1 files changed, 160 insertions, 134 deletions

diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c
index 05459bb7..0d9020ee 100644
--- a/util/nvmutil/nvmutil.c
+++ b/util/nvmutil/nvmutil.c
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: MIT */
-/* Copyright (c) 2022-2025 Leah Rowe <leah@libreboot.org> */
+/* Copyright (c) 2022-2026 Leah Rowe <leah@libreboot.org> */
 /* Copyright (c) 2023 Riku Viitanen <riku.viitanen@protonmail.com> */
 
 #include <sys/stat.h>
@@ -15,12 +15,19 @@
 #include <unistd.h>
 
 void cmd_setchecksum(void), cmd_brick(void), swap(int partnum), writeGbe(void),
-    cmd_dump(void), cmd_setmac(void), readGbe(void), checkdir(const char *path),
-    macf(int partnum), hexdump(int partnum), openFiles(const char *path),
-    cmd_copy(void), parseMacString(const char *strMac, uint16_t *mac),
-    cmd_swap(void);
+    cmd_dump(void), cmd_setmac(void), nvmalloc(void), readGbe(void),
+    checkdir(const char *path), macf(int partnum), hexdump(int partnum),
+    parseMacString(const char *strMac, uint16_t *mac), cmd_swap(void),
+    openFiles(const char *path), cmd_copy(void), writeGbe_part(int),
+    readGbe_part(int), usage(char*), set_io_flags(int, char **),
+    set_cmd(int, char **), setWord(int, int, uint16_t), check_bounds(int, int);
 int goodChecksum(int partnum);
 uint8_t hextonum(char chs), rhex(void);
+uint16_t word(int, int);
+
+#ifdef __OpenBSD__
+void block_unveil(void);
+#endif
 
 #define COMMAND argv[2]
 #define MAC_ADDRESS argv[3]
@@ -38,9 +45,10 @@ uint16_t mac[3] = {0, 0, 0};
 ssize_t nf;
 size_t partsize, gbe[2];
 uint8_t nvmPartChanged[2] = {0, 0}, do_read[2] = {1, 1};
-int flags, rfd, fd, part;
+int flags, rfd, fd, part, e = 1;
+struct stat st;
 
-const char *strMac = NULL, *strRMac = "xx:xx:xx:xx:xx:xx", *filename = NULL;
+const char *strMac = NULL, *strRMac = "xx:xx:xx:xx:xx:xx", *fname = NULL;
 
 typedef struct op {
 	char *str;
@@ -57,76 +65,49 @@ op_t op[] = {
 };
 void (*cmd)(void) = NULL;
 
-#define ERR() errno = errno ? errno : ECANCELED
-#define err_if(x) if (x) err(ERR(), "%s", filename)
-
-#define xopen(f,l,p) if ((f = open(l, p)) == -1) err(ERR(), "%s", l); \
-    if (fstat(f, &st) == -1) err(ERR(), "%s", l)
+#define SET_ERR(x) errno = errno ? errno : x
+#define err_if(x) if (x) err(SET_ERR(ECANCELED), "%s", fname)
 
-#define word(pos16, partnum) ((uint16_t *) gbe[partnum])[pos16]
-#define setWord(pos16, p, val16) if (word(pos16, p) != val16) \
-    nvmPartChanged[p] = 1 | (word(pos16, p) = val16)
+#define xopen(f,l,p) \
+	if ((f = open(l, p)) == -1) \
+	    err(SET_ERR(ECANCELED), "%s", l); \
+	if (fstat(f, &st) == -1) \
+	    err(SET_ERR(ECANCELED), "%s", l)
 
 int
 main(int argc, char *argv[])
 {
 #ifdef __OpenBSD__
 	err_if(pledge("stdio rpath wpath unveil", NULL) == -1);
+	err_if(unveil("/dev/urandom", "r") == -1);
 #endif
+	set_cmd(argc, argv);
 
-	if (argc < 2) {
+	fname = argv[1];
+	set_io_flags(argc, argv);
 #ifdef __OpenBSD__
-		err_if(pledge("stdio", NULL) == -1);
+	block_unveil();
 #endif
-		fprintf(stderr, "Modify Intel GbE NVM images e.g. set MAC\n");
-		fprintf(stderr, "USAGE:\n");
-		fprintf(stderr, " %s FILE dump\n", argv[0]);
-		fprintf(stderr, " %s FILE\n # same as setmac without arg\n",
-		    argv[0]);
-		fprintf(stderr, " %s FILE setmac [MAC]\n", argv[0]);
-		fprintf(stderr, " %s FILE swap\n", argv[0]);
-		fprintf(stderr, " %s FILE copy 0|1\n", argv[0]);
-		fprintf(stderr, " %s FILE brick 0|1\n", argv[0]);
-		fprintf(stderr, " %s FILE setchecksum 0|1\n", argv[0]);
-		err(errno = ECANCELED, "Too few arguments");
-	}
-
-	filename = argv[1];
-
-	flags = O_RDWR;
-
-	if (argc > 2) {
-		if (strcmp(COMMAND, "dump") == 0) {
-			flags = O_RDONLY;
+	openFiles(fname);
 #ifdef __OpenBSD__
-			err_if(pledge("stdio rpath unveil", NULL) == -1);
+	err_if(pledge("stdio", NULL) == -1);
 #endif
-		}
-	}
-
-	checkdir("/dev/urandom");
-	checkdir(filename);
 
-#ifdef __OpenBSD__
-	err_if(unveil("/dev/urandom", "r") == -1);
-
-	if (flags == O_RDONLY) {
-		err_if(unveil(filename, "r") == -1);
-		err_if(unveil(NULL, NULL) == -1);
-		err_if(pledge("stdio rpath", NULL) == -1);
-	} else {
-		err_if(unveil(filename, "rw") == -1);
-		err_if(unveil(NULL, NULL) == -1);
-		err_if(pledge("stdio rpath wpath", NULL) == -1);
-	}
-#endif
+	nvmalloc();
+	readGbe();
+	(*cmd)();
+	writeGbe();
 
-	openFiles(filename);
-#ifdef __OpenBSD__
-	err_if(pledge("stdio", NULL) == -1);
-#endif
+	err_if((errno != 0) && (cmd != cmd_dump));
+	return errno;
+}
 
-	if (argc > 2) {
+void
+set_cmd(int argc, char *argv[])
+{
+	if (argc < 2) {
+		usage(argv[0]);
+	} else if (argc > 2) {
 		for (int i = 0; (i < 6) && (cmd == NULL); i++) {
 			if (strcmp(COMMAND, op[i].str) != 0)
 				continue;
@@ -134,10 +115,10 @@ main(int argc, char *argv[])
 				cmd = op[i].cmd;
 				break;
 			}
-			err(errno = EINVAL, "Too few args on command '%s'",
+			err(SET_ERR(EINVAL), "Too few args on command '%s'",
 			    op[i].str);
 		}
-	} else {
+	} else { /* argc == 2 */
 		cmd = cmd_setmac;
 	}
 
@@ -153,20 +134,22 @@ main(int argc, char *argv[])
 		    || PARTN[1] ? EINVAL : errno)); /* only allow '0' or '1' */
 	}
 	err_if((errno = (cmd == NULL) ? EINVAL : errno));
+}
 
-	readGbe();
-	(*cmd)();
-	writeGbe();
-
-	err_if((errno != 0) && (cmd != cmd_dump));
-	return errno;
+void
+set_io_flags(int argc, char *argv[])
+{
+	flags = O_RDWR;
+	if (argc > 2)
+		if (strcmp(COMMAND, "dump") == 0)
+			flags = O_RDONLY;
 }
 
 void
 checkdir(const char *path)
 {
 	if (opendir(path) != NULL)
-		err(errno = EISDIR, "%s", path);
+		err(SET_ERR(EISDIR), "%s", path);
 	if (errno == ENOTDIR)
 		errno = 0;
 	err_if(errno);
@@ -175,8 +158,10 @@ checkdir(const char *path)
 void
 openFiles(const char *path)
 {
-	struct stat st;
+	checkdir("/dev/urandom");
+	checkdir(fname);
 
+	xopen(rfd, "/dev/urandom", O_RDONLY);
 	xopen(fd, path, flags);
 
 	switch(st.st_size) {
@@ -186,49 +171,49 @@ openFiles(const char *path)
 		partsize = st.st_size >> 1;
 		break;
 	default:
-		err(errno = ECANCELED, "Invalid file size (not 8/16/128KiB)");
+		err(SET_ERR(ECANCELED), "Invalid file size (not 8/16/128KiB)");
 		break;
 	}
-
-	xopen(rfd, "/dev/urandom", O_RDONLY);
 }
 
 void
-readGbe(void)
+nvmalloc(void)
 {
+	/* same operations need the full block, others only 128 bytes */
+	nf = NVM_SIZE;
 	if ((cmd == cmd_swap) || (cmd == cmd_copy))
 		nf = SIZE_4KB;
-	else
-		nf = NVM_SIZE;
 
+	/* only read the part specified, for copy/setchecksum/brick */
 	if ((cmd == cmd_copy) || (cmd == cmd_setchecksum) || (cmd == cmd_brick))
 		do_read[part ^ 1] = 0;
 
+	/* only allocate one block if only one part being read */
 	char *buf = malloc(nf << (do_read[0] & do_read[1]));
 	if (buf == NULL)
 		err(errno, NULL);
 
 	gbe[0] = (size_t) buf;
-	gbe[1] = gbe[0] + (nf * (do_read[0] & do_read[1]));
 
-	ssize_t tnr = 0;
-
-	for (int p = 0; p < 2; p++) {
-		if (!do_read[p])
-			continue;
-
-		ssize_t nr = pread(fd, (uint8_t *) gbe[p], nf, p * partsize);
-		err_if(nr == -1);
-		if (nr != nf)
-			err(errno == ECANCELED,
-			    "%ld bytes read from '%s', expected %ld bytes\n",
-			    nr, filename, nf);
+	/* speedhack: for cmd copy, both pointers are set the same */
+	gbe[1] = gbe[0] + (nf * (do_read[0] & do_read[1]));
+}
 
-		tnr += nr;
-		swap(p); /* handle big-endian host CPU */
-	}
+void
+readGbe(void)
+{
+	for (int p = 0; p < 2; p++)
+		if (do_read[p])
+			readGbe_part(p);
+}
 
-	printf("%ld bytes read from file '%s'\n", tnr, filename);
+void
+readGbe_part(int p)
+{
+	if (pread(fd, (uint8_t *) gbe[p], nf, p * partsize) != nf)
+		err(SET_ERR(ECANCELED),
+		    "Can't read %ld b from '%s' p%d", nf, fname, p);
+	swap(p); /* handle big-endian host CPU */
 }
 
 void
@@ -262,12 +247,12 @@ parseMacString(const char *strMac, uint16_t *mac)
 {
 	uint64_t total = 0;
 	if (strnlen(strMac, 20) != 17)
-		err(errno = EINVAL, "Invalid MAC address string length");
+		err(SET_ERR(EINVAL), "Invalid MAC address string length");
 
 	for (uint8_t h, i = 0; i < 16; i += 3) {
 		if (i != 15)
 			if (strMac[i + 2] != ':')
-				err(errno = EINVAL,
+				err(SET_ERR(EINVAL),
 				    "Invalid MAC address separator '%c'",
 				    strMac[i + 2]);
 
@@ -275,7 +260,7 @@ parseMacString(const char *strMac, uint16_t *mac)
 
 		for (int nib = 0; nib < 2; nib++, total += h) {
 			if ((h = hextonum(strMac[i + nib])) > 15)
-				err(errno = EINVAL, "Invalid character '%c'",
+				err(SET_ERR(EINVAL), "Invalid character '%c'",
 				    strMac[i + nib]);
 
 			/* If random, ensure that local/unicast bits are set */
@@ -291,9 +276,9 @@ parseMacString(const char *strMac, uint16_t *mac)
 	}
 
 	if (total == 0)
-		err(errno = EINVAL, "Invalid MAC (all-zero MAC address)");
+		err(SET_ERR(EINVAL), "Invalid MAC (all-zero MAC address)");
 	if (mac[0] & 1)
-		err(errno = EINVAL, "Invalid MAC (multicast bit set)");
+		err(SET_ERR(EINVAL), "Invalid MAC (multicast bit set)");
 }
 
 uint8_t
@@ -307,8 +292,7 @@ hextonum(char ch)
 		return ch - 'a' + 10;
 	else if ((ch == '?') || (ch == 'x') || (ch == 'X'))
 		return rhex(); /* random hex value */
-	else
-		return 16; /* error: invalid character */
+	return 16; /* error: invalid character */
 }
 
 uint8_t
@@ -415,58 +399,100 @@ goodChecksum(int partnum)
 		return 1;
 
 	fprintf(stderr, "WARNING: BAD checksum in part %d\n", partnum);
-	errno = ECANCELED;
+	SET_ERR(ECANCELED);
 	return 0;
 }
 
-void
-writeGbe(void)
+uint16_t
+word(int pos16, int p)
 {
-	ssize_t tnw = 0;
-
-	for (int p = 0; p < 2; p++) {
-		if ((!nvmPartChanged[p]) || (flags == O_RDONLY))
-			continue;
-
-		swap(p); /* swap bytes on big-endian host CPUs */
-		ssize_t nw = pwrite(fd, (uint8_t *) gbe[p], nf, p * partsize);
-		err_if(nw == -1);
-		if (nw != nf)
-			err(errno == ECANCELED,
-			    "%ld bytes written to '%s', expected %ld bytes\n",
-			    nw, filename, nf);
+	check_bounds(pos16, p);
+	return ((uint16_t *) gbe[p])[pos16];
+}
 
-		tnw += nf;
+void
+setWord(int pos16, int p, uint16_t val16)
+{
+	check_bounds(pos16, p);
+	if (((uint16_t *) gbe[p])[pos16] != val16) {
+		nvmPartChanged[p] = 1;
+		((uint16_t *) gbe[p])[pos16] = val16;
 	}
+}
 
-	if ((flags != O_RDONLY) && (cmd != cmd_dump)) {
-		if (nvmPartChanged[0] || nvmPartChanged[1])
-			printf("The following nvm words were written:\n");
-		cmd_dump();
-	}
+void
+check_bounds(int c, int p)
+{
+	if ((p != 0) && (p != 1))
+		err(SET_ERR(EINVAL), "check_bounds: invalid partnum %d", p);
+	if ((c < 0) || (c > ((nf >> 1) - 1)))
+		err(SET_ERR(EINVAL), "check_bounds: out of bounds %d", c);
+}
 
-	if ((!tnw) && (flags != O_RDONLY) && (!errno))
-		fprintf(stderr, "No changes needed on file '%s'\n", filename);
-	else if (tnw)
-		printf("%ld bytes written to file '%s'\n", tnw, filename);
+void
+writeGbe(void)
+{
+	for (int p = 0; p < 2; p++)
+		if ((nvmPartChanged[p]) && (flags != O_RDONLY))
+			writeGbe_part(p);
+	err_if(close(fd) == -1);
+}
 
-	if (tnw)
-		errno = 0;
+void
+writeGbe_part(int p)
+{
+	swap(p); /* swap bytes on big-endian host CPUs */
+	if(pwrite(fd, (uint8_t *) gbe[p], nf, p * partsize) != nf)
+		err(SET_ERR(ECANCELED),
+		    "Can't write %ld b to '%s' p%d", nf, fname, p);
 
-	err_if(close(fd) == -1);
 }
 
 void
 swap(int partnum)
 {
-	size_t w, x;
 	uint8_t *n = (uint8_t *) gbe[partnum];
-	int e = 1;
 
-	for (w = NVM_SIZE * ((uint8_t *) &e)[0], x = 1; w < NVM_SIZE;
-	    w += 2, x += 2) {
+	for (size_t w = NVM_SIZE * ((uint8_t *) &e)[0], x = 1;
+	    w < NVM_SIZE; w += 2, x += 2) {
 		n[w] ^= n[x];
 		n[x] ^= n[w];
 		n[w] ^= n[x];
 	}
 }
+
+#ifdef __OpenBSD__
+void
+block_unveil(void)
+{
+	if (flags == O_RDONLY) {
+		err_if(unveil(fname, "r") == -1);
+		err_if(unveil(NULL, NULL) == -1);
+		err_if(pledge("stdio rpath", NULL) == -1);
+	} else {
+		err_if(unveil(fname, "rw") == -1);
+		err_if(unveil(NULL, NULL) == -1);
+		err_if(pledge("stdio rpath wpath", NULL) == -1);
+	}
+}
+#endif
+
+void
+usage(char *util)
+{
+#ifdef __OpenBSD__
+	err_if(pledge("stdio", NULL) == -1);
+#endif
+	fprintf(stderr,
+	    "Modify Intel GbE NVM images e.g. set MAC\n"
+	    "USAGE:\n"
+	    "%s FILE dump\n"
+	    " %s FILE\n # same as setmac without arg\n"
+	    " %s FILE setmac [MAC]\n"
+	    " %s FILE swap\n"
+	    " %s FILE copy 0|1\n"
+	    " %s FILE brick 0|1\n"
+	    " %s FILE setchecksum 0|1\n",
+	    util, util, util, util, util, util, util);
+	err(SET_ERR(ECANCELED), "Too few arguments");
+}