virsysinfo: Parse OEM strings

Setting OEM strings for a domain was introduced in
v4.1.0-rc1~315. However, any application that wanted to use them
(e.g. to point to an URL where a config file is stored) had to
'dmidecode -u --oem-string N' (where N is index of the string).
Well, we can expose them under our <sysinfo/> XML and if the
domain is running Libvirt inside it can be obtained using
virConnectGetSysinfo() API.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
This commit is contained in:
Michal Privoznik 2020-06-02 10:15:38 +02:00
parent 994e56ba42
commit b44898dd31
4 changed files with 138 additions and 5 deletions

View File

@ -915,6 +915,103 @@ virSysinfoParseX86Chassis(const char *base,
}
static int
virSysinfoDMIDecodeOEMString(size_t i,
char **str)
{
g_autofree char *err = NULL;
g_autoptr(virCommand) cmd = virCommandNewArgList(DMIDECODE, "--dump",
"--oem-string", NULL);
virCommandAddArgFormat(cmd, "%zu", i);
virCommandSetOutputBuffer(cmd, str);
virCommandSetErrorBuffer(cmd, &err);
if (virCommandRun(cmd, NULL) < 0)
return -1;
/* Unfortunately, dmidecode returns 0 even if OEM String index is out
* of bounds, but it prints an error message in that case. Check stderr
* and return success/failure accordingly. */
if (err && *err != '\0')
return -1;
return 0;
}
static int
virSysinfoParseOEMStrings(const char *base,
virSysinfoOEMStringsDefPtr *stringsRet)
{
virSysinfoOEMStringsDefPtr strings = NULL;
size_t i = 1;
int ret = -1;
const char *cur;
if (!(cur = strstr(base, "OEM Strings")))
return 0;
if (VIR_ALLOC(strings) < 0)
return -1;
while ((cur = strstr(cur, "String "))) {
char *eol;
cur += 7;
if (!(eol = strchr(cur, '\n'))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Malformed output of dmidecode"));
goto cleanup;
}
while (g_ascii_isdigit(*cur))
cur++;
if (*cur != ':') {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Malformed output of dmidecode"));
goto cleanup;
}
cur += 2;
virSkipSpacesBackwards(cur, &eol);
if (!eol)
continue;
if (VIR_EXPAND_N(strings->values, strings->nvalues, 1) < 0)
goto cleanup;
/* If OEM String contains newline, dmidecode escapes it as a dot.
* If this is the case then run dmidecode again to get raw string.
* Unfortunately, we can't dinstinguish betwen dot an new line at
* this level. */
if (memchr(cur, '.', eol - cur)) {
char *str;
if (virSysinfoDMIDecodeOEMString(i, &str) < 0)
goto cleanup;
strings->values[strings->nvalues - 1] = g_steal_pointer(&str);
} else {
strings->values[strings->nvalues - 1] = g_strndup(cur, eol - cur);
}
i++;
cur = eol;
}
*stringsRet = g_steal_pointer(&strings);
ret = 0;
cleanup:
virSysinfoOEMStringsDefFree(strings);
return ret;
}
static int
virSysinfoParseX86Processor(const char *base, virSysinfoDefPtr ret)
{
@ -1119,7 +1216,7 @@ virSysinfoReadDMI(void)
g_autofree char *outbuf = NULL;
g_autoptr(virCommand) cmd = NULL;
cmd = virCommandNewArgList(DMIDECODE, "-q", "-t", "0,1,2,3,4,17", NULL);
cmd = virCommandNewArgList(DMIDECODE, "-q", "-t", "0,1,2,3,4,11,17", NULL);
virCommandSetOutputBuffer(cmd, &outbuf);
if (virCommandRun(cmd, NULL) < 0)
return NULL;
@ -1141,6 +1238,9 @@ virSysinfoReadDMI(void)
if (virSysinfoParseX86Chassis(outbuf, &ret->chassis) < 0)
return NULL;
if (virSysinfoParseOEMStrings(outbuf, &ret->oemStrings) < 0)
return NULL;
ret->nprocessor = 0;
ret->processor = NULL;
if (virSysinfoParseX86Processor(outbuf, ret) < 0)

View File

@ -81,3 +81,9 @@ Memory Device
Serial Number: 29057112
Asset Tag: 0839
Part Number: IMSH2GS13A1F1C-10F
OEM Strings
String 1: Hello
String 2: World
String 3: Ha ha ha try parsing\n. String 3: this correctly. String 4:then
String 4: This is, more tricky value=escaped

View File

@ -50,4 +50,12 @@
<entry name='serial_number'>29057112</entry>
<entry name='part_number'>IMSH2GS13A1F1C-10F</entry>
</memory_device>
<oemStrings>
<entry>Hello</entry>
<entry>World</entry>
<entry>Ha ha ha try parsing\n
String 3: this correctly
String 4:then</entry>
<entry>This is, more tricky value=escaped</entry>
</oemStrings>
</sysinfo>

View File

@ -56,10 +56,29 @@ testDMIDecodeDryRun(const char *const*args G_GNUC_UNUSED,
{
const char *sysinfo = opaque;
if (virFileReadAll(sysinfo, 10 * 1024 * 1024, output) < 0) {
*error = g_strdup(virGetLastErrorMessage());
*status = EXIT_FAILURE;
return;
if (STREQ_NULLABLE(args[1], "--dump") &&
STREQ_NULLABLE(args[2], "--oem-string")) {
if (!args[3]) {
*error = g_strdup("dmidecode: option '--oem-string' requires an argument");
*status = EXIT_FAILURE;
return;
}
if (STREQ(args[3], "3")) {
*output = g_strdup("Ha ha ha try parsing\\n\n"
" String 3: this correctly\n"
" String 4:then");
} else {
*error = g_strdup_printf("No OEM string number %s", args[3]);
*status = EXIT_FAILURE;
return;
}
} else {
if (virFileReadAll(sysinfo, 10 * 1024 * 1024, output) < 0) {
*error = g_strdup(virGetLastErrorMessage());
*status = EXIT_FAILURE;
return;
}
}
*error = g_strdup("");