On Tuesday 05 August 2014 14:27:57 you wrote: > I disagree. There is nothing to reject here. It fixes _my issue_ at hand. > If you want to fix other bugs in your system that you are facing in > reality, by all means, fix them in a separate change. > > I definitely do not agree with dynamically allocated buffer for the simple > reasons of: > > 1) Slow. > 2) You would still need a maximum anyway. > 3) Needless code complication. > > Let us keep things simple and good, you know the good old KISS principle. > > P.S.: please do not bikeshed. > > > On Tue, Aug 5, 2014 at 1:17 PM, tito <farmat...@tiscali.it> wrote: > > > On Tuesday 05 August 2014 12:46:08 you wrote: > > > Here is my tested fix without being to debug the busybox code, so only > > code > > > reading and understanding were my friends: > > > > > > commit 9610650b6ce2a4c1904f78a2dcdb47cad3d2e3d1 > > > Author: Laszlo Papp <lp...@kde.org> > > > Date: Tue Aug 5 11:42:24 2014 +0100 > > > > > > Allow 256 bytes long usernames as per Unix standards (usually) > > > > > > diff --git a/libpwdgrp/pwd_grp.c b/libpwdgrp/pwd_grp.c > > > index 2060d78..368c252 100644 > > > --- a/libpwdgrp/pwd_grp.c > > > +++ b/libpwdgrp/pwd_grp.c > > > @@ -23,8 +23,8 @@ > > > /**********************************************************************/ > > > /* Sizes for statically allocated buffers. */ > > > > > > -#define PWD_BUFFER_SIZE 256 > > > -#define GRP_BUFFER_SIZE 256 > > > +#define PWD_BUFFER_SIZE LOGIN_NAME_MAX+256 > > > +#define GRP_BUFFER_SIZE LOGIN_NAME_MAX+256 > > > > > > /**********************************************************************/ > > > /* Prototypes for internal functions. */ > > > > > > > Hi, > > yes I've thought also about this solution but rejected it because: > > > > 1) there will not be enough space to hold the home dir if named the same > > as the user > > so you need at least: > > > > #define PWD_BUFFER_SIZE LOGIN_NAME_MAX+ 6 (for home) + LOGIN_NAME_MAX (or > > PATH_MAX?) + 256 (for the rest) > > > > yet this might not be enough as in my passwd file I see a 101 char long > > passwd. > > Add the gecos fields (arbitrary lenght) to it and the default shell > > and we are short on space again. > > > > 2) same for #define GRP_BUFFER_SIZE LOGIN_NAME_MAX+256: > > here you need to take into account the group member list with > > an arbitrary number of members: > > > > > > #define GRP_BUFFER_SIZE LOGIN_NAME_MAX+256+ LOGIN_NAME_MAX*n: > > > > The only clean solution to fix it forever is dynamically allocated buffers > > created at the time you read in the line from the passwd files. > > > > Ciao, > > Tito > > > > > > P.S.: please don't top post. > > > > > > > > > > On Tue, Aug 5, 2014 at 11:22 AM, Laszlo Papp <lp...@kde.org> wrote: > > > > > > > Yeah, mayhaps... Thanks for the prompt reply. I tried to debug the > > code, > > > > but the busybox code here is a bit messy heavily abusing macros in C > > and > > > > all that. It ain't easy I must confess! > > > > > > > > For instance, see this section: > > > > > > > > http://git.busybox.net/busybox/tree/libpwdgrp/pwd_grp.c#n227 > > > > > > > > The _source_ is included several times always getting a new meaning > > based > > > > on some defines... Now, check this function: > > > > > > > > http://git.busybox.net/busybox/tree/libpwdgrp/pwd_grp_internal.c#n20 > > > > > > > > "resultbuf" will be always different depending on which include it is. > > > > Since it is failing at the pw_name check in there, I wanted to print it > > > > out, but no easy joy there as printing it like that will yield > > compilation > > > > error when the file is being included next time from above. > > > > > > > > Right, I thought instead of doing some "#if a == b" hackery, debugging > > > > would be easier, BUT: > > > > > > > > 1) The default build is stripped, yuck! > > > > > > > > 2) The unstripped build cannot locate the symbols (*). > > > > > > > > So, I am giving up on this for now; this is not the type of source code > > > > that is so pleasant to work with. ;-) > > > > > > > > Cheers, L. > > > > > > > > * (gdb) b main > > > > > > > > Breakpoint 2 at 0x407c71 > > > > (gdb) r > > > > Starting program: /home/lpapp/Projects/busybox/busybox_unstripped > > deluser > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > > warning: Could not load shared library symbols for linux-vdso.so.1. > > > > Do you need "set solib-search-path" or "set sysroot"? > > > > > > > > Breakpoint 2, 0x0000000000407c71 in main () > > > > (gdb) list > > > > No symbol table is loaded. Use the "file" command. > > > > (gdb) > > > > > > > > > > > > > > > > On Mon, Aug 4, 2014 at 10:40 PM, tito <farmat...@tiscali.it> wrote: > > > > > > > >> On Monday 04 August 2014 19:06:39 Laszlo Papp wrote: > > > >> > Hi, > > > >> > > > > >> > sudo busybox adduser > > > >> > > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> > passwd: unknown user > > > >> > > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> > > > > >> > Yet, the user is created in /etc/shadow: > > > >> > > > > >> > > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff:!:16286:0:99999:7::: > > > >> > > > > >> > This is at least one issue, but there is another here: > > > >> > > > > >> > sudo busybox deluser > > > >> > > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> > deluser: unknown user > > > >> > > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> > > > > >> > So, basically, once you create that long username, you cannot > > remove it > > > >> > anymore with busybox and it keeps polluting your system. > > > >> > > > > >> > You have to gain other means to clean up! I am using this version > > over > > > >> here: > > > >> > > > > >> > BusyBox v1.22.1 (2014-06-02 14:47:37 MSK) multi-call binary. > > > >> > > > > >> > Could you please look into this and potentially fix it? Thanks in > > > >> advance. > > > >> > > > > >> > Cheers, L. > > > >> > > > > >> Hi, > > > >> if disabling libb's internal pwd/grp lib and by jumping through some > > hops > > > >> it > > > >> works for me: > > > >> > > > >> I need to add the group first as my system's groupadd command called > > by > > > >> bb's adduser > > > >> supports only groupnames of max 32 chars. > > > >> > > > >> ./busybox addgroup > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> ./busybox adduser > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> -G > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> Adding user > > > >> > > `fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff' > > > >> to group > > > >> > > `fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff' > > > >> ... > > > >> Adding user > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> to group > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> Done. > > > >> Enter new UNIX password: > > > >> Retype new UNIX password: > > > >> passwd: password updated successfully > > > >> > > > >> and then I could also delete it: > > > >> > > > >> ./busybox deluser > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> ./busybox delgroup > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> delgroup: unknown group > > > >> > > fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff > > > >> > > > >> (deluser correctly deleted also the group) > > > >> > > > >> I suspect that the buffer size used in libbpwdgrp/pwd_grp.c is to > > small: > > > >> > > > >> #define PWD_BUFFER_SIZE 256 > > > >> #define GRP_BUFFER_SIZE 256 > > > >> > > > >> as it is meant for the whole struct pw passwd (or struct gr group) > > fields > > > >> which could be easily be bigger: > > > >> > > > >> grep ffff* /etc/shadow | wc > > > >> 1 1 240 > > > >> grep ffff* /etc/passwd | wc > > > >> 1 2 286 > > > >> > > > >> I think that the buffers' size must be increased for example to: > > > >> > > > >> #define PWD_BUFFER_SIZE LOGIN_NAME_MAX+LOGIN_NAME_MAX+256 > > > >> > > > >> we need one LOGIN_NAME_MAX size for the login and one more for the > > home > > > >> dir > > > >> if same as login, plus 256 for the remaining data (passwd, gecos, > > shell, > > > >> etc). > > > >> > > > >> #define GRP_BUFFER_SIZE LOGIN_NAME_MAX+256+LOGIN_NAME_MAX*n (?) > > > >> > > > >> we need one LOGIN_NAME_MAX size for the group name (for which we > > > >> actually enforce the same size as for the username) plus 256 for the > > > >> remaining data > > > >> plus LOGIN_NAME_MAX * n group member names. > > > >> > > > >> So for my limited understanding using static buffers here is rather > > > >> difficult > > > >> as the size of data is not easily predictable. > > > >> I don't know how real libc manages it (maybe realloc on ERANGE?) > > > >> > > > >> Your particular example for me is fixed by using. > > > >> > > > >> #define PWD_BUFFER_SIZE 1024 > > > >> > > > >> #define GRP_BUFFER_SIZE 1024 > > > >> > > > >> But to me it seems not an optimal solution, > > > >> so other more experienced developers should > > > >> take a look at it. > > > >> > > > >> Hope this helps. > > > >> Ciao, > > > >> Tito > > > >> > > > >> PS: in libbbpwdgrp functions we need to check for errors: > > > >> > > > >> 0 or ENOENT or ESRCH or EBADF or EPERM or ... > > > >> The given name or gid was not found. > > > >> > > > >> EINTR A signal was caught. > > > >> > > > >> EIO I/O error. > > > >> > > > >> EMFILE The maximum number (OPEN_MAX) of files was open already > > in > > > >> the calling process. > > > >> > > > >> ENFILE The maximum number of files was open already in the > > system. > > > >> > > > >> ENOMEM Insufficient memory to allocate group structure. > > > >> > > > >> ERANGE Insufficient buffer space supplied. > > > >> > > > >> as for example the xgroup_study function in the addgroup applet > > > >> assigns a wrong gid if getgrgid fails for example for ERANGE > > > >> > > > >> /* Check if the desired gid is free > > > >> * or find the first free one */ > > > >> while (1) { > > > >> printf("gid %d\n", g->gr_gid); > > > >> if (!getgrgid(g->gr_gid)) { > > > >> return; /* found free group: return */ > > > >> } > > > >> > > > >> Hi, I doubt it fixes your issue because I tested the same fix and it did in fact fail. Please test:
1) ./busybox addgroup LONGUSERNAME (this fails in subtle ways as a already in use gid is assigned) 2) ./busybox adduser LONGUSERNAME -G LONGUSERNAME 3) ./busybox deluser LONGUSERNAME 4) ./busybox delgroup LONGUSERNAME Ciao, Tito _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox