>-----Original Message-----
>From: Stephen Hemminger [mailto:step...@networkplumber.org]
>Sent: Wednesday, February 1, 2017 5:54 PM
>To: Mrozowicz, SlawomirX <slawomirx.mrozow...@intel.com>; Doherty,
>Declan <declan.dohe...@intel.com>
>Cc: dev@dpdk.org
>Subject: bugs and glitches in rte_cryptodev_devices_get
>
>The function rte_cryptodev_devices_get has several issues. I was just going
>to fix it, but think it need to be explained.
>
>One potentially serious one (reported by coverity) is:
>
>*** CID 141067: (BAD_COMPARE)
>/lib/librte_cryptodev/rte_cryptodev.c: 503 in rte_cryptodev_devices_get()
>497 && (*devs + i)->attached ==
>498 RTE_CRYPTODEV_ATTACHED)
>{
>499
>500 dev = (*devs + i)->device;
>501
>502 if (dev)
>>>> CID 141067: (BAD_COMPARE)
>>>> Truncating the result of "strncmp" to "unsigned char" may cause it to
>>>> be
>misinterpreted as 0. Note that "strncmp" may return an integer besides -1, 0,
>or 1.
>503 cmp = strncmp(dev->driver->name,
>504 dev_name,
>505 strlen(dev_name));
>506 else
>507 cmp = strncmp((*devs + i)->data->name,
>508 dev_name,
>/lib/librte_cryptodev/rte_cryptodev.c: 507 in rte_cryptodev_devices_get()
>501
>502 if (dev)
>503 cmp = strncmp(dev->driver->name,
>504 dev_name,
>505 strlen(dev_name));
>506 else
>>>> CID 141067: (BAD_COMPARE)
>>>> Truncating the result of "strncmp" to "unsigned char" may cause it to
>>>> be
>misinterpreted as 0. Note that "strncmp" may return an integer besides -1, 0,
>or 1.
>507 cmp = strncmp((*devs + i)->data->name,
>508 dev_name,
>509 strlen(dev_name));
>510
>511 if (cmp == 0)
>512 devices[count++] = (*devs +
>i)->data->dev_id;
>
>
>But also:
>
>1. Incorrect function signature:
> * function returns int but never a negative value. should be unsigned.
> * devices argument is not modified should be const.
>
>2. Original ABI seems short sighted with limit of 256 cryptodevs
> * this seems like 8 bit mindset, should really use unsigned int instead
> of uint8_t for number of devices.
>
>3. Wacky indention of the if statement.
>
>4. Make variables local to the block they are used (cmp, dev)
>
>5. Use array instead of pointer:
> ie. instead of *devs + i use devs[i]
>
We reconsider your suggestions and we addressed all your changes except add the
const of the devices argument, since in our opinion it is not necessary.
>
>The overall code in question is:
>
>
>int
>rte_cryptodev_devices_get(const char *dev_name, uint8_t *devices,
> uint8_t nb_devices)
>{
> uint8_t i, cmp, count = 0;
> struct rte_cryptodev **devs = &rte_cryptodev_globals->devs;
> struct rte_device *dev;
>
> for (i = 0; i < rte_cryptodev_globals->max_devs && count <
>nb_devices;
> i++) {
>
> if ((*devs + i)
> && (*devs + i)->attached ==
> RTE_CRYPTODEV_ATTACHED)
>{
>
> dev = (*devs + i)->device;
>
> if (dev)
> cmp = strncmp(dev->driver->name,
> dev_name,
> strlen(dev_name));
> else
> cmp = strncmp((*devs + i)->data->name,
> dev_name,
> strlen(dev_name));
>
> if (cmp == 0)
> devices[count++] = (*devs + i)->data->dev_id;
> }
> }
>
> return count;
>}
>
>Please fix it.
>
