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liblog: allow event tags to include some punctuations

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event_log_tag parser complains about a period (.) in the name,
we would consider such an enhancement to the tag names possible.
I expect we would want to be able to support alphanumerics,
underscore (_), period (.), minus (-), at (@) and comma (,) for
starters as they are present in the other text log buffer tags.

We introduce a local endOfTag function that is used during parsing and
during android_lookupEventTagNum for submitting new tags.  This
function caused us to enforce const char more closely.  By filtering
in both places we resolve an issue that could have plagued us if
garbage requests were made.

Test: gTest liblog-unit-tests, logd-unit-tests & logcat-unit-tests
Bug: 31456426
Change-Id: I596b8706e843719ddac07ec40e1cd2875c214bed
This commit is contained in:
Mark Salyzyn 2017-04-12 15:11:24 -07:00
parent 5768d3d976
commit 01bdb04be6
2 changed files with 32 additions and 23 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

53
liblog/event_tag_map.cpp
View file

@ -229,9 +229,16 @@ int EventTagMap::find(MapString&& tag) const {
return it->second;
}
// The position after the end of a valid section of the tag string,
// caller makes sure delimited appropriately.
static const char* endOfTag(const char* cp) {
while (*cp && (isalnum(*cp) || strchr("_.-@,", *cp))) ++cp;
return cp;
}
// Scan one tag line.
//
// "*pData" should be pointing to the first digit in the tag number. On
// "pData" should be pointing to the first digit in the tag number. On
// successful return, it will be pointing to the last character in the
// tag line (i.e. the character before the start of the next line).
//
@ -241,10 +248,11 @@ int EventTagMap::find(MapString&& tag) const {
// data and it will outlive the call.
//
// Returns 0 on success, nonzero on failure.
static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
char* cp;
unsigned long val = strtoul(*pData, &cp, 10);
if (cp == *pData) {
static int scanTagLine(EventTagMap* map, const char*& pData, int lineNum) {
char* ep;
unsigned long val = strtoul(pData, &ep, 10);
const char* cp = ep;
if (cp == pData) {
if (lineNum) {
fprintf(stderr, OUT_TAG ": malformed tag number on line %d\n", lineNum);
}
@ -273,14 +281,13 @@ static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
}
const char* tag = cp;
// Determine whether "c" is a valid tag char.
while (isalnum(*++cp) || (*cp == '_')) {
}
cp = endOfTag(cp);
size_t tagLen = cp - tag;
if (!isspace(*cp)) {
if (lineNum) {
fprintf(stderr, OUT_TAG ": invalid tag chars on line %d\n", lineNum);
fprintf(stderr, OUT_TAG ": invalid tag char %c on line %d\n", *cp,
lineNum);
}
errno = EINVAL;
return -1;
@ -311,9 +318,9 @@ static int scanTagLine(EventTagMap* map, char** pData, int lineNum) {
while (*cp != '\n') ++cp;
#ifdef DEBUG
fprintf(stderr, "%d: %p: %.*s\n", lineNum, tag, (int)(cp - *pData), *pData);
fprintf(stderr, "%d: %p: %.*s\n", lineNum, tag, (int)(cp - pData), pData);
#endif
*pData = cp;
pData = cp;
if (lineNum) {
if (map->emplaceUnique(tagIndex,
@ -341,9 +348,9 @@ static const char* eventTagFiles[NUM_MAPS] = {
// Parse the tags out of the file.
static int parseMapLines(EventTagMap* map, size_t which) {
char* cp = static_cast<char*>(map->mapAddr[which]);
const char* cp = static_cast<char*>(map->mapAddr[which]);
size_t len = map->mapLen[which];
char* endp = cp + len;
const char* endp = cp + len;
// insist on EOL at EOF; simplifies parsing and null-termination
if (!len || (*(endp - 1) != '\n')) {
@ -370,7 +377,7 @@ static int parseMapLines(EventTagMap* map, size_t which) {
lineStart = false;
} else if (isdigit(*cp)) {
// looks like a tag; scan it out
if (scanTagLine(map, &cp, lineNum) != 0) {
if (scanTagLine(map, cp, lineNum) != 0) {
if (!which || (errno != EMLINK)) {
return -1;
}
@ -495,14 +502,13 @@ static const TagFmt* __getEventTag(EventTagMap* map, unsigned int tag) {
int ret = asprintf(&buf, command_template, tag);
if (ret > 0) {
// Add some buffer margin for an estimate of the full return content.
char* cp;
size_t size =
ret - strlen(command_template) +
strlen("65535\n4294967295\t?\t\t\t?\t# uid=32767\n\n\f?success?");
if (size > (size_t)ret) {
cp = static_cast<char*>(realloc(buf, size));
if (cp) {
buf = cp;
char* np = static_cast<char*>(realloc(buf, size));
if (np) {
buf = np;
} else {
size = ret;
}
@ -512,10 +518,12 @@ static const TagFmt* __getEventTag(EventTagMap* map, unsigned int tag) {
// Ask event log tag service for an existing entry
if (__send_log_msg(buf, size) >= 0) {
buf[size - 1] = '\0';
unsigned long val = strtoul(buf, &cp, 10); // return size
char* ep;
unsigned long val = strtoul(buf, &ep, 10); // return size
const char* cp = ep;
if ((buf != cp) && (val > 0) && (*cp == '\n')) { // truncation OK
++cp;
if (!scanTagLine(map, &cp, 0)) {
if (!scanTagLine(map, cp, 0)) {
free(buf);
return map->find(tag);
}
@ -573,8 +581,9 @@ LIBLOG_ABI_PUBLIC const char* android_lookupEventTag(const EventTagMap* map,
LIBLOG_ABI_PUBLIC int android_lookupEventTagNum(EventTagMap* map,
const char* tagname,
const char* format, int prio) {
size_t len = strlen(tagname);
if (!len) {
const char* ep = endOfTag(tagname);
size_t len = ep - tagname;
if (!len || *ep) {
errno = EINVAL;
return -1;
}

2
logcat/tests/logcat_test.cpp
View file

@ -1677,7 +1677,7 @@ TEST(logcat, descriptive) {
// Invent new entries because existing can not serve
EventTagMap* map = android_openEventTagMap(nullptr);
ASSERT_TRUE(nullptr != map);
static const char name[] = ___STRING(logcat) "_descriptive_monotonic";
static const char name[] = ___STRING(logcat) ".descriptive-monotonic";
int myTag = android_lookupEventTagNum(map, name, "(new|1|s)",
ANDROID_LOG_UNKNOWN);
android_closeEventTagMap(map);