[LEDE-DEV] [PATCH ubox v2] logread: Add support for output template
Henry Chang
mr.changyuheng at gmail.com
Mon May 1 18:41:54 PDT 2017
Hi Philip,
Thanks for reviewing.
I re-submitted it here:
http://lists.infradead.org/pipermail/lede-dev/2017-May/007241.html
The only thing I didn't do is fmemopen() because I didn't see any
examples in the project.
Regards,
Henry Jr.
On Mon, May 1, 2017 at 10:48 AM, Philip Prindeville
<philipp_subx at redfish-solutions.com> wrote:
> Inline…
>
>
>> On Apr 27, 2017, at 5:33 PM, Henry Chang <mr.changyuheng at gmail.com> wrote:
>>
>> From: Henry Chang <mr.changyuheng at gmail.com>
>>
>> Signed-off-by: Henry Chang <mr.changyuheng at gmail.com>
>> ---
>> log/logread.c | 153 ++++++++++++++++++++++++++++++++++++++++++++++++----------
>> 1 file changed, 127 insertions(+), 26 deletions(-)
>>
>> diff --git a/log/logread.c b/log/logread.c
>> index edac1d9..3e3406a 100644
>> --- a/log/logread.c
>> +++ b/log/logread.c
>> @@ -56,10 +56,25 @@ static const struct blobmsg_policy log_policy[] = {
>> [LOG_TIME] = { .name = "time", .type = BLOBMSG_TYPE_INT64 },
>> };
>>
>> +enum {
>> + TPL_FIELD_MESSAGE,
>> + TPL_FIELD_PRIORITY,
>> + TPL_FIELD_SOURCE,
>> + TPL_FIELD_TIMESTAMP,
>> +};
>> +
>> +static const char *TPL_FIELDS[] = {
>> + [TPL_FIELD_MESSAGE] = "%message%",
>> + [TPL_FIELD_PRIORITY] = "%priority%",
>> + [TPL_FIELD_SOURCE] = "%source%",
>> + [TPL_FIELD_TIMESTAMP] = "%timestamp%",
>> +};
>> +
>> static struct uloop_timeout retry;
>> static struct uloop_fd sender;
>> static regex_t regexp_preg;
>> static const char *log_file, *log_ip, *log_port, *log_prefix, *pid_file, *hostname, *regexp_pattern;
>> +static const char *log_template;
>> static int log_type = LOG_STDOUT;
>> static int log_size, log_udp, log_follow, log_trailer_null = 0;
>> static int log_timestamp;
>> @@ -102,6 +117,7 @@ static int log_notify(struct blob_attr *msg)
>> struct stat s;
>> char buf[512];
>> char buf_ts[32];
>> + char buf_p[32];
>> uint32_t p;
>> char *str;
>> time_t t;
>> @@ -137,34 +153,108 @@ static int log_notify(struct blob_attr *msg)
>> regexec(®exp_preg, m, 0, NULL, 0) == REG_NOMATCH)
>> return 0;
>> t = blobmsg_get_u64(tb[LOG_TIME]) / 1000;
>> - if (log_timestamp) {
>> - t_ms = blobmsg_get_u64(tb[LOG_TIME]) % 1000;
>> - snprintf(buf_ts, sizeof(buf_ts), "[%lu.%03u] ",
>> - (unsigned long)t, t_ms);
>> - }
>> + t_ms = blobmsg_get_u64(tb[LOG_TIME]) % 1000;
>> + snprintf(buf_ts, sizeof(buf_ts), "[%lu.%03u] ", (unsigned long) t, t_ms);
>> c = ctime(&t);
>> p = blobmsg_get_u32(tb[LOG_PRIO]);
>> c[strlen(c) - 1] = '\0';
>> str = blobmsg_format_json(msg, true);
>> + snprintf(buf_p, sizeof buf_p, "%u", p);
>
> Even on an 64BIT architecture, an unsigned will be 32-bits and therefore 10 decimal digits plus NUL… not sure why buf_p[] needs to be so large.
>
>
>> +
>> + if (log_template) {
>> + char buf2[512];
>> + size_t len;
>> + int tpli = -1;
>> +
>> + if ((len = strlen(log_template) + 1) > sizeof buf) {
>> + fprintf(stderr, "template is larger than the internal buffer\n");
>> + return 1;
>> + }
>> + strncpy(buf, log_template, len);
>> +
>> + char *substr = buf;
>> + for (;;) {
>> + char *substrnext = NULL;
>> + for (int i = 0; i < sizeof TPL_FIELDS / sizeof (char *); ++i) {
>
>
> If ‘i’ is always a positive value, why not make it unsigned?
>
>
>> + char *substrbuf = strstr(substr, TPL_FIELDS[i]);
>> + if (!substrbuf)
>> + continue;
>> + if (!substrnext || substrbuf < substrnext) {
>> + substrnext = substrbuf;
>> + tpli = i;
>> + }
>> + }
>> + substr = substrnext;
>> + if (!substr)
>> + break;
>> + char *field = NULL;
>> + switch (tpli) {
>
>
> The rest of this file matches switch/case indent… please go with that.
>
>
>> + case TPL_FIELD_MESSAGE:
>> + field = m;
>> + break;
>> + case TPL_FIELD_PRIORITY:
>> + field = buf_p;
>> + break;
>> + case TPL_FIELD_SOURCE:
>> + switch (blobmsg_get_u32(tb[LOG_SOURCE])) {
>> + case SOURCE_KLOG:
>> + field = "kernel";
>> + break;
>> + case SOURCE_SYSLOG:
>> + field = "syslog";
>> + break;
>> + case SOURCE_INTERNAL:
>> + field = "internal";
>> + break;
>> + default:
>> + field = "-“;
>
>
> Please use a ‘break’ even on the last case of a ‘switch’.
>
>
>> + }
>> + case TPL_FIELD_TIMESTAMP:
>> + field = buf_ts;
>> + break;
>> + }
>> + if (!field || tpli < 0)
>> + continue;
>> + *buf2 = '\0';
>> + size_t fieldlen = strlen(field);
>> + strncat(buf2, buf, substr - buf);
>> + if (strlen(buf2) + fieldlen + 1 > sizeof buf2) {
>
> I would take the strlen() and assign it to a variable. This makes debugging simpler.
>
>
>> + fprintf(stderr, "template is larger than the internal buffer\n");
>> + return 1;
>> + }
>> + strncat(buf2, field, fieldlen);
>> + len = strlen(TPL_FIELDS[tpli]);
>> + if (strlen(buf2) + strlen(substr) - len + 1 > sizeof buf2) {
>
> Ditto.
>
>
>> + fprintf(stderr, "template is larger than the internal buffer\n");
>> + return 1;
>> + }
>> + strncat(buf2, substr + len, strlen(substr) - len);
>
>
> strlen() isn’t cheap. Please don’t call it multiple times. Save it into a variable and use that.
>
>
>> + strncpy(buf, buf2, strlen(buf2) + 1);
>> + substr += fieldlen;
>> + }
>> + }
>> +
>> if (log_type == LOG_NET) {
>> int err;
>>
>> - snprintf(buf, sizeof(buf), "<%u>", p);
>> - strncat(buf, c + 4, 16);
>> - if (log_timestamp) {
>> - strncat(buf, buf_ts, sizeof(buf) - strlen(buf) - 1);
>> + if (!log_template) {
>> + snprintf(buf, sizeof(buf), "<%u>", p);
>> + strncat(buf, c + 4, 16);
>
>
> Please avoid magic numbers, even if they were in the original code.
>
>
>
>> + if (log_timestamp) {
>> + strncat(buf, buf_ts, sizeof(buf) - strlen(buf) - 1);
>> + }
>> + if (hostname) {
>> + strncat(buf, hostname, sizeof(buf) - strlen(buf) - 1);
>> + strncat(buf, " ", sizeof(buf) - strlen(buf) - 1);
>> + }
>> + if (log_prefix) {
>> + strncat(buf, log_prefix, sizeof(buf) - strlen(buf) - 1);
>> + strncat(buf, ": ", sizeof(buf) - strlen(buf) - 1);
>> + }
>> + if (blobmsg_get_u32(tb[LOG_SOURCE]) == SOURCE_KLOG)
>> + strncat(buf, "kernel: ", sizeof(buf) - strlen(buf) - 1);
>> + strncat(buf, m, sizeof(buf) - strlen(buf) - 1);
>
>
> I’m looking at all these strncat()’s and thinking that you’d be better off using fmemopen() instead. Less chance of overrunning a buffer since all of that is taken care of for you.
>
>
>
>> }
>> - if (hostname) {
>> - strncat(buf, hostname, sizeof(buf) - strlen(buf) - 1);
>> - strncat(buf, " ", sizeof(buf) - strlen(buf) - 1);
>> - }
>> - if (log_prefix) {
>> - strncat(buf, log_prefix, sizeof(buf) - strlen(buf) - 1);
>> - strncat(buf, ": ", sizeof(buf) - strlen(buf) - 1);
>> - }
>> - if (blobmsg_get_u32(tb[LOG_SOURCE]) == SOURCE_KLOG)
>> - strncat(buf, "kernel: ", sizeof(buf) - strlen(buf) - 1);
>> - strncat(buf, m, sizeof(buf) - strlen(buf) - 1);
>> if (log_udp)
>> err = write(sender.fd, buf, strlen(buf));
>> else {
>> @@ -183,11 +273,18 @@ static int log_notify(struct blob_attr *msg)
>> uloop_timeout_set(&retry, 1000);
>> }
>> } else {
>> - snprintf(buf, sizeof(buf), "%s %s%s.%s%s %s\n",
>> - c, log_timestamp ? buf_ts : "",
>> - getcodetext(LOG_FAC(p) << 3, facilitynames),
>> - getcodetext(LOG_PRI(p), prioritynames),
>> - (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("") : (" kernel:"), m);
>> + if (!log_template) {
>> + snprintf(buf, sizeof(buf), "%s %s%s.%s%s %s\n",
>> + c, log_timestamp ? buf_ts : "",
>> + getcodetext(LOG_FAC(p) << 3, facilitynames),
>> + getcodetext(LOG_PRI(p), prioritynames),
>> + (blobmsg_get_u32(tb[LOG_SOURCE])) ? ("") : (" kernel:"), m);
>> + } else {
>> + size_t buflen = strlen(buf);
>> + buflen = buflen <= sizeof buf - 2 ? buflen : sizeof buf - 2;
>
> Need parens. Also much more clear as
>
> buflen = (buflen <= (sizeof(buf) - 2)) ? buflen : (sizeof(buf) - 2);
>
>
>> + buf[buflen] = '\n’;
>
> buflen++ ?
>
>
>> + buf[buflen+1] = '\0’;
>
> Ditto.
>
>
>> + }
>> ret = write(sender.fd, buf, strlen(buf));
>> }
>>
>> @@ -211,6 +308,7 @@ static int usage(const char *prog)
>> " -p <file> PID file\n"
>> " -h <hostname> Add hostname to the message\n"
>> " -P <prefix> Prefix custom text to streamed messages\n"
>> + " -T <template> Custom log output template\n"
>> " -f Follow log messages\n"
>> " -u Use UDP as the protocol\n"
>> " -t Add an extra timestamp\n"
>> @@ -260,7 +358,7 @@ int main(int argc, char **argv)
>>
>> signal(SIGPIPE, SIG_IGN);
>>
>> - while ((ch = getopt(argc, argv, "u0fcs:l:r:F:p:S:P:h:e:t")) != -1) {
>> + while ((ch = getopt(argc, argv, "u0fcs:l:r:F:p:S:P:h:e:tT:")) != -1) {
>> switch (ch) {
>> case 'u':
>> log_udp = 1;
>> @@ -307,6 +405,9 @@ int main(int argc, char **argv)
>> case 't':
>> log_timestamp = 1;
>> break;
>> + case 'T':
>> + log_template = optarg;
>> + break;
>> default:
>> return usage(*argv);
>> }
>> --
>> 2.7.4
>>
>>
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>> Lede-dev at lists.infradead.org
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>
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