accept the NULL string in the proc message formatting api and simplify

code accordingly.

4 files changed, 37 insertions, 30 deletions

diff --git a/usr.sbin/lpd/engine_lpr.c b/usr.sbin/lpd/engine_lpr.c
index 5de965f3e6a..2d019d89c3b 100644
--- a/usr.sbin/lpd/engine_lpr.c
+++ b/usr.sbin/lpd/engine_lpr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: engine_lpr.c,v 1.1 2018/04/27 16:14:35 eric Exp $	*/
+/*	$OpenBSD: engine_lpr.c,v 1.2 2019/04/04 19:25:45 eric Exp $	*/
 
 /*
  * Copyright (c) 2017 Eric Faurot <eric@openbsd.org>
@@ -302,7 +302,7 @@ lpr_allowedhost_res(uint32_t connid, const char *hostname, const char *reject)
 {
 	m_create(p_frontend, IMSG_LPR_ALLOWEDHOST, connid, 0, -1);
 	m_add_string(p_frontend, hostname);
-	m_add_string(p_frontend, reject ? reject : "");
+	m_add_string(p_frontend, reject);
 	m_close(p_frontend);
 }
 
@@ -426,8 +426,8 @@ static void
 lpr_displayq_res(uint32_t connid, int fd, const char *host, const char *cmd)
 {
 	m_create(p_frontend, IMSG_LPR_DISPLAYQ, connid, 0, fd);
-	m_add_string(p_frontend, host ? host : "");
-	m_add_string(p_frontend, cmd ? cmd : "");
+	m_add_string(p_frontend, host);
+	m_add_string(p_frontend, cmd);
 	m_close(p_frontend);
 }
 
@@ -479,8 +479,8 @@ static void
 lpr_rmjob_res(uint32_t connid, int fd, const char *host, const char *cmd)
 {
 	m_create(p_frontend, IMSG_LPR_RMJOB, connid, 0, fd);
-	m_add_string(p_frontend, host ? host : "");
-	m_add_string(p_frontend, cmd ? cmd : "");
+	m_add_string(p_frontend, host);
+	m_add_string(p_frontend, cmd);
 	m_close(p_frontend);
 }
 
diff --git a/usr.sbin/lpd/frontend_lpr.c b/usr.sbin/lpd/frontend_lpr.c
index ad9c94f92af..778343e6cae 100644
--- a/usr.sbin/lpd/frontend_lpr.c
+++ b/usr.sbin/lpd/frontend_lpr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: frontend_lpr.c,v 1.1 2018/04/27 16:14:35 eric Exp $	*/
+/*	$OpenBSD: frontend_lpr.c,v 1.2 2019/04/04 19:25:45 eric Exp $	*/
 
 /*
  * Copyright (c) 2017 Eric Faurot <eric@openbsd.org>
@@ -159,7 +159,7 @@ lpr_dispatch_engine(struct imsgproc *proc, struct imsg *imsg)
 		m_get_string(proc, &hostname);
 		m_get_string(proc, &reject);
 		m_end(proc);
-		lpr_on_allowedhost(conn, hostname, reject[0] ? reject : NULL);
+		lpr_on_allowedhost(conn, hostname, reject);
 		break;
 
 	case IMSG_LPR_RECVJOB:
@@ -182,8 +182,7 @@ lpr_dispatch_engine(struct imsgproc *proc, struct imsg *imsg)
 		m_get_string(proc, &hostname);
 		m_get_string(proc, &cmd);
 		m_end(proc);
-		lpr_on_request(conn, imsg->fd, hostname[0] ? hostname : NULL,
-		    cmd[0] ? cmd : NULL);
+		lpr_on_request(conn, imsg->fd, hostname, cmd);
 		break;
 
 	default:
diff --git a/usr.sbin/lpd/proc.c b/usr.sbin/lpd/proc.c
index b3aabcb4b59..a7276bddcb3 100644
--- a/usr.sbin/lpd/proc.c
+++ b/usr.sbin/lpd/proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.c,v 1.1 2018/04/27 16:14:37 eric Exp $	*/
+/*	$OpenBSD: proc.c,v 1.2 2019/04/04 19:25:46 eric Exp $	*/
 
 /*
  * Copyright (c) 2017 Eric Faurot <eric@openbsd.org>
@@ -416,7 +416,12 @@ m_add_time(struct imsgproc *p, time_t v)
 void
 m_add_string(struct imsgproc *p, const char *str)
 {
-	m_add(p, str, strlen(str) + 1);
+	if (str) {
+		m_add(p, "s", 1);
+		m_add(p, str, strlen(str) + 1);
+	}
+	else
+		m_add(p, "\0", 1);
 }
 
 void
@@ -485,11 +490,19 @@ m_get_time(struct imsgproc *p, time_t *dst)
 void
 m_get_string(struct imsgproc *p, const char **dst)
 {
-	char *end;
+	char *end, c;
 
 	if (p->m_in.pos >= p->m_in.end)
 		fatalx("%s: no data left", __func__);
 
+	c = *p->m_in.pos++;
+	if (c == '\0') {
+		*dst = NULL;
+		return;
+	}
+
+	if (p->m_in.pos >= p->m_in.end)
+		fatalx("%s: no data left", __func__);
 	end = memchr(p->m_in.pos, 0, p->m_in.end - p->m_in.pos);
 	if (end == NULL)
 		fatalx("%s: unterminated string", __func__);
diff --git a/usr.sbin/lpd/resolver.c b/usr.sbin/lpd/resolver.c
index adcbb13c3b6..5b73e29b618 100644
--- a/usr.sbin/lpd/resolver.c
+++ b/usr.sbin/lpd/resolver.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: resolver.c,v 1.2 2018/09/05 17:32:56 eric Exp $	*/
+/*	$OpenBSD: resolver.c,v 1.3 2019/04/04 19:25:46 eric Exp $	*/
 
 /*
  * Copyright (c) 2017-2018 Eric Faurot <eric@openbsd.org>
@@ -95,7 +95,7 @@ resolver_getaddrinfo(const char *hostname, const char *servname,
 	m_add_int(p_resolver, hints ? hints->ai_socktype : 0);
 	m_add_int(p_resolver, hints ? hints->ai_protocol : 0);
 	m_add_string(p_resolver, hostname);
-	m_add_string(p_resolver, servname ? servname : "");
+	m_add_string(p_resolver, servname);
 	m_close(p_resolver);
 }
 
@@ -150,8 +150,7 @@ resolver_dispatch_request(struct imsgproc *proc, struct imsg *imsg)
 		m_get_int(proc, &hints.ai_socktype);
 		m_get_int(proc, &hints.ai_protocol);
 		m_get_string(proc, &hostname);
-		if (!m_is_eom(proc))
-			m_get_string(proc, &servname);
+		m_get_string(proc, &servname);
 		m_end(proc);
 
 		s = NULL;
@@ -207,6 +206,8 @@ resolver_dispatch_request(struct imsgproc *proc, struct imsg *imsg)
 		m_create(proc, IMSG_GETNAMEINFO, reqid, 0, -1);
 		m_add_int(proc, EAI_SYSTEM);
 		m_add_int(proc, save_errno);
+		m_add_string(proc, NULL);
+		m_add_string(proc, NULL);
 		m_close(proc);
 		break;
 
@@ -254,7 +255,7 @@ resolver_dispatch_result(struct imsgproc *proc, struct imsg *imsg)
 
 		memmove(ai->ai_addr, &ss, ss.ss_len);
 
-		if (cname[0]) {
+		if (cname) {
 			ai->ai_canonname = strdup(cname);
 			if (ai->ai_canonname == NULL) {
 				log_warn("%s: strdup", __func__);
@@ -281,15 +282,12 @@ resolver_dispatch_result(struct imsgproc *proc, struct imsg *imsg)
 	case IMSG_GETNAMEINFO:
 		m_get_int(proc, &gai_errno);
 		m_get_int(proc, &errno);
-		if (gai_errno == 0) {
-			m_get_string(proc, &host);
-			m_get_string(proc, &serv);
-		}
+		m_get_string(proc, &host);
+		m_get_string(proc, &serv);
 		m_end(proc);
 
 		SPLAY_REMOVE(reqtree, &reqs, req);
-		req->cb_ni(req->arg, gai_errno, gai_errno ? NULL : host,
-		    gai_errno ? NULL : serv);
+		req->cb_ni(req->arg, gai_errno, host, serv);
 		free(req);
 		break;
 	}
@@ -319,8 +317,7 @@ resolver_getaddrinfo_cb(struct asr_result *ar, void *arg)
 		m_add_int(s->proc, ai->ai_socktype);
 		m_add_int(s->proc, ai->ai_protocol);
 		m_add_sockaddr(s->proc, ai->ai_addr);
-		m_add_string(s->proc, ai->ai_canonname ?
-		    ai->ai_canonname : "");
+		m_add_string(s->proc, ai->ai_canonname);
 		m_close(s->proc);
 	}
 
@@ -341,10 +338,8 @@ resolver_getnameinfo_cb(struct asr_result *ar, void *arg)
 	m_create(s->proc, IMSG_GETNAMEINFO, s->reqid, 0, -1);
 	m_add_int(s->proc, ar->ar_gai_errno);
 	m_add_int(s->proc, ar->ar_errno);
-	if (ar->ar_gai_errno == 0) {
-		m_add_string(s->proc, s->host);
-		m_add_string(s->proc, s->serv);
-	}
+	m_add_string(s->proc, ar->ar_gai_errno ? NULL : s->host);
+	m_add_string(s->proc, ar->ar_gai_errno ? NULL : s->serv);
 	m_close(s->proc);
 
 	free(s->host);