I like all of these changes.
> We have the same limit for syslog lines in libc, kernel, syslogd
> now. Do we want a common constant? Is the name LOG_MAXLINE suitable
> as a global name? Most constants in sys/syslog.h start with LOG_.
>
> While there I renamed TBUF_LEN and FMT_LEN to _SIZE as they contain
> a NUL byte. Change FMT_SIZE to 1024+1 for consistency. And it
> does not make sense to loop over the format string if there is no
> output space left.
>
> ok?
>
> bluhm
>
> Index: sys/kern/subr_log.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/sys/kern/subr_log.c,v
> retrieving revision 1.51
> diff -u -p -r1.51 subr_log.c
> --- sys/kern/subr_log.c 18 Jul 2017 22:22:19 -0000 1.51
> +++ sys/kern/subr_log.c 19 Jul 2017 00:08:25 -0000
> @@ -418,8 +418,8 @@ dosendsyslog(struct proc *p, const char
> size_t i, len;
> int error;
>
> - if (nbyte > 8192)
> - nbyte = 8192;
> + if (nbyte > LOG_MAXLINE)
> + nbyte = LOG_MAXLINE;
>
> /* Global variable syslogf may change during sleep, use local copy. */
> fp = syslogf;
> Index: sys/sys/syslog.h
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/sys/sys/syslog.h,v
> retrieving revision 1.15
> diff -u -p -r1.15 syslog.h
> --- sys/sys/syslog.h 14 Jul 2014 03:52:04 -0000 1.15
> +++ sys/sys/syslog.h 19 Jul 2017 00:05:05 -0000
> @@ -39,6 +39,8 @@
>
> #define LIOCSFD _IOW('l', 127, int) /* set sendsyslog() fd
> */
>
> +#define LOG_MAXLINE 8192 /* maximum line length */
> +
> /*
> * priorities/facilities are encoded into a single 32-bit quantity, where the
> * bottom 3 bits are the priority (0-7) and the top 28 bits are the facility
> Index: lib/libc/gen/syslog_r.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/lib/libc/gen/syslog_r.c,v
> retrieving revision 1.16
> diff -u -p -r1.16 syslog_r.c
> --- lib/libc/gen/syslog_r.c 19 Oct 2016 16:09:24 -0000 1.16
> +++ lib/libc/gen/syslog_r.c 18 Jul 2017 23:50:13 -0000
> @@ -73,9 +73,9 @@ __vsyslog_r(int pri, struct syslog_data
> int cnt;
> char ch, *p, *t;
> int saved_errno;
> -#define TBUF_LEN (8192+1)
> -#define FMT_LEN 1024
> - char *conp = NULL, *stdp = NULL, tbuf[TBUF_LEN], fmt_cpy[FMT_LEN];
> +#define TBUF_SIZE (LOG_MAXLINE+1)
> +#define FMT_SIZE (1024+1)
> + char *conp = NULL, *stdp = NULL, tbuf[TBUF_SIZE], fmt_cpy[FMT_SIZE];
> int tbuf_left, fmt_left, prlen;
>
> #define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
> @@ -98,7 +98,7 @@ __vsyslog_r(int pri, struct syslog_data
> pri |= data->log_fac;
>
> p = tbuf;
> - tbuf_left = TBUF_LEN;
> + tbuf_left = TBUF_SIZE;
>
> #define DEC() \
> do { \
> @@ -138,7 +138,9 @@ __vsyslog_r(int pri, struct syslog_data
> }
> }
>
> - for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt); ++fmt) {
> + for (t = fmt_cpy, fmt_left = FMT_SIZE;
> + (ch = *fmt) != '\0' && fmt_left > 1;
> + ++fmt) {
> if (ch == '%' && fmt[1] == 'm') {
> char ebuf[NL_TEXTMAX];
>
> @@ -152,15 +154,13 @@ __vsyslog_r(int pri, struct syslog_data
> t += prlen;
> fmt_left -= prlen;
> } else if (ch == '%' && fmt[1] == '%' && fmt_left > 2) {
> + ++fmt;
> *t++ = '%';
> *t++ = '%';
> - fmt++;
> fmt_left -= 2;
> } else {
> - if (fmt_left > 1) {
> - *t++ = ch;
> - fmt_left--;
> - }
> + *t++ = ch;
> + fmt_left--;
> }
> }
> *t = '\0';
> Index: usr.sbin/syslogd/syslogd.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/usr.sbin/syslogd/syslogd.c,v
> retrieving revision 1.244
> diff -u -p -r1.244 syslogd.c
> --- usr.sbin/syslogd/syslogd.c 28 Apr 2017 14:52:13 -0000 1.244
> +++ usr.sbin/syslogd/syslogd.c 19 Jul 2017 00:03:27 -0000
> @@ -54,7 +54,7 @@
> */
>
> #define MAX_UDPMSG 1180 /* maximum UDP send size */
> -#define MIN_MEMBUF (MAXLINE * 4) /* Minimum memory buffer size */
> +#define MIN_MEMBUF (LOG_MAXLINE * 4) /* Minimum memory buffer size */
> #define MAX_MEMBUF (256 * 1024) /* Maximum memory buffer size */
> #define MAX_MEMBUF_NAME 64 /* Max length of membuf log
> name */
> #define MAX_TCPBUF (256 * 1024) /* Maximum tcp event buffer size */
> @@ -492,8 +492,8 @@ main(int argc, char *argv[])
>
> /* Reserve space for kernel message buffer plus buffer full message. */
> linesize = getmsgbufsize() + 64;
> - if (linesize < MAXLINE)
> - linesize = MAXLINE;
> + if (linesize < LOG_MAXLINE)
> + linesize = LOG_MAXLINE;
> linesize++;
> if ((linebuf = malloc(linesize)) == NULL)
> fatal("allocate line buffer");
> @@ -1011,7 +1011,8 @@ udp_readcb(int fd, short event, void *ar
> ssize_t n;
>
> salen = sizeof(sa);
> - n = recvfrom(fd, linebuf, MAXLINE, 0, (struct sockaddr *)&sa, &salen);
> + n = recvfrom(fd, linebuf, LOG_MAXLINE, 0, (struct sockaddr *)&sa,
> + &salen);
> if (n > 0) {
> char resolve[NI_MAXHOST];
>
> @@ -1031,7 +1032,8 @@ unix_readcb(int fd, short event, void *a
> ssize_t n;
>
> salen = sizeof(sa);
> - n = recvfrom(fd, linebuf, MAXLINE, 0, (struct sockaddr *)&sa, &salen);
> + n = recvfrom(fd, linebuf, LOG_MAXLINE, 0, (struct sockaddr *)&sa,
> + &salen);
> if (n > 0) {
> linebuf[n] = '\0';
> printline(LocalHostName, linebuf);
> @@ -1265,15 +1267,15 @@ tcp_readcb(struct bufferevent *bufev, vo
> if (len > 0 && msg[len-1] == '\n')
> msg[len-1] = '\0';
> if (len == 0 || msg[len-1] != '\0') {
> - memcpy(linebuf, msg, MINIMUM(len, MAXLINE));
> - linebuf[MINIMUM(len, MAXLINE)] = '\0';
> + memcpy(linebuf, msg, MINIMUM(len, LOG_MAXLINE));
> + linebuf[MINIMUM(len, LOG_MAXLINE)] = '\0';
> msg = linebuf;
> }
> printline(p->p_hostname, msg);
> evbuffer_drain(bufev->input, len);
> }
> /* Maximum frame has 5 digits, 1 space, MAXLINE chars, 1 new line. */
> - if (EVBUFFER_LENGTH(bufev->input) >= 5 + 1 + MAXLINE + 1) {
> + if (EVBUFFER_LENGTH(bufev->input) >= 5 + 1 + LOG_MAXLINE + 1) {
> log_debug(", use %zu bytes", EVBUFFER_LENGTH(bufev->input));
> printline(p->p_hostname, EVBUFFER_DATA(bufev->input));
> evbuffer_drain(bufev->input, -1);
> @@ -1558,7 +1560,7 @@ void
> printline(char *hname, char *msg)
> {
> int pri;
> - char *p, *q, line[MAXLINE + 4 + 1]; /* message, encoding, NUL */
> + char *p, *q, line[LOG_MAXLINE + 4 + 1]; /* message, encoding, NUL */
>
> /* test for special codes */
> pri = DEFUPRI;
> @@ -1575,13 +1577,13 @@ printline(char *hname, char *msg)
> if (LOG_FAC(pri) == LOG_KERN)
> pri = LOG_USER | LOG_PRI(pri);
>
> - for (q = line; *p && q < &line[MAXLINE]; p++) {
> + for (q = line; *p && q < &line[LOG_MAXLINE]; p++) {
> if (*p == '\n')
> *q++ = ' ';
> else
> q = vis(q, *p, 0, 0);
> }
> - line[MAXLINE] = *q = '\0';
> + line[LOG_MAXLINE] = *q = '\0';
>
> logline(pri, 0, hname, line);
> }
> @@ -1593,7 +1595,7 @@ void
> printsys(char *msg)
> {
> int c, pri, flags;
> - char *lp, *p, *q, line[MAXLINE + 1];
> + char *lp, *p, *q, line[LOG_MAXLINE + 1];
> size_t prilen;
>
> (void)snprintf(line, sizeof line, "%s: ", _PATH_UNIX);
> @@ -1855,7 +1857,7 @@ fprintlog(struct filed *f, int flags, ch
> struct iovec iov[6];
> struct iovec *v;
> int l, retryonce;
> - char line[MAXLINE + 1], repbuf[80], greetings[500];
> + char line[LOG_MAXLINE + 1], repbuf[80], greetings[500];
>
> v = iov;
> if (f->f_type == F_WALL) {
> @@ -2496,7 +2498,7 @@ cfline(char *line, char *progblock, char
> int i, pri;
> size_t rb_len;
> char *bp, *p, *q, *proto, *host, *port, *ipproto;
> - char buf[MAXLINE];
> + char buf[LOG_MAXLINE];
> struct filed *xf, *f, *d;
> struct timeval to;
>
> @@ -2946,7 +2948,7 @@ unix_socket(char *path, int type, mode_t
> return (-1);
> }
>
> - optval = MAXLINE + PATH_MAX;
> + optval = LOG_MAXLINE + PATH_MAX;
> if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &optval, sizeof(optval))
> == -1)
> log_warn("setsockopt unix \"%s\"", path);
> @@ -2964,7 +2966,7 @@ double_sockbuf(int fd, int optname)
> if (getsockopt(fd, SOL_SOCKET, optname, &oldsize, &len) == -1)
> log_warn("getsockopt bufsize");
> len = sizeof(newsize);
> - newsize = MAXLINE + 128; /* data + control */
> + newsize = LOG_MAXLINE + 128; /* data + control */
> /* allow 8 full length messages */
> for (i = 0; i < 4; i++, newsize *= 2) {
> if (newsize <= oldsize)
> Index: usr.sbin/syslogd/syslogd.h
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/usr.sbin/syslogd/syslogd.h,v
> retrieving revision 1.30
> diff -u -p -r1.30 syslogd.h
> --- usr.sbin/syslogd/syslogd.h 5 Apr 2017 22:15:35 -0000 1.30
> +++ usr.sbin/syslogd/syslogd.h 19 Jul 2017 00:03:27 -0000
> @@ -48,7 +48,6 @@ extern int nunix;
> extern char **path_unix;
> extern char *path_ctlsock;
>
> -#define MAXLINE 8192 /* maximum line length */
> #define ERRBUFSIZE 256
> void vlogmsg(int pri, const char *, const char *, va_list);
> __dead void die(int);
> Index: usr.sbin/syslogd/ttymsg.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/usr.sbin/syslogd/ttymsg.c,v
> retrieving revision 1.15
> diff -u -p -r1.15 ttymsg.c
> --- usr.sbin/syslogd/ttymsg.c 5 Apr 2017 21:55:31 -0000 1.15
> +++ usr.sbin/syslogd/ttymsg.c 19 Jul 2017 00:03:27 -0000
> @@ -31,6 +31,7 @@
> */
>
> #include <sys/stat.h>
> +#include <sys/syslog.h>
>
> #include <dirent.h>
> #include <errno.h>
> @@ -52,7 +53,7 @@
> struct tty_delay {
> struct event td_event;
> size_t td_length;
> - char td_line[MAXLINE];
> + char td_line[LOG_MAXLINE];
> };
> int tty_delayed = 0;
> void ttycb(int, short, void *);
> @@ -148,8 +149,8 @@ ttymsg(struct iovec *iov, int iovcnt, ch
> break;
> }
> td->td_length = 0;
> - if (left > MAXLINE)
> - left = MAXLINE;
> + if (left > LOG_MAXLINE)
> + left = LOG_MAXLINE;
> while (iovcnt && left) {
> if (iov->iov_len > left)
> iov->iov_len = left;
>
