On 6/15/2020 10:01 AM, Ivan Dyukov wrote:
> This commit add function which treat link status structure
> and format it to text representation.
If I am following correctly, the initial need was to escape from speed checks
everytime loging link information caused by this new 'unknown' speed.
And later suggestion was to have a pre-formatted text for link logging.
This patch brings additional link status printing/formatting capability with
custom format string support and with new format specifiers for link (like, '%D'
link duplex state),
although this is nice work and thanks for it, I am not sure this complexity and
two new APIs are really needed.
For me only 'rte_eth_link_format()' without custom format support looks good
enough but I won't object if the concensus is to have them.
I am aware there are multiple applications you are updating logging slightly
different which requires this flexibility but what happens if they use same
pre-formatted text, is that difference really required or happened by time based
on developers taste?
I will put some comments below in any case.
>
> Signed-off-by: Ivan Dyukov <i.dyu...@samsung.com>
<...>
> @@ -249,6 +249,9 @@ SRCS-$(CONFIG_RTE_LIBRTE_SECURITY) += test_security.c
>
> SRCS-$(CONFIG_RTE_LIBRTE_IPSEC) += test_ipsec.c test_ipsec_perf.c
> SRCS-$(CONFIG_RTE_LIBRTE_IPSEC) += test_ipsec_sad.c
> +
> +SRCS-$(CONFIG_RTE_LIBRTE_ETHER) += test_ethdev_link.c
+1 to unit test.
<...>
> +int
> +rte_eth_link_printf(const char *const fmt,
> + struct rte_eth_link *link)
> +{
> + char text[200];
> + int ret;
> + ret = rte_eth_link_format(text, 200, fmt, link);
Will it be paranoid to add "text[199] = 0" to be sure any custom 'fmt' won't
cause any harm?
> + printf("%s", text);
Not sure if the error still should be printed on error case?
Like for example what the code does when fmt="%X"?
> + return ret;
> +}
> +
> +int
> +rte_eth_link_format(char *str, int32_t len, const char *const fmt,
> + struct rte_eth_link *link)
Why not have the 'len' type 'size_t'?
> + int offset = 0;
> + int32_t clen = len;
> + const char *fmt_cur = fmt;
> + double gbits = (double)link->link_speed / 1000.;
> + /* TBD: make it international? */
> + static const char LINK_DOWN_STR[] = "Link down";
> + static const char LINK_UP_STR[] = "Link up at ";
> + static const char UNKNOWN_SPEED_STR[] = "Unknown speed";
> + static const char MBITS_STR[] = "Mbit/s";
> + static const char GBITS_STR[] = "Gbit/s";
> + static const char AUTONEG_STR[] = "Autoneg";
> + static const char FIXED_STR[] = "Fixed";
> + static const char FDX_STR[] = "FDX";
> + static const char HDX_STR[] = "HDX";
> + static const char UNKNOWN_STR[] = "Unknown";
> + static const char UP_STR[] = "Up";
> + static const char DOWN_STR[] = "Down";
> + if (str == NULL || len == 0)
> + return -1;
> + /* default format string, if no fmt is specified */
> + if (fmt == NULL) {
> + if (link->link_status == ETH_LINK_DOWN)
> + return snprintf(str, (size_t)clen, "%s", LINK_DOWN_STR);
> +
> + offset = snprintf(str, (size_t)clen, "%s", LINK_UP_STR);
> + if (offset < 0 || (clen - offset) <= 0)
> + return -1;
> + clen -= offset;
> + str += offset;
> + if (link->link_speed == ETH_SPEED_NUM_UNKNOWN) {
> + offset = snprintf(str, clen, "%s",
> + UNKNOWN_SPEED_STR);
> + if (offset < 0 || (clen - offset) <= 0)
> + return -1;
better to use 'strlcpy' & 'strlcat', they are easier to use for these kind of
checks.
<...>
> + /* Formated status */
> + } else {
> + char c = *fmt_cur;
> + while (c) {
> + if (clen <= 0)
> + return -1;
> + if (c == '%') {
> + c = *++fmt_cur;
> + switch (c) {
> + /* Speed in Mbits/s */
> + case 'M':
> + if (link->link_speed ==
> + ETH_SPEED_NUM_UNKNOWN)
> + offset = snprintf(str,
> + clen, "%s",
> + UNKNOWN_STR);
> + else
> + offset = snprintf(str,
> + clen, "%u",
> + link->link_speed);
Code readiblity is not great here because you hit the 80char limit, this is a
sign that something is wrong like function is already too long.
Can you please try to fix this, like extracting some part of the code to its own
function or return after end of the 'if' statement which can save one more level
indentation etc...
<...>
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index 2090af501..83291e656 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -2295,6 +2295,58 @@ int rte_eth_link_get(uint16_t port_id, struct
> rte_eth_link *link);
> */
> int rte_eth_link_get_nowait(uint16_t port_id, struct rte_eth_link *link);
>
> +
> +/**
> + * print formated link status to stdout. This function threats all
> + * special values like ETH_SPEED_NUM_UNKNOWN, ETH_LINK_DOWN etc. and convert
> + * them to textual representation.
> + *
> + * @param fmt
> + * Format string which allow to format link status. If NULL is provided
> + * , default formating will be applied.
> + * Following specifiers are available:
> + * - '%M' link speed in Mbits/s
> + * - '%G' link speed in Gbits/s
> + * - '%S' link status. e.g. Up or Down
> + * - '%A' link autonegotiation state
> + * - '%D' link duplex state
> + * @param link
> + * Link status provided by rte_eth_link_get function
> + * @return
> + * - Number of bytes written to stdout. In case of error, -1 is returned.
Does it worth to mention the log still will be printed on error?
> + *
> + */
> +int rte_eth_link_printf(const char *const fmt,
> + struct rte_eth_link *link);
> +
> +/**
> + * Format link status to textual representation. This function threats all
> + * special values like ETH_SPEED_NUM_UNKNOWN, ETH_LINK_DOWN etc. and convert
> + * them to textual representation.
> + *
> + * @param str
> + * A pointer to a string to be filled with textual representation of
> + * device status.
> + * @param len
> + * Length of available memory at 'str' string.
> + * @param fmt
> + * Format string which allow to format link status. If NULL is provided
> + * , default formating will be applied.
> + * Following specifiers are available:
> + * - '%M' link speed in Mbits/s
> + * - '%G' link speed in Gbits/s
> + * - '%S' link status. e.g. Up or Down
> + * - '%A' link autonegotiation state
> + * - '%D' link duplex state
> + * @param link
> + * Link status provided by rte_eth_link_get function
> + * @return
> + * - Number of bytes written to str array. In case of error, -1 is
> returned.
> + *
> + */
> +int rte_eth_link_format(char *str, int32_t len, const char *const fmt,
> + struct rte_eth_link *eth_link);
> +
These new APIs needs to be experimental by process (__rte_experimental).
Need the add these APIs to the .map file (rte_ethdev_version.map), so that they
will be exported in the dynamic library (.so).
