ethtool: add support for block writing of EEPROMs

EEPROM write only supports byte writing. Add support for writing an arbitrary number of bytes at an arbitrary offset.

Signed-off-by Mandeep Singh Baines <[email protected]>

---
 ethtool.8 |   12 ++++++++----
 ethtool.c |   58 ++++++++++++++++++++++++++++++++++++++++++++--------------
 2 files changed, 52 insertions(+), 18 deletions(-)

ethtool.8 +8 -4

index cc6a46e..90d160a 100644
@@ -144,6 +144,8 @@ ethtool \- Display or change ethernet card settings
 .IR N ]
 .RB [ offset
 .IR N ]
+.RB [ length
+.IR N ]
 .RB [ value
 .IR N ]
 

@@ -265,10 +267,12 @@ length and offset parameters allow dumping certain portions of the EEPROM.
 Default is to dump the entire EEPROM.
 .TP
 .B \-E \-\-change\-eeprom
-Changes EEPROM byte for the specified ethernet device.  offset and value
-specify which byte and it's new value.  Because of the persistent nature
-of writing to the EEPROM, a device-specific magic key must be specified
-to prevent the accidental writing to the EEPROM.
+If value is specified, changes EEPROM byte for the specified ethernet device.
+offset and value specify which byte and it's new value. If value is not
+specified, stdin is read and written to the EEPROM. The length and offset
+parameters allow writing to certain portions of the EEPROM.
+Because of the persistent nature of writing to the EEPROM, a device-specific
+magic key must be specified to prevent the accidental writing to the EEPROM.
 .TP
 .B \-k \-\-show\-offload
 Queries the specified ethernet device for offload information.

ethtool.c +44 -15

index a668b49..3fce21c 100644
@@ -163,6 +163,7 @@ static struct option {
    { "-E", "--change-eeprom", MODE_SEEPROM, "Change bytes in device EEPROM",
               "               [ magic N ]\n"
               "               [ offset N ]\n"
+               "               [ length N ]\n"
               "               [ value N ]\n" },
    { "-r", "--negotiate", MODE_NWAY_RST, "Restart N-WAY negotation" },
    { "-p", "--identify", MODE_PHYS_ID, "Show visible port identification (e.g. blinking)",

@@ -264,8 +265,9 @@ static int geeprom_offset = 0;
 static int geeprom_length = -1;
 static int seeprom_changed = 0;
 static int seeprom_magic = 0;
-static int seeprom_offset = -1;
-static int seeprom_value = 0;
+static int seeprom_length = -1;
+static int seeprom_offset = 0;
+static int seeprom_value = EOF;
 static enum {
       ONLINE=0,
       OFFLINE,

@@ -300,6 +302,7 @@ static struct cmdline_info cmdline_geeprom[] = {
 static struct cmdline_info cmdline_seeprom[] = {
       { "magic", CMDL_INT, &seeprom_magic, NULL },
       { "offset", CMDL_INT, &seeprom_offset, NULL },
+       { "length", CMDL_INT, &seeprom_length, NULL },
       { "value", CMDL_INT, &seeprom_value, NULL },
 };
 

@@ -1920,22 +1923,49 @@ static int do_geeprom(int fd, struct ifreq *ifr)
 static int do_seeprom(int fd, struct ifreq *ifr)
 {
       int err;
-       struct {
-               struct ethtool_eeprom eeprom;
-               u8 data;
-       } edata;
-
-       edata.eeprom.cmd = ETHTOOL_SEEPROM;
-       edata.eeprom.len = 1;
-       edata.eeprom.offset = seeprom_offset;
-       edata.eeprom.magic = seeprom_magic;
-       edata.data = seeprom_value;
-       ifr->ifr_data = (caddr_t)&edata.eeprom;
+       struct ethtool_drvinfo drvinfo;
+       struct ethtool_eeprom *eeprom;
+
+       drvinfo.cmd = ETHTOOL_GDRVINFO;
+       ifr->ifr_data = (caddr_t)&drvinfo;
+       err = ioctl(fd, SIOCETHTOOL, ifr);
+       if (err < 0) {
+               perror("Cannot get driver information");
+               return 74;
+       }
+
+       if (seeprom_value != EOF)
+               seeprom_length = 1;
+
+       if (seeprom_length <= 0)
+               seeprom_length = drvinfo.eedump_len;
+
+       if (drvinfo.eedump_len < seeprom_offset + seeprom_length)
+               seeprom_length = drvinfo.eedump_len - seeprom_offset;
+
+       eeprom = calloc(1, sizeof(*eeprom)+seeprom_length);
+       if (!eeprom) {
+               perror("Cannot allocate memory for EEPROM data");
+               return 75;
+       }
+
+       eeprom->cmd = ETHTOOL_SEEPROM;
+       eeprom->len = seeprom_length;
+       eeprom->offset = seeprom_offset;
+       eeprom->magic = seeprom_magic;
+       eeprom->data[0] = seeprom_value;
+
+       /* Multi-byte write: read input from stdin */
+       if (seeprom_value == EOF)
+               eeprom->len = fread(eeprom->data, 1, eeprom->len, stdin);
+
+       ifr->ifr_data = (caddr_t)eeprom;
       err = ioctl(fd, SIOCETHTOOL, ifr);
       if (err < 0) {
               perror("Cannot set EEPROM data");
-               return 87;
+               err = 87;
       }
+       free(eeprom);
 
       return err;
 }
--

1.5.2.5