vmcp: Use libvmcp and remove local vmcp code

Use the new libvmcp.a to send commands to z/VM CP.
The error messages remain unchanged.

Local header file vmcp.h now only contains variable definitions
and some defines used by vmcp.c. Move them to the source file
and remove the now empty header file.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Reviewed-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

vmcp/Makefile

@@ -2,7 +2,9 @@ include ../common.mak
 
 all: vmcp
 
-vmcp: vmcp.o
+libs =	$(rootdir)/libvmcp/libvmcp.a $(rootdir)/libutil/libutil.a
+
+vmcp: vmcp.o $(libs)
 
 install: all
 	$(INSTALL) -d -m 755 $(DESTDIR)$(BINDIR) $(DESTDIR)$(MANDIR)/man8

vmcp/vmcp.c

@@ -28,12 +28,48 @@
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <sys/param.h>
 #include <unistd.h>
 
-#include "vmcp.h"
+#include "lib/zt_common.h"
+#include "lib/vmcp.h"
+
+#define MAXBUFFER 1048576
+#define MINBUFFER 4096
+#define MAXCMDLEN 240
+
+#define VMCP_OK 0
+#define VMCP_CP 1
+#define VMCP_BUF 2
+#define VMCP_LIN 3
+#define VMCP_OPT 4
+
+static struct option options[] = {
+	{"help", no_argument, NULL, 'h'},
+	{"version", no_argument, NULL, 'v'},
+	{"keepcase", no_argument, NULL, 'k'},
+	{"buffer", required_argument, NULL, 'b'},
+	{NULL, 0, NULL, 0}
+};
+
+static const char opt_string[] = "+hvkb:";
+
+static const char help_text[] =
+    "Usage:\n"
+    "vmcp [-k] [-b <size>] command\n"
+    "vmcp [-h|-v]\n\n"
+    "Options:\n"
+    "-h or --help     :Print usage information, then exit\n"
+    "-v or --version  :Print version information, then exit\n"
+    "-k or --keepcase :Using this option, vmcp does not convert the command\n"
+    "                  to uppercase. The default is to translate the command\n"
+    "                  string.\n"
+    "-b <size> or     :defines the buffer size for the response\n"
+    "--buffer=<size>   valid values are from 4096 to 1048576 bytes\n"
+    "                  the k and M suffixes are also supported\n";
 
 static int keep_case = 0;
-static int buffersize = 8192;
+static int buffersize = VMCP_DEFAULT_BUFSZ;
 static char command[MAXCMDLEN + 1];
 
 static void print_help(const char *name)
@@ -48,14 +84,6 @@ static void print_version(const char *name)
 	       name, RELEASE_STRING);
 }
 
-static void uppercase(char *string)
-{
-	while (*string != '\0') {
-		*string = toupper(*string);
-		string++;
-	}
-}
-
 /* Parse STRING for buffer size in bytes, allowing size modifier suffix 'k' and
  * 'm'. Return buffer size in bytes on success, -1 on error. */
 static long parse_buffersize(char *string)
@@ -148,25 +176,6 @@ static inline void linux_error(const char *message)
 	fprintf(stderr, "Error: %s: %s\n", message, strerror(errno));
 }
 
-/* Read at most COUNT bytes from FD into memory at location BUF. Return
- * number of bytes read on success, -1 on error. */
-static ssize_t read_buffer(int fd, char *buf, size_t count)
-{
-	ssize_t ret;
-	ssize_t done;
-
-	for (done = 0; done < (ssize_t) count; done += ret) {
-		ret = read(fd, &buf[done], count - done);
-		if (ret == -1 && errno == EINTR)
-			continue;
-		if (ret == -1)
-			return -1;
-		if (ret == 0)
-			break;
-	}
-	return done;
-}
-
 /* Write COUNT bytes to FD from memory at location BUF. Return number of bytes
  * written on success, -1 otherwise. */
 static ssize_t write_buffer(int fd, const char *buf, size_t count)
@@ -188,77 +197,51 @@ static ssize_t write_buffer(int fd, const char *buf, size_t count)
 
 int main(int argc, char **argv)
 {
+	struct vmcp_parm cp;
 	int ret;
-	int fd;
-	int response_code;
-	int response_size;
-	char *buffer;
 
 	ret = parse_args(argc, argv);
 	if (ret != VMCP_OK)
 		return ret;
 
-	if (!keep_case)
-		uppercase(command);
+	cp.buffer_size = buffersize;
+	cp.cpcmd = command;
+	cp.do_upper = !keep_case;
 
-	buffer = malloc(buffersize);
-	if (!buffer) {
-		linux_error("Could not allocate return buffer");
+	ret = vmcp(&cp);
+
+	switch (ret) {
+	case VMCP_ERR_OPEN:
+		linux_error("Could not open device " VMCP_DEVICE_NODE);
 		return VMCP_LIN;
-	}
-	fd = open(DEVICE_NODE, O_RDWR);
-	if (fd == -1) {
-		linux_error("Could not open device " DEVICE_NODE);
-		free(buffer);
-		return VMCP_LIN;
-	}
-	if (ioctl(fd, VMCP_SETBUF, &buffersize) == -1) {
+	case VMCP_ERR_SETBUF:
 		linux_error("Could not set buffer size");
-		free(buffer);
-		close(fd);
 		return VMCP_LIN;
-	}
-	if (write(fd, command, strlen(command)) == -1) {
+	case VMCP_ERR_WRITE:
 		linux_error("Could not issue CP command");
-		free(buffer);
-		close(fd);
 		return VMCP_LIN;
-	}
-	if (ioctl(fd, VMCP_GETCODE, &response_code) == -1) {
+	case VMCP_ERR_GETCODE:
 		linux_error("Could not query return code");
-		free(buffer);
-		close(fd);
 		return VMCP_LIN;
-	}
-	if (ioctl(fd, VMCP_GETSIZE, &response_size) == -1) {
+	case VMCP_ERR_GETSIZE:
 		linux_error("Could not query response size");
-		free(buffer);
-		close(fd);
 		return VMCP_LIN;
-	}
-	ret = read_buffer(fd, buffer, buffersize);
-	if (ret == -1) {
+	case VMCP_ERR_READ:
 		linux_error("Could not read CP response");
-		free(buffer);
-		close(fd);
 		return VMCP_LIN;
 	}
-	write_buffer(STDOUT_FILENO, buffer, ret);
-	if (response_size > buffersize) {
+	write_buffer(STDOUT_FILENO, cp.response,
+		     MIN(cp.response_size, cp.buffer_size));
+	free(cp.response);
+	if (ret == VMCP_ERR_TOOSMALL) {
 		fprintf(stderr, "Error: output (%d bytes) was truncated, try "
-			"--buffer to increase size\n", response_size);
-		free(buffer);
-		close(fd);
+			"--buffer to increase size\n", cp.response_size);
 		return VMCP_BUF;
 	}
-	if (response_code > 0) {
+	if (cp.cprc > 0) {
 		fprintf(stderr, "Error: non-zero CP response for command '%s': "
-			"#%d\n", command, response_code);
-		free(buffer);
-		close(fd);
+			"#%d\n", command, cp.cprc);
 		return VMCP_CP;
 	}
-	free(buffer);
-	close(fd);
 	return VMCP_OK;
 }

vmcp/vmcp.h

@@ -1,59 +0,0 @@
-/*
- * vmcp - Send commands to the z/VM control program
- *
- * Definitions used by vmcp
- *
- * Copyright IBM Corp. 2005, 2017
- *
- * s390-tools is free software; you can redistribute it and/or modify
- * it under the terms of the MIT license. See LICENSE for details.
- */
-
-#ifndef __vmcp_h__
-#define __vmcp_h__
-
-#include <getopt.h>
-#include <sys/ioctl.h>
-
-#include "lib/zt_common.h"
-
-#define DEVICE_NODE "/dev/vmcp"
-
-#define VMCP_GETCODE _IOR(0x10, 1, int)
-#define VMCP_SETBUF _IOW(0x10, 2, int)
-#define VMCP_GETSIZE _IOR(0x10, 3, int)
-
-#define MAXBUFFER 1048576
-#define MINBUFFER 4096
-#define MAXCMDLEN 240
-
-#define VMCP_OK 0
-#define VMCP_CP 1
-#define VMCP_BUF 2
-#define VMCP_LIN 3
-#define VMCP_OPT 4
-
-static struct option options[] = {
-	{"help", no_argument, NULL, 'h'},
-	{"version", no_argument, NULL, 'v'},
-	{"keepcase", no_argument, NULL, 'k'},
-	{"buffer", required_argument, NULL, 'b'},
-	{NULL, 0, NULL, 0}
-};
-
-static const char opt_string[] = "+hvkb:";
-
-static const char help_text[] =
-    "Usage:\n"
-    "vmcp [-k] [-b <size>] command\n"
-    "vmcp [-h|-v]\n\n"
-    "Options:\n"
-    "-h or --help     :Print usage information, then exit\n"
-    "-v or --version  :Print version information, then exit\n"
-    "-k or --keepcase :Using this option, vmcp does not convert the command\n"
-    "                  to uppercase. The default is to translate the command\n"
-    "                  string.\n"
-    "-b <size> or     :defines the buffer size for the response\n"
-    "--buffer=<size>   valid values are from 4096 to 1048576 bytes\n"
-    "                  the k and M suffixes are also supported\n";
-#endif