newline: Append newline at the end of the message, if missing
* @pri: Facility and level map, same as priority for vsyslog() * @pri: Facility and level map, same as priority for vsyslog()
* @format: Same as vsyslog() format * @format: Same as vsyslog() format
* @ap: Same as vsyslog() ap * @ap: Same as vsyslog() ap
*/ */
void logfile_write(int pri, const char *format, va_list ap) void logfile_write(bool newline, int pri, const char *format, va_list ap)
{ {
struct timespec now; struct timespec now;
char buf[BUFSIZ]; char buf[BUFSIZ];
@ -380,7 +390,7 @@ void logfile_write(int pri, const char *format, va_list ap)
n += vsnprintf(buf + n, BUFSIZ - n, format, ap); n += vsnprintf(buf + n, BUFSIZ - n, format, ap);
if (format[strlen(format)] != '\n') if (newline && format[strlen(format)] != '\n')
n += snprintf(buf + n, BUFSIZ - n, "\n"); n += snprintf(buf + n, BUFSIZ - n, "\n");
if ((log_written + n >= log_size) && logfile_rotate(log_file, &now)) if ((log_written + n >= log_size) && logfile_rotate(log_file, &now))

18
log.h
View file

@ -13,16 +13,16 @@
#define LOGFILE_CUT_RATIO 30 /* When full, cut ~30% size */ #define LOGFILE_CUT_RATIO 30 /* When full, cut ~30% size */
#define LOGFILE_SIZE_MIN (5UL * MAX(BUFSIZ, PAGE_SIZE)) #define LOGFILE_SIZE_MIN (5UL * MAX(BUFSIZ, PAGE_SIZE))
void vlogmsg(int pri, const char *format, va_list ap); void vlogmsg(bool newline, int pri, const char *format, va_list ap);
void logmsg(int pri, const char *format, ...) void logmsg(bool newline, int pri, const char *format, ...)
__attribute__((format(printf, 2, 3))); __attribute__((format(printf, 3, 4)));
void logmsg_perror(int pri, const char *format, ...) void logmsg_perror(int pri, const char *format, ...)
__attribute__((format(printf, 2, 3))); __attribute__((format(printf, 2, 3)));
#define err(...) logmsg( LOG_ERR, __VA_ARGS__) #define err(...) logmsg(true, LOG_ERR, __VA_ARGS__)
#define warn(...) logmsg( LOG_WARNING, __VA_ARGS__) #define warn(...) logmsg(true, LOG_WARNING, __VA_ARGS__)
#define info(...) logmsg( LOG_INFO, __VA_ARGS__) #define info(...) logmsg(true, LOG_INFO, __VA_ARGS__)
#define debug(...) logmsg( LOG_DEBUG, __VA_ARGS__) #define debug(...) logmsg(true, LOG_DEBUG, __VA_ARGS__)
#define err_perror(...) logmsg_perror( LOG_ERR, __VA_ARGS__) #define err_perror(...) logmsg_perror( LOG_ERR, __VA_ARGS__)
#define warn_perror(...) logmsg_perror( LOG_WARNING, __VA_ARGS__) #define warn_perror(...) logmsg_perror( LOG_WARNING, __VA_ARGS__)
@ -54,8 +54,8 @@ void trace_init(int enable);
void __openlog(const char *ident, int option, int facility); void __openlog(const char *ident, int option, int facility);
void logfile_init(const char *name, const char *path, size_t size); void logfile_init(const char *name, const char *path, size_t size);
void passt_vsyslog(int pri, const char *format, va_list ap); void passt_vsyslog(bool newline, int pri, const char *format, va_list ap);
void logfile_write(int pri, const char *format, va_list ap); void logfile_write(bool newline, int pri, const char *format, va_list ap);
void __setlogmask(int mask); void __setlogmask(int mask);
#endif /* LOG_H */ #endif /* LOG_H */