From 277ed4a605f68118aff9e671f16c0ac6edb1d55a Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Tue, 24 Jul 2012 06:20:05 +0200
Subject: [PATCH] client: Remove sb-compatibility code.

Now that non-client sideband connection attempts are rejected up-front,
we may get rid of all the non-sideband code.
---
 afs.c           |   8 +-
 aft.c           |  59 ++++-----------
 attribute.c     |   5 +-
 blob.c          |   5 +-
 client.h        |   4 +-
 client_common.c | 175 +++++++++++-------------------------------
 command.c       | 198 +++++++++---------------------------------------
 command.h       |   2 -
 para.h          |   8 --
 9 files changed, 99 insertions(+), 365 deletions(-)

diff --git a/afs.c b/afs.c
index eb18708c..da92d6c5 100644
--- a/afs.c
+++ b/afs.c
@@ -607,10 +607,7 @@ int afs_cb_result_handler(struct osl_object *result, uint8_t band,
 	assert(cc);
 	if (!result->size)
 		return 1;
-	if (cc->use_sideband)
-		return send_sb(&cc->scc, result->data, result->size, band,
-			true);
-	return sc_send_bin_buffer(&cc->scc, result->data, result->size);
+	return send_sb(&cc->scc, result->data, result->size, band, true);
 }
 
 int com_select(struct command_context *cc)
@@ -1070,9 +1067,6 @@ int com_init(struct command_context *cc)
 	}
 	ret = send_callback_request(create_tables_callback, &query,
 		afs_cb_result_handler, cc);
-	if (ret < 0 && !cc->use_sideband)
-		/* ignore return value */
-		sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(-ret));
 	return ret;
 }
 
diff --git a/aft.c b/aft.c
index 097b2b59..0cc2bd07 100644
--- a/aft.c
+++ b/aft.c
@@ -1876,12 +1876,8 @@ static int add_one_audio_file(const char *path, void *private_data)
 	ret = 1;
 	if (pb && (pad->flags & ADD_FLAG_LAZY)) { /* lazy is really cheap */
 		if (pad->flags & ADD_FLAG_VERBOSE)
-			send_ret = pad->cc->use_sideband?
-				send_sb_va(&pad->cc->scc, SBD_OUTPUT,
-					"lazy-ignore: %s\n", path)
-			:
-				sc_send_va_buffer(&pad->cc->scc,
-					"lazy-ignore: %s\n", path);
+			send_ret = send_sb_va(&pad->cc->scc, SBD_OUTPUT,
+				"lazy-ignore: %s\n", path);
 		goto out_free;
 	}
 	/* We still want to add this file. Compute its hash. */
@@ -1901,12 +1897,8 @@ static int add_one_audio_file(const char *path, void *private_data)
 	ret = 1;
 	if (pb && hs && hs == pb && !(pad->flags & ADD_FLAG_FORCE)) {
 		if (pad->flags & ADD_FLAG_VERBOSE)
-			send_ret = pad->cc->use_sideband?
-				send_sb_va(&pad->cc->scc, SBD_OUTPUT,
-					"%s exists, not forcing update\n", path)
-			:
-				sc_send_va_buffer(&pad->cc->scc,
-					"%s exists, not forcing update\n", path);
+			send_ret = send_sb_va(&pad->cc->scc, SBD_OUTPUT,
+				"%s exists, not forcing update\n", path);
 		goto out_unmap;
 	}
 	/*
@@ -1923,12 +1915,8 @@ static int add_one_audio_file(const char *path, void *private_data)
 	munmap(map.data, map.size);
 	close(fd);
 	if (pad->flags & ADD_FLAG_VERBOSE) {
-		send_ret = pad->cc->use_sideband?
-			send_sb_va(&pad->cc->scc, SBD_OUTPUT,
-				"adding %s\n", path)
-		:
-			sc_send_va_buffer(&pad->cc->scc,
-				"adding %s\n", path);
+		send_ret = send_sb_va(&pad->cc->scc, SBD_OUTPUT,
+			"adding %s\n", path);
 		if (send_ret < 0)
 			goto out_free;
 	}
@@ -1943,14 +1931,8 @@ out_unmap:
 	munmap(map.data, map.size);
 out_free:
 	if (ret < 0 && send_ret >= 0)
-		send_ret = pad->cc->use_sideband?
-			send_sb_va(&pad->cc->scc, SBD_ERROR_LOG,
-				"failed to add %s (%s)\n", path,
-				para_strerror(-ret))
-		:
-			sc_send_va_buffer(&pad->cc->scc,
-				"failed to add %s (%s)\n", path,
-				para_strerror(-ret));
+		send_ret = send_sb_va(&pad->cc->scc, SBD_ERROR_LOG,
+			"failed to add %s (%s)\n", path, para_strerror(-ret));
 	free(obj.data);
 	clear_afhi(afhi_ptr);
 	/* Stop adding files only on send errors. */
@@ -1994,11 +1976,7 @@ int com_add(struct command_context *cc)
 		char *path;
 		ret = verify_path(cc->argv[i], &path);
 		if (ret < 0) {
-			ret = cc->use_sideband?
-				send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s: %s\n",
-				cc->argv[i], para_strerror(-ret))
-			:
-				sc_send_va_buffer(&cc->scc, "%s: %s\n",
+			ret = send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s: %s\n",
 				cc->argv[i], para_strerror(-ret));
 			if (ret < 0)
 				return ret;
@@ -2006,14 +1984,9 @@ int com_add(struct command_context *cc)
 		}
 		ret = stat(path, &statbuf);
 		if (ret < 0) {
-			ret = cc->use_sideband?
-				send_sb_va(&cc->scc, SBD_ERROR_LOG,
-					"failed to stat %s (%s)\n", path,
-					strerror(errno))
-				:
-				sc_send_va_buffer(&cc->scc,
-					"failed to stat %s (%s)\n", path,
-					strerror(errno));
+			ret = send_sb_va(&cc->scc, SBD_ERROR_LOG,
+				"failed to stat %s (%s)\n", path,
+				strerror(errno));
 			free(path);
 			if (ret < 0)
 				return ret;
@@ -2025,12 +1998,8 @@ int com_add(struct command_context *cc)
 		else
 			ret = add_one_audio_file(path, &pad);
 		if (ret < 0) {
-			if (cc->use_sideband)
-				send_sb_va(&cc->scc, SBD_OUTPUT, "%s: %s\n", path,
-					para_strerror(-ret));
-			else
-				sc_send_va_buffer(&cc->scc, "%s: %s\n", path,
-					para_strerror(-ret));
+			send_sb_va(&cc->scc, SBD_OUTPUT, "%s: %s\n", path,
+				para_strerror(-ret));
 			free(path);
 			return ret;
 		}
diff --git a/attribute.c b/attribute.c
index 96b54c99..5a3861be 100644
--- a/attribute.c
+++ b/attribute.c
@@ -212,10 +212,7 @@ int com_lsatt(struct command_context *cc)
 	if (ret < 0)
 		send_strerror(cc, -ret);
 	else if (ret == 0 && cc->argc > 1)
-		ret = cc->use_sideband?
-			send_sb_va(&cc->scc, SBD_ERROR_LOG, "no matches\n")
-		:
-			sc_send_va_buffer(&cc->scc, "no matches\n");
+		ret = send_sb_va(&cc->scc, SBD_ERROR_LOG, "no matches\n");
 	return ret;
 }
 
diff --git a/blob.c b/blob.c
index 50fae99d..a6ae1acf 100644
--- a/blob.c
+++ b/blob.c
@@ -437,10 +437,7 @@ static int stdin_command(struct command_context *cc, struct osl_object *arg_obj,
 	struct osl_object query, stdin_obj;
 	int ret;
 
-	if (cc->use_sideband)
-		ret = send_sb(&cc->scc, NULL, 0, SBD_AWAITING_DATA, false);
-	else
-		ret = sc_send_buffer(&cc->scc, AWAITING_DATA_MSG);
+	ret = send_sb(&cc->scc, NULL, 0, SBD_AWAITING_DATA, false);
 	if (ret < 0)
 		return ret;
 	ret = fd2buf(&cc->scc, &stdin_obj);
diff --git a/client.h b/client.h
index 92e14b15..0685f33e 100644
--- a/client.h
+++ b/client.h
@@ -34,9 +34,7 @@ struct client_task {
 	int status;
 	/** The file descriptor and the session keys. */
 	struct stream_cipher_context scc;
-	/** True if this connections uses the sideband API. */
-	bool use_sideband;
-	/** The sideband context, ignored if \a use_sideband is false. */
+	/** The sideband context. */
 	struct sb_context *sbc;
 	/** The hash value of the decrypted challenge. */
 	unsigned char *challenge_hash;
diff --git a/client_common.c b/client_common.c
index a3a471ae..cee76f8b 100644
--- a/client_common.c
+++ b/client_common.c
@@ -355,11 +355,7 @@ static void client_post_select(struct sched *s, struct task *t)
 	case CL_RECEIVED_WELCOME: /* send auth command */
 		if (!FD_ISSET(ct->scc.fd, &s->wfds))
 			return;
-		if (has_feature("sideband", ct)) {
-			ct->use_sideband = true;
-			sprintf(buf, AUTH_REQUEST_MSG "%s sideband", ct->user);
-		} else
-			sprintf(buf, AUTH_REQUEST_MSG "%s", ct->user);
+		sprintf(buf, AUTH_REQUEST_MSG "%s sideband", ct->user);
 		PARA_INFO_LOG("--> %s\n", buf);
 		ret = write_buffer(ct->scc.fd, buf);
 		if (ret < 0)
@@ -374,35 +370,23 @@ static void client_post_select(struct sched *s, struct task *t)
 		{
 		/* decrypted challenge/session key buffer */
 		unsigned char crypt_buf[1024];
-		/* the SHA1 of the decrypted challenge */
+		struct sb_buffer sbb;
 
-		if (ct->use_sideband) {
-			struct sb_buffer sbb;
-			ret = recv_sb(ct, &s->rfds, &sbb);
-			if (ret <= 0)
-				goto out;
-			if (sbb.band != SBD_CHALLENGE) {
-				ret = -E_BAD_BAND;
-				free(sbb.iov.iov_base);
-					goto out;
-			}
-			n = sbb.iov.iov_len;
-			PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
-			ret = priv_decrypt(ct->key_file, crypt_buf,
-				sbb.iov.iov_base, n);
+		ret = recv_sb(ct, &s->rfds, &sbb);
+		if (ret <= 0)
+			goto out;
+		if (sbb.band != SBD_CHALLENGE) {
+			ret = -E_BAD_BAND;
 			free(sbb.iov.iov_base);
-			if (ret < 0)
-				goto out;
-		} else {
-			ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
-			if (ret < 0 || n == 0)
-				goto out;
-			PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
-			ret = priv_decrypt(ct->key_file, crypt_buf,
-				(unsigned char *)buf, n);
-			if (ret < 0)
 				goto out;
 		}
+		n = sbb.iov.iov_len;
+		PARA_INFO_LOG("<-- [challenge] (%zu bytes)\n", n);
+		ret = priv_decrypt(ct->key_file, crypt_buf,
+			sbb.iov.iov_base, n);
+		free(sbb.iov.iov_base);
+		if (ret < 0)
+			goto out;
 		ct->challenge_hash = para_malloc(HASH_SIZE);
 		hash_function((char *)crypt_buf, CHALLENGE_SIZE, ct->challenge_hash);
 		ct->scc.send = sc_new(crypt_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
@@ -414,104 +398,50 @@ static void client_post_select(struct sched *s, struct task *t)
 		return;
 		}
 	case CL_RECEIVED_CHALLENGE:
-		if (ct->use_sideband) {
-			ret = send_sb(ct, ct->challenge_hash, HASH_SIZE,
-				SBD_CHALLENGE_RESPONSE, false);
-			if (ret != 0)
-				ct->challenge_hash = NULL;
-			if (ret <= 0)
-				goto out;
-		} else {
-			ret = write_all(ct->scc.fd, (char *)ct->challenge_hash, HASH_SIZE);
-			if (ret < 0)
-				goto out;
-		}
+		ret = send_sb(ct, ct->challenge_hash, HASH_SIZE,
+			SBD_CHALLENGE_RESPONSE, false);
+		if (ret != 0)
+			ct->challenge_hash = NULL;
+		if (ret <= 0)
+			goto out;
 		ct->status = CL_SENT_CH_RESPONSE;
 		goto out;
 	case CL_SENT_CH_RESPONSE: /* read server response */
 		{
-		if (ct->use_sideband) {
-			struct sb_buffer sbb;
-			ret = recv_sb(ct, &s->rfds, &sbb);
-			if (ret <= 0)
-				goto out;
-			free(sbb.iov.iov_base);
-			if (sbb.band != SBD_PROCEED)
-				ret = -E_BAD_BAND;
-			else
-				ct->status = CL_RECEIVED_PROCEED;
-			goto out;
-		}
-		ret = client_recv_buffer(ct, &s->rfds, buf, sizeof(buf), &n);
-		if (ret < 0 || n == 0)
-			goto out;
-		/* check if server has sent "Proceed" message */
-		ret = -E_CLIENT_AUTH;
-		if (n < PROCEED_MSG_LEN)
-			goto out;
-		if (!strstr(buf, PROCEED_MSG))
+		struct sb_buffer sbb;
+		ret = recv_sb(ct, &s->rfds, &sbb);
+		if (ret <= 0)
 			goto out;
-		ct->status = CL_RECEIVED_PROCEED;
-		return;
+		free(sbb.iov.iov_base);
+		if (sbb.band != SBD_PROCEED)
+			ret = -E_BAD_BAND;
+		else
+			ct->status = CL_RECEIVED_PROCEED;
+		goto out;
 		}
 	case CL_RECEIVED_PROCEED: /* concat args and send command */
 		{
-		int i;
-		char *command = NULL;
 		if (!FD_ISSET(ct->scc.fd, &s->wfds))
 			return;
-		if (ct->use_sideband) {
-			ret = send_sb_command(ct);
-			if (ret <= 0)
-				goto out;
-			ct->status = CL_SENT_COMMAND;
-			return;
-		}
-		for (i = 0; i < ct->conf.inputs_num; i++) {
-			char *tmp = command;
-			command = make_message("%s\n%s", command?
-				command : "", ct->conf.inputs[i]);
-			free(tmp);
-		}
-		command = para_strcat(command, EOC_MSG "\n");
-		PARA_DEBUG_LOG("--> %s\n", command);
-		ret = sc_send_buffer(&ct->scc, command);
-		free(command);
-		if (ret < 0)
+		ret = send_sb_command(ct);
+		if (ret <= 0)
 			goto out;
 		ct->status = CL_SENT_COMMAND;
 		return;
 		}
 	case CL_SENT_COMMAND:
 		{
-		char *buf2;
-		if (ct->use_sideband) {
-			struct sb_buffer sbb;
-			ret = recv_sb(ct, &s->rfds, &sbb);
-			if (ret <= 0)
-				goto out;
-			if (sbb.band == SBD_AWAITING_DATA) {
-				ct->status = CL_SENDING;
-				free(sbb.iov.iov_base);
-				goto out;
-			}
-			ct->status = CL_RECEIVING;
-			ret = dispatch_sbb(ct, &sbb);
+		struct sb_buffer sbb;
+		ret = recv_sb(ct, &s->rfds, &sbb);
+		if (ret <= 0)
+			goto out;
+		if (sbb.band == SBD_AWAITING_DATA) {
+			ct->status = CL_SENDING;
+			free(sbb.iov.iov_base);
 			goto out;
 		}
-		/* can not use "buf" here because we need a malloced buffer */
-		buf2 = para_malloc(CLIENT_BUFSIZE);
-		ret = client_recv_buffer(ct, &s->rfds, buf2, CLIENT_BUFSIZE, &n);
-		if (n > 0) {
-			if (strstr(buf2, AWAITING_DATA_MSG)) {
-				free(buf2);
-				ct->status = CL_SENDING;
-				return;
-			}
-			ct->status = CL_RECEIVING;
-			btr_add_output(buf2, n, btrn);
-		} else
-			free(buf2);
+		ct->status = CL_RECEIVING;
+		ret = dispatch_sbb(ct, &sbb);
 		goto out;
 		}
 	case CL_SENDING:
@@ -534,7 +464,7 @@ static void client_post_select(struct sched *s, struct task *t)
 		}
 	case CL_RECEIVING:
 		{
-		char *buf2;
+		struct sb_buffer sbb;
 		ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
 		if (ret < 0)
 			goto out;
@@ -546,31 +476,16 @@ static void client_post_select(struct sched *s, struct task *t)
 		 */
 		if (!FD_ISSET(ct->scc.fd, &s->rfds))
 			return;
-		if (ct->use_sideband) {
-			struct sb_buffer sbb;
-			ret = recv_sb(ct, &s->rfds, &sbb);
-			if (ret > 0)
-				ret = dispatch_sbb(ct, &sbb);
-			goto out;
-		}
-		buf2 = para_malloc(CLIENT_BUFSIZE);
-		ret = client_recv_buffer(ct, &s->rfds, buf2, CLIENT_BUFSIZE, &n);
-		if (n > 0) {
-			buf2 = para_realloc(buf2, n);
-			btr_add_output(buf2, n, btrn);
-		} else
-			free(buf2);
+		ret = recv_sb(ct, &s->rfds, &sbb);
+		if (ret > 0)
+			ret = dispatch_sbb(ct, &sbb);
 		goto out;
 		}
 	}
 out:
 	t->error = ret;
-	if (ret < 0) {
-		if (!ct->use_sideband && ret != -E_SERVER_EOF &&
-				ret != -E_BTR_EOF && ret != -E_EOF)
-			PARA_ERROR_LOG("%s\n", para_strerror(-t->error));
+	if (ret < 0)
 		btr_remove_node(&ct->btrn);
-	}
 }
 
 /**
diff --git a/command.c b/command.c
index 9b279f7d..d4955fb6 100644
--- a/command.c
+++ b/command.c
@@ -269,10 +269,7 @@ __printf_3_4 int send_sb_va(struct stream_cipher_context *scc, int band,
  */
 int send_strerror(struct command_context *cc, int err)
 {
-	return cc->use_sideband?
-		send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err))
-	:
-		sc_send_va_buffer(&cc->scc, "%s\n", para_strerror(err));
+	return send_sb_va(&cc->scc, SBD_ERROR_LOG, "%s\n", para_strerror(err));
 }
 
 /**
@@ -339,23 +336,14 @@ static int com_sender(struct command_context *cc)
 			free(msg);
 			msg = tmp;
 		}
-		if (cc->use_sideband)
-			return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
-		ret = sc_send_buffer(&cc->scc, msg);
-		free(msg);
-		return ret;
+		return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
 	}
 	ret = check_sender_args(cc->argc, cc->argv, &scd);
 	if (ret < 0) {
 		if (scd.sender_num < 0)
 			return ret;
 		msg = senders[scd.sender_num].help();
-		if (cc->use_sideband)
-			return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT,
-				false);
-		ret = sc_send_buffer(&cc->scc, msg);
-		free(msg);
-		return ret;
+		return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
 	}
 
 	switch (scd.cmd_num) {
@@ -417,11 +405,7 @@ static int com_si(struct command_context *cc)
 	mutex_unlock(mmd_mutex);
 	free(ut);
 	free(sender_info);
-	if (cc->use_sideband)
-		return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
-	ret = sc_send_bin_buffer(&cc->scc, msg, ret);
-	free(msg);
-	return ret;
+	return send_sb(&cc->scc, msg, ret, SBD_OUTPUT, false);
 }
 
 /* version */
@@ -435,9 +419,7 @@ static int com_version(struct command_context *cc)
 	msg = VERSION_TEXT("server") "built: " BUILD_DATE "\n" UNAME_RS
 		", " CC_VERSION "\n";
 	len = strlen(msg);
-	if (cc->use_sideband)
-		return send_sb(&cc->scc, msg, len, SBD_OUTPUT, true);
-	return sc_send_bin_buffer(&cc->scc, msg, len);
+	return send_sb(&cc->scc, msg, len, SBD_OUTPUT, true);
 }
 
 #define EMPTY_STATUS_ITEMS \
@@ -541,21 +523,12 @@ static int com_stat(struct command_context *cc)
 	for (;;) {
 		mmd_dup(nmmd);
 		ret = get_status(nmmd, parser_friendly, &s);
-		if (cc->use_sideband)
-			ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
-		else {
-			ret = sc_send_bin_buffer(&cc->scc, s, ret);
-			free(s);
-		}
+		ret = send_sb(&cc->scc, s, ret, SBD_OUTPUT, false);
 		if (ret < 0)
 			goto out;
 		if (nmmd->vss_status_flags & VSS_NEXT) {
 			ret = empty_status_items(parser_friendly, &esi);
-			if (cc->use_sideband)
-				ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT,
-					true);
-			else
-				ret = sc_send_bin_buffer(&cc->scc, esi, ret);
+			ret = send_sb(&cc->scc, esi, ret, SBD_OUTPUT, true);
 			if (ret < 0)
 				goto out;
 		} else
@@ -576,7 +549,6 @@ out:
 static int send_list_of_commands(struct command_context *cc, struct server_command *cmd,
 		const char *handler)
 {
-	int ret;
 	char *msg = NULL;
 
 	for (; cmd->name; cmd++) {
@@ -587,11 +559,7 @@ static int send_list_of_commands(struct command_context *cc, struct server_comma
 		msg = para_strcat(msg, tmp);
 		free(tmp);
 	}
-	if (cc->use_sideband)
-		return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
-	ret = sc_send_buffer(&cc->scc, msg);
-	free(msg);
-	return ret;
+	return send_sb(&cc->scc, msg, strlen(msg), SBD_OUTPUT, false);
 }
 
 /* returns string that must be freed by the caller */
@@ -647,11 +615,7 @@ static int com_help(struct command_context *cc)
 	);
 	free(perms);
 	free(handler);
-	if (cc->use_sideband)
-		return send_sb(&cc->scc, buf, ret, SBD_OUTPUT, false);
-	ret = sc_send_buffer(&cc->scc, buf);
-	free(buf);
-	return ret;
+	return send_sb(&cc->scc, buf, ret, SBD_OUTPUT, false);
 }
 
 /* hup */
@@ -813,58 +777,6 @@ static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
 	return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
 }
 
-/*
- * Parse first string from *cmd and lookup in table of valid commands.
- * On error, NULL is returned.
- */
-static struct server_command *parse_cmd(const char *cmdstr)
-{
-	char buf[255];
-	int n = 0;
-
-	sscanf(cmdstr, "%200s%n", buf, &n);
-	if (!n)
-		return NULL;
-	buf[n] = '\0';
-	return get_cmd_ptr(buf, NULL);
-}
-
-static int read_command(struct stream_cipher_context *scc, char **result)
-{
-	int ret;
-	char buf[4096];
-	char *command = NULL;
-
-	for (;;) {
-		size_t numbytes;
-		char *p;
-
-		ret = sc_recv_buffer(scc, buf, sizeof(buf));
-		if (ret < 0)
-			goto out;
-		if (!ret)
-			break;
-		numbytes = ret;
-		ret = -E_COMMAND_SYNTAX;
-		if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
-			goto out;
-		command = para_strcat(command, buf);
-		p = strstr(command, EOC_MSG);
-		if (p) {
-			*p = '\0';
-			break;
-		}
-	}
-	ret = command? 1 : -E_COMMAND_SYNTAX;
-out:
-	if (ret < 0)
-		free(command);
-	else
-		*result = command;
-	return ret;
-
-}
-
 static void reset_signals(void)
 {
 	para_sigaction(SIGCHLD, SIG_IGN);
@@ -873,15 +785,14 @@ static void reset_signals(void)
 	para_sigaction(SIGHUP, SIG_DFL);
 }
 
-static int parse_auth_request(char *buf, int len, struct user **u,
-		bool *use_sideband)
+static int parse_auth_request(char *buf, int len, struct user **u)
 {
 	int ret;
 	char *p, *username, **features = NULL;
 	size_t auth_rq_len = strlen(AUTH_REQUEST_MSG);
+	bool sideband_requested = false;
 
 	*u = NULL;
-	*use_sideband = false;
 	if (len < auth_rq_len + 2)
 		return -E_AUTH_REQUEST;
 	if (strncmp(buf, AUTH_REQUEST_MSG, auth_rq_len) != 0)
@@ -897,20 +808,19 @@ static int parse_auth_request(char *buf, int len, struct user **u,
 		create_argv(p, ",", &features);
 		for (i = 0; features[i]; i++) {
 			if (strcmp(features[i], "sideband") == 0)
-				*use_sideband = true;
+				sideband_requested = true;
 			else {
 				ret = -E_BAD_FEATURE;
 				goto out;
 			}
 		}
 	}
-	if (*use_sideband == false) { /* sideband is mandatory */
+	if (sideband_requested == false) { /* sideband is mandatory */
 		PARA_ERROR_LOG("client did not request sideband\n");
 		ret = -E_BAD_FEATURE;
 		goto out;
 	}
-	PARA_DEBUG_LOG("received auth request for user %s (sideband = %s)\n",
-		username, *use_sideband? "true" : "false");
+	PARA_DEBUG_LOG("received auth request for user %s\n", username);
 	*u = lookup_user(username);
 	ret = 1;
 out:
@@ -987,6 +897,7 @@ __noreturn void handle_connect(int fd, const char *peername)
 	char *p, *command = NULL, *buf = para_malloc(HANDSHAKE_BUFSIZE) /* must be on the heap */;
 	size_t numbytes;
 	struct command_context cc_struct = {.peer = peername}, *cc = &cc_struct;
+	struct iovec iov;
 
 	cc->scc.fd = fd;
 	reset_signals();
@@ -1005,7 +916,7 @@ __noreturn void handle_connect(int fd, const char *peername)
 	ret = recv_buffer(fd, buf, HANDSHAKE_BUFSIZE);
 	if (ret < 0)
 		goto net_err;
-	ret = parse_auth_request(buf, ret, &cc->u, &cc->use_sideband);
+	ret = parse_auth_request(buf, ret, &cc->u);
 	if (ret < 0)
 		goto net_err;
 	p = buf + strlen(AUTH_REQUEST_MSG);
@@ -1029,28 +940,16 @@ __noreturn void handle_connect(int fd, const char *peername)
 	}
 	PARA_DEBUG_LOG("sending %u byte challenge + rc4 keys (%zu bytes)\n",
 		CHALLENGE_SIZE, numbytes);
-	if (cc->use_sideband) {
-		struct iovec iov;
-		ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
-		buf = NULL;
-		if (ret < 0)
-			goto net_err;
-		ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
-			HANDSHAKE_BUFSIZE, &iov);
-		if (ret < 0)
-			goto net_err;
-		buf = iov.iov_base;
-		numbytes = iov.iov_len;
-	} else {
-		ret = write_all(fd, buf, numbytes);
-		if (ret < 0)
-			goto net_err;
-		/* recv challenge response */
-		ret = recv_bin_buffer(fd, buf, HASH_SIZE);
-		if (ret < 0)
-			goto net_err;
-		numbytes = ret;
-	}
+	ret = send_sb(&cc->scc, buf, numbytes, SBD_CHALLENGE, false);
+	buf = NULL;
+	if (ret < 0)
+		goto net_err;
+	ret = recv_sb(&cc->scc, SBD_CHALLENGE_RESPONSE,
+		HANDSHAKE_BUFSIZE, &iov);
+	if (ret < 0)
+		goto net_err;
+	buf = iov.iov_base;
+	numbytes = iov.iov_len;
 	PARA_DEBUG_LOG("received %zu bytes challenge response\n", numbytes);
 	ret = -E_BAD_USER;
 	if (!cc->u)
@@ -1071,41 +970,16 @@ __noreturn void handle_connect(int fd, const char *peername)
 	/* init stream cipher keys with the second part of the random buffer */
 	cc->scc.recv = sc_new(rand_buf + CHALLENGE_SIZE, SESSION_KEY_LEN);
 	cc->scc.send = sc_new(rand_buf + CHALLENGE_SIZE + SESSION_KEY_LEN, SESSION_KEY_LEN);
-	if (cc->use_sideband)
-		ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
-	else
-		ret = sc_send_buffer(&cc->scc, PROCEED_MSG);
+	ret = send_sb(&cc->scc, NULL, 0, SBD_PROCEED, false);
 	if (ret < 0)
 		goto net_err;
-	if (cc->use_sideband) {
-		struct iovec iov;
-		ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
-		if (ret < 0)
-			goto net_err;
-		ret = parse_sb_command(cc, &iov);
-		if (ret < 0)
-			goto err_out;
-		cc->argc = ret;
-	} else {
-		ret = read_command(&cc->scc, &command);
-		if (ret == -E_COMMAND_SYNTAX)
-			goto err_out;
-		if (ret < 0)
-			goto net_err;
-		ret = -E_BAD_CMD;
-		cc->cmd = parse_cmd(command);
-		if (!cc->cmd)
-			goto err_out;
-		/* valid command, check permissions */
-		ret = check_perms(cc->u->perms, cc->cmd);
-		if (ret < 0)
-			goto err_out;
-		/* valid command and sufficient perms */
-		ret = create_argv(command, "\n", &cc->argv);
-		if (ret < 0)
-			goto err_out;
-		cc->argc = ret;
-	}
+	ret = recv_sb(&cc->scc, SBD_COMMAND, MAX_COMMAND_LEN, &iov);
+	if (ret < 0)
+		goto net_err;
+	ret = parse_sb_command(cc, &iov);
+	if (ret < 0)
+		goto err_out;
+	cc->argc = ret;
 	PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cc->cmd->name,
 		cc->u->name, peername);
 	ret = cc->cmd->handler(cc);
@@ -1116,7 +990,7 @@ __noreturn void handle_connect(int fd, const char *peername)
 	if (ret >= 0)
 		goto out;
 err_out:
-	if (send_strerror(cc, -ret) >= 0 && cc->use_sideband)
+	if (send_strerror(cc, -ret) >= 0)
 		send_sb(&cc->scc, NULL, 0, SBD_EXIT__FAILURE, true);
 net_err:
 	PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
@@ -1128,7 +1002,7 @@ out:
 		mmd->events++;
 	mmd->active_connections--;
 	mutex_unlock(mmd_mutex);
-	if (ret >= 0 && cc->use_sideband) {
+	if (ret >= 0) {
 		ret = send_sb(&cc->scc, NULL, 0, SBD_EXIT__SUCCESS, true);
 		if (ret < 0)
 			PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
diff --git a/command.h b/command.h
index e4159e6b..6d220207 100644
--- a/command.h
+++ b/command.h
@@ -14,8 +14,6 @@ struct command_context {
 	struct server_command *cmd;
 	/** File descriptor and crypto keys. */
 	struct stream_cipher_context scc;
-	/** Whether to use the sideband API for this command. */
-	bool use_sideband;
 };
 
 /**
diff --git a/para.h b/para.h
index 4208ae6a..46efebde 100644
--- a/para.h
+++ b/para.h
@@ -82,14 +82,6 @@ extern __printf_2_3 void (*para_log)(int, const char*, ...);
 
 /** Sent by para_client to initiate the authentication procedure. */
 #define AUTH_REQUEST_MSG "auth rsa "
-/** Sent by para_server for commands that expect a data file. */
-#define AWAITING_DATA_MSG "\nAwaiting Data."
-/** Sent by para_server if authentication was successful. */
-#define PROCEED_MSG "Proceed."
-/** Length of the \p PROCEED_MSG string. */
-#define PROCEED_MSG_LEN strlen(PROCEED_MSG)
-/** Sent by para_client to indicate the end of the command line. */
-#define EOC_MSG "\nEnd of Command."
 
 /* exec */
 int para_exec_cmdline_pid(pid_t *pid, const char *cmdline, int *fds);
-- 
2.39.5