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Getting a network trace from a single application

jonasdn.blogspot.com

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Re: Getting a network trace from a single application

#2

Post by ckastner »

Looks very nice!

One thing: the "Handle exceptions of setuid() and setgid()" commit message caught my eye, so I took a look:

  if (setuid(uid)
You probably want to add an exit() here, as well as to the preceeding setgid() call. Also, the earlier initgroups() can fail, too, so its result should also be checked.

Re: Getting a network trace from a single application

#5

Post by heinrich5991 »

ckastner wrote: post #2

Looks very nice! One thing: the "Handle exceptions of setuid() and setgid()" commit message caught my eye, so I took a look: if (setuid(uid) You probably want to add an exit() here, as well as to the preceeding setgid() call. Also, the earlier initgroups() can fail, too, so its result should also be checked.

Looks like a '\n' is missing there.

Re: Getting a network trace from a single application

#6

Post by rincebrain »

andrewstuart2 wrote: post #4
mrb wrote: post #3

Cool! Namespace are a powerful but not very well known feature of Linux.

Well, unless you count docker, rkt, and the whole linux containers thing.

There are a number of consumers of namespaces, particularly of late, but they've been around (depending on which type) for years at this point, and many users (or even admins) have little knowledge of their existence or usage unless it comes time to deploy $CONTAINER and their platform does not have them enabled.

Re: Getting a network trace from a single application

#7

Post by jakobdabo »

ckastner wrote: post #2

Looks very nice! One thing: the "Handle exceptions of setuid() and setgid()" commit message caught my eye, so I took a look: if (setuid(uid) You probably want to add an exit() here, as well as to the preceeding setgid() call. Also, the earlier initgroups() can fail, too, so its result should also be checked.

While we are doing this...

    #define APP_TIMEOUT (2000000L) /* 2 seconds */
    ...
    usleep(APP_TIMEOUT);
usleep limits its argument's range to values from 0 to 1000000 and is considered obsolete. Please use nanosleep instead.

Re: Getting a network trace from a single application

#8

Post by jonasdn »

jakobdabo wrote: post #7
ckastner wrote: post #2

Looks very nice! One thing: the "Handle exceptions of setuid() and setgid()" commit message caught my eye, so I took a look: if (setuid(uid) You probably want to add an exit() here, as well as to the preceeding setgid() call. Also, the earlier initgroups() can fail, too, so its result should also be checked.

While we are doing this... #define APP_TIMEOUT (2000000L) /* 2 seconds */ ... usleep(APP_TIMEOUT); usleep limits its argument's range to values from 0 to 1000000 and is considered obsolete. Please use nanosleep instead.

Thank you, applied :)
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