[PATCH v2 5/6] i2cset: Get command/mode before reading data

[Guenter Roeck <guenter.roeck-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>]

Get and validate the command/mode parameter for all commands
before reading and evaluating actual data.

Signed-off-by: Guenter Roeck <guenter.roeck-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
---
 tools/i2cset.c |   99 +++++++++++++++++++++++++++++++-------------------------
 1 files changed, 55 insertions(+), 44 deletions(-)

diff --git a/tools/i2cset.c b/tools/i2cset.c
index a45a829..ed6ada2 100644
--- a/tools/i2cset.c
+++ b/tools/i2cset.c
@@ -207,18 +207,37 @@ int main(int argc, char *argv[])
 		help();
 	}
 
-	/* check for block data */
-	len = 0;
-	if (argc > flags + 5) {
+	/* check for command/mode */
+	if (argc == flags + 4) {
+		/* Implicit "c" */
+		size = I2C_SMBUS_BYTE;
+	} else if (argc == flags + 5) {
+		/* "c", "cp",  or implicit "b" */
+		if (!strcmp(argv[flags+4], "c")
+		 || !strcmp(argv[flags+4], "cp")) {
+			size = I2C_SMBUS_BYTE;
+			pec = argv[flags+4][1] == 'p';
+		} else {
+			size = I2C_SMBUS_BYTE_DATA;
+		}
+	} else {
+		/* All other commands */
+		if (strlen(argv[argc-1]) > 2
+		    || (strlen(argv[argc-1]) == 2 && argv[argc-1][1] != 'p')) {
+			fprintf(stderr, "Error: Invalid mode '%s'!\n", argv[argc-1]);
+			help();
+		}
 		switch (argv[argc-1][0]) {
+		case 'b': size = I2C_SMBUS_BYTE_DATA; break;
+		case 'w': size = I2C_SMBUS_WORD_DATA; break;
 		case 's': size = I2C_SMBUS_BLOCK_DATA; break;
 		case 'i': size = I2C_SMBUS_I2C_BLOCK_DATA; break;
 		default:
-			size = 0;
-			break;
+			fprintf(stderr, "Error: Invalid mode '%s'!\n", argv[argc-1]);
+			help();
 		}
+		pec = argv[argc-1][1] == 'p';
 		if (size == I2C_SMBUS_BLOCK_DATA || size == I2C_SMBUS_I2C_BLOCK_DATA) {
-			pec = argv[argc-1][1] == 'p';
 			if (pec && size == I2C_SMBUS_I2C_BLOCK_DATA) {
 				fprintf(stderr, "Error: PEC not supported for I2C block writes!\n");
 				help();
@@ -231,49 +250,48 @@ int main(int argc, char *argv[])
 				fprintf(stderr, "Error: Too many arguments!\n");
 				help();
 			}
-			for (len = 0; len + flags + 5 < argc; len++) {
-				value = strtol(argv[flags + len + 4], &end, 0);
-				if (*end || value < 0 || value > 0xff) {
-                                	fprintf(stderr, "Error: Block data value invalid!\n");
-                                	help();
-                        	}
-				block[len] = value;
-			}
-			goto dofile;
 		} else if (argc != flags + 6) {
 			fprintf(stderr, "Error: Too many arguments!\n");
 			help();
 		}
 	}
 
-	if (argc > flags + 4) {
-		if (!strcmp(argv[flags+4], "c")
-		 || !strcmp(argv[flags+4], "cp")) {
-			size = I2C_SMBUS_BYTE;
-			value = -1;
-			pec = argv[flags+4][1] == 'p';
-		} else {
-			size = I2C_SMBUS_BYTE_DATA;
-			value = strtol(argv[flags+4], &end, 0);
+	len = 0; /* Must always initialize len since it is passed to confirm() */
+
+	/* read values from command line */
+	switch (size) {
+	case I2C_SMBUS_BYTE_DATA:
+	case I2C_SMBUS_WORD_DATA:
+		value = strtol(argv[flags+4], &end, 0);
+		if (*end || value < 0) {
+			fprintf(stderr, "Error: Data value invalid!\n");
+			help();
+		}
+		if ((size == I2C_SMBUS_BYTE_DATA && value > 0xff)
+		    || (size == I2C_SMBUS_WORD_DATA && value > 0xffff)) {
+			fprintf(stderr, "Error: Data value out of range!\n");
+			help();
+		}
+		break;
+	case I2C_SMBUS_BLOCK_DATA:
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		for (len = 0; len + flags + 5 < argc; len++) {
+			value = strtol(argv[flags + len + 4], &end, 0);
 			if (*end || value < 0) {
 				fprintf(stderr, "Error: Data value invalid!\n");
 				help();
 			}
+			if (value > 0xff) {
+				fprintf(stderr, "Error: Data value out of range!\n");
+				help();
+			}
+			block[len] = value;
 		}
-	} else {
-		size = I2C_SMBUS_BYTE;
 		value = -1;
-	}
-
-	if (argc > flags + 5) {
-		switch (argv[flags+5][0]) {
-		case 'b': size = I2C_SMBUS_BYTE_DATA; break;
-		case 'w': size = I2C_SMBUS_WORD_DATA; break;
-		default:
-			fprintf(stderr, "Error: Invalid mode!\n");
-			help();
-		}
-		pec = argv[flags+5][1] == 'p';
+		break;
+	default:
+		value = -1;
+		break;
 	}
 
 	if (maskp) {
@@ -284,13 +302,6 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	if ((size == I2C_SMBUS_BYTE_DATA && value > 0xff)
-	 || (size == I2C_SMBUS_WORD_DATA && value > 0xffff)) {
-		fprintf(stderr, "Error: Data value out of range!\n");
-		help();
-	}
-
-dofile:
 	file = open_i2c_dev(i2cbus, filename, sizeof(filename), 0);
 	if (file < 0
 	 || check_funcs(file, size, pec)
-- 
1.7.0.4