canoeboot
/
cbmk
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

util/nvmutil: General code cleanup 

A lot of size-coding was performed in prior audits, to
make the sloccount lower on nvmutil, but this resulted in
code that wasn't very human readable.

I've reversed some of it and added comments, for clarity.

Signed-off-by: Leah Rowe <leah@libreboot.org>
20250107_branch
Leah Rowe 2025-01-24 11:33:30 +00:00
parent 232f6b8610
commit fe55e33254
1 changed files with 65 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

92
util/nvmutil/nvmutil.c
View File

@ -28,12 +28,13 @@ uint8_t hextonum(char chs), rhex(void);
uint16_t buf16[SIZE_4KB], mac[3] = {0, 0, 0}; uint16_t buf16[SIZE_4KB], mac[3] = {0, 0, 0};
uint8_t *buf = (uint8_t *) &buf16; uint8_t *buf = (uint8_t *) &buf16;
size_t nf = 128, gbe[2]; size_t nf, gbe[2];
uint8_t nvmPartChanged[2] = {0, 0}, skipread[2] = {0, 0}; uint8_t nvmPartChanged[2] = {0, 0}, skipread[2] = {0, 0};
int e = 1, flags = O_RDWR, rfd, fd, part, gbeFileChanged = 0; int e = 1, flags, rfd, fd, part, gbeFileChanged = 0;
const char *strMac = NULL, *strRMac = "??:??:??:??:??:??", *filename = NULL; const char *strMac = NULL, *strRMac = "??:??:??:??:??:??", *filename = NULL;
/* available commands, set a pointer based on user command */
typedef struct op { typedef struct op {
char *str; char *str;
void (*cmd)(void); void (*cmd)(void);
@ -49,13 +50,16 @@ op_t op[] = {
}; };
void (*cmd)(void) = NULL; void (*cmd)(void) = NULL;
/* wrappers for BSD-style err() function (error handling) */
#define ERR() errno = errno ? errno : ECANCELED #define ERR() errno = errno ? errno : ECANCELED
#define err_if(x) if (x) err(ERR(), "%s", filename) #define err_if(x) if (x) err(ERR(), "%s", filename)
/* Macro for opening a file with errors properly handled */
#define xopen(f,l,p) if (opendir(l) != NULL) err(errno = EISDIR, "%s", l); \ #define xopen(f,l,p) if (opendir(l) != NULL) err(errno = EISDIR, "%s", l); \
if ((f = open(l, p)) == -1) err(ERR(), "%s", l); \ if ((f = open(l, p)) == -1) err(ERR(), "%s", l); \
if (fstat(f, &st) == -1) err(ERR(), "%s", l) if (fstat(f, &st) == -1) err(ERR(), "%s", l)
/* Macros for reading/writing the GbE file in memory */
#define word(pos16, partnum) buf16[pos16 + (partnum << 11)] #define word(pos16, partnum) buf16[pos16 + (partnum << 11)]
#define setWord(pos16, p, val16) if ((gbeFileChanged = 1) && \ #define setWord(pos16, p, val16) if ((gbeFileChanged = 1) && \
word(pos16, p) != val16) nvmPartChanged[p] = 1 | (word(pos16, p) = val16) word(pos16, p) != val16) nvmPartChanged[p] = 1 | (word(pos16, p) = val16)
@ -63,7 +67,7 @@ void (*cmd)(void) = NULL;
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
if (argc < 3) { if (argc < 3) { /* TODO: manpage! */
fprintf(stderr, "Modify Intel GbE NVM images e.g. set MAC\n"); fprintf(stderr, "Modify Intel GbE NVM images e.g. set MAC\n");
fprintf(stderr, "USAGE:\n"); fprintf(stderr, "USAGE:\n");
fprintf(stderr, " %s FILE dump\n", argv[0]); fprintf(stderr, " %s FILE dump\n", argv[0]);
@ -74,43 +78,54 @@ main(int argc, char *argv[])
fprintf(stderr, " %s FILE setchecksum 0|1\n", argv[0]); fprintf(stderr, " %s FILE setchecksum 0|1\n", argv[0]);
err(errno = ECANCELED, "Too few arguments"); err(errno = ECANCELED, "Too few arguments");
} }
flags = (strcmp(COMMAND, "dump") == 0) ? O_RDONLY : flags; if (strcmp(COMMAND, "dump") == 0)
flags = O_RDONLY; /* write not needed for dump cmd */
else
flags = O_RDWR;
filename = argv[1]; filename = argv[1];
#ifdef __OpenBSD__ #ifdef __OpenBSD__
/* OpenBSD sandboxing: https://man.openbsd.org/pledge.2 */
/* Also: https://man.openbsd.org/unveil.2 */
err_if(unveil("/dev/urandom", "r") == -1); err_if(unveil("/dev/urandom", "r") == -1);
if (flags == O_RDONLY) { if (flags == O_RDONLY) { /* write not needed for dump command */
err_if(unveil(filename, "r") == -1); err_if(unveil(filename, "r") == -1);
err_if(pledge("stdio rpath", NULL) == -1); err_if(pledge("stdio rpath", NULL) == -1);
} else { } else { /* not dump command, so pledge read-write instead */
err_if(unveil(filename, "rw") == -1); err_if(unveil(filename, "rw") == -1);
err_if(pledge("stdio rpath wpath", NULL) == -1); err_if(pledge("stdio rpath wpath", NULL) == -1);
} }
#endif #endif
/* open files, but don't read yet; do pledge after, *then* read */
openFiles(filename); openFiles(filename);
#ifdef __OpenBSD__ #ifdef __OpenBSD__
/* OpenBSD sandboxing: https://man.openbsd.org/pledge.2 */
err_if(pledge("stdio", NULL) == -1); err_if(pledge("stdio", NULL) == -1);
#endif #endif
for (int i = 0; i < 6; i++) for (int i = 0; i < 6; i++) /* detect user-supplied command */
if (strcmp(COMMAND, op[i].str) == 0) if (strcmp(COMMAND, op[i].str) == 0)
if ((cmd = argc >= op[i].args ? op[i].cmd : NULL)) if ((cmd = argc >= op[i].args ? op[i].cmd : NULL))
break; break; /* function ptr set, as per user cmd */
if (cmd == cmd_setmac) if (cmd == cmd_setmac) { /* user wishes to set the MAC address */
strMac = (argc > 3) ? MAC_ADDRESS : strRMac; strMac = strRMac; /* random mac */
else if ((cmd != NULL) && (argc > 3)) if (argc > 3) /* user-supplied mac (can be random) */
strMac = MAC_ADDRESS;
} else if ((cmd != NULL) && (argc > 3)) { /* user-supplied partnum */
err_if((errno = (!((part = PARTN[0] - '0') == 0 || part == 1)) err_if((errno = (!((part = PARTN[0] - '0') == 0 || part == 1))
|| PARTN[1] ? EINVAL : errno)); || PARTN[1] ? EINVAL : errno)); /* only allow '0' or '1' */
err_if((errno = (cmd == NULL) ? EINVAL : errno)); }
err_if((errno = (cmd == NULL) ? EINVAL : errno)); /* bad user arg */
readGbe(); readGbe(); /* read gbe file into memory */
(*cmd)(); (*cmd)(); /* operate on gbe file in memory, as per user command */
if ((gbeFileChanged) && (flags != O_RDONLY) && (cmd != writeGbe)) if ((gbeFileChanged) && (flags != O_RDONLY) && (cmd != writeGbe))
writeGbe(); writeGbe(); /* not called for swap cmd; swap calls writeGbe */
err_if((errno != 0) && (cmd != cmd_dump)); err_if((errno != 0) && (cmd != cmd_dump)); /* don't err on dump */
return errno; return errno; /* errno can be set by the dump command */
} }
/* open gbe file and /dev/urandom, setting permissions */
void void
openFiles(const char *path) openFiles(const char *path)
{ {
@ -119,13 +134,18 @@ openFiles(const char *path)
if ((st.st_size != (SIZE_4KB << 1))) if ((st.st_size != (SIZE_4KB << 1)))
err(errno = ECANCELED, "File `%s` not 8KiB", path); err(errno = ECANCELED, "File `%s` not 8KiB", path);
xopen(rfd, "/dev/urandom", O_RDONLY); xopen(rfd, "/dev/urandom", O_RDONLY);
errno = errno != ENOTDIR ? errno : 0; if (errno == ENOTDIR)
errno = 0;
} }
/* read gbe file into memory buffer */
void void
readGbe(void) readGbe(void)
{ {
nf = ((cmd == writeGbe) || (cmd == cmd_copy)) ? SIZE_4KB : nf; if ((cmd == writeGbe) || (cmd == cmd_copy))
nf = SIZE_4KB;
else
nf = 128;
skipread[part ^ 1] = (cmd == cmd_copy) | (cmd == cmd_setchecksum) skipread[part ^ 1] = (cmd == cmd_copy) | (cmd == cmd_setchecksum)
| (cmd == cmd_brick); | (cmd == cmd_brick);
gbe[1] = (gbe[0] = (size_t) buf) + SIZE_4KB; gbe[1] = (gbe[0] = (size_t) buf) + SIZE_4KB;
@ -133,10 +153,11 @@ readGbe(void)
if (skipread[p]) if (skipread[p])
continue; continue;
err_if(pread(fd, (uint8_t *) gbe[p], nf, p << 12) == -1); err_if(pread(fd, (uint8_t *) gbe[p], nf, p << 12) == -1);
swap(p); swap(p); /* handle big-endian host CPU */
} }
} }
/* set MAC address and checksum on nvm part */
void void
cmd_setmac(void) cmd_setmac(void)
{ {
@ -151,6 +172,7 @@ cmd_setmac(void)
} }
} }
/* parse MAC string, write to char buffer */
int int
macAddress(const char *strMac, uint16_t *mac) macAddress(const char *strMac, uint16_t *mac)
{ {
@ -174,6 +196,7 @@ macAddress(const char *strMac, uint16_t *mac)
return ((total == 0) | (mac[0] & 1)); /* multicast/all-zero banned */ return ((total == 0) | (mac[0] & 1)); /* multicast/all-zero banned */
} }
/* convert hex char to char value (0-15) */
uint8_t uint8_t
hextonum(char ch) hextonum(char ch)
{ {
@ -183,9 +206,10 @@ hextonum(char ch)
return ch - 'A' + 10; return ch - 'A' + 10;
else if ((ch >= 'a') && (ch <= 'f')) else if ((ch >= 'a') && (ch <= 'f'))
return ch - 'a' + 10; return ch - 'a' + 10;
return (ch == '?') ? rhex() : 16; return (ch == '?') ? rhex() : 16; /* 16 for error (invalid char) */
} }
/* random number generator */
uint8_t uint8_t
rhex(void) rhex(void)
{ {
@ -195,6 +219,7 @@ rhex(void)
return rnum[n--] & 0xf; return rnum[n--] & 0xf;
} }
/* print mac address and hexdump of parts */
void void
cmd_dump(void) cmd_dump(void)
{ {
@ -203,20 +228,26 @@ cmd_dump(void)
++numInvalid; ++numInvalid;
printf("MAC (part %d): ", partnum); printf("MAC (part %d): ", partnum);
macf(partnum), hexdump(partnum); macf(partnum), hexdump(partnum);
errno = ((numInvalid < 2) && (partnum)) ? 0 : errno; if ((numInvalid < 2) && (partnum))
errno = 0;
} }
} }
/* print mac address of part */
void void
macf(int partnum) macf(int partnum)
{ {
for (int c = 0; c < 3; c++) { for (int c = 0; c < 3; c++) {
uint16_t val16 = word(c, partnum); uint16_t val16 = word(c, partnum);
printf("%02x:%02x", val16 & 0xff, val16 >> 8); printf("%02x:%02x", val16 & 0xff, val16 >> 8);
printf(c == 2 ? "\n" : ":"); if (c == 2)
printf("\n");
else
printf(":");
} }
} }
/* print hexdump of nvm part */
void void
hexdump(int partnum) hexdump(int partnum)
{ {
@ -227,10 +258,12 @@ hexdump(int partnum)
if (c == 4) if (c == 4)
printf(" "); printf(" ");
printf(" %02x %02x", val16 & 0xff, val16 >> 8); printf(" %02x %02x", val16 & 0xff, val16 >> 8);
} printf("\n"); }
printf("\n");
} }
} }
/* correct the checksum on part */
void void
cmd_setchecksum(void) cmd_setchecksum(void)
{ {
@ -240,6 +273,7 @@ cmd_setchecksum(void)
setWord(0x3F, part, NVM_CHECKSUM - val16); setWord(0x3F, part, NVM_CHECKSUM - val16);
} }
/* intentionally set wrong checksum on part */
void void
cmd_brick(void) cmd_brick(void)
{ {
@ -247,6 +281,7 @@ cmd_brick(void)
setWord(0x3F, part, ((word(0x3F, part)) ^ 0xFF)); setWord(0x3F, part, ((word(0x3F, part)) ^ 0xFF));
} }
/* overwrite the contents of one part with the other */
void void
cmd_copy(void) cmd_copy(void)
{ {
@ -254,6 +289,7 @@ cmd_copy(void)
gbe[part ^ 1] = gbe[part]; /* speedhack: copy ptr, not words */ gbe[part ^ 1] = gbe[part]; /* speedhack: copy ptr, not words */
} }
/* verify nvme part checksum (return 1 if valid) */
int int
goodChecksum(int partnum) goodChecksum(int partnum)
{ {
@ -266,6 +302,7 @@ goodChecksum(int partnum)
return (errno = ECANCELED) & 0; return (errno = ECANCELED) & 0;
} }
/* write the nvm parts back to the file */
void void
writeGbe(void) writeGbe(void)
{ {
@ -273,13 +310,14 @@ writeGbe(void)
for (int p = 0, x = (cmd == writeGbe) ? 1 : 0; p < 2; p++) { for (int p = 0, x = (cmd == writeGbe) ? 1 : 0; p < 2; p++) {
if ((!nvmPartChanged[p]) && (cmd != writeGbe)) if ((!nvmPartChanged[p]) && (cmd != writeGbe))
continue; continue;
swap(p^x); swap(p ^ x);
err_if(pwrite(fd, (uint8_t *) gbe[p^x], nf, p << 12) == -1); err_if(pwrite(fd, (uint8_t *) gbe[p ^ x], nf, p << 12) == -1);
} }
errno = 0; errno = 0;
err_if(close(fd) == -1); err_if(close(fd) == -1);
} }
/* swap byte order on big-endian CPUs. swap skipped on little endian */
void void
swap(int partnum) swap(int partnum)
{ {