>Synopsis: Bad return value for getpwnam_r et al
>Category: 42
>Environment:
System : OpenBSD 5.4
Details : OpenBSD 5.4 (GENERIC.MP) #41: Tue Jul 30 15:30:02 MDT 2013
dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
Architecture: OpenBSD.amd64
Machine : amd64
>Description:
POSIX says "[t]he getpwnam_r() function shall return zero on success
or if the requested entry was not found and no error has occurred.
If an error has occurred, an error number shall be returned to
indicate the error."
However, OpenBSD returns 0 on success or 1 on failure; it doesn't
return an error number. Linux, OS X, Solaris, FreeBSD, and NetBSD
all return an error number, and in particular return ERANGE when the
provided buffer is too small.
Background: I was looping over getpwnam_r so I wouldn't have to use
sysconf() to get _SC_GETPW_R_SIZE_MAX. Linux/glibc has an annoying
habit of setting some limits to INT_MAX. It doesn't in this case,
but I'm not confident they won't do something stupid down the line.
>How-To-Repeat:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
int main(void) {
struct passwd ent, *found;
char *buf = NULL;
size_t bufsiz = 1;
int error;
found = NULL;
buf = malloc(bufsiz);
while ((error = getpwnam_r("root", &ent, buf, bufsiz, &found)))
{
fprintf(stderr, "bufsiz:%zu error:%s\n", bufsiz,
strerror(error));
bufsiz <<= 1;
buf = realloc(buf, bufsiz);
found = NULL;
}
printf("pw_dir: %s\n", ent.pw_dir);
printf("pw_shell: %s\n", ent.pw_shell);
return 0;
}
>Fix:
No easy fix. The supporting routines _pwhashbyname, _pwhashbyuid,
etc in lib/libc/gen/getpwent.c don't propogate error values.
dmesg:
OpenBSD 5.4 (GENERIC.MP) #41: Tue Jul 30 15:30:02 MDT 2013
dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 2130575360 (2031MB)
avail mem = 2066194432 (1970MB)
mainbus0 at root
bios0 at mainbus0
acpi at bios0 not configured
mpbios0 at bios0: Intel MP Specification 1.4
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Genuine Intel(R) CPU @ 1.60GHz, 600.10 MHz
cpu0:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,MOVBE,NXE,LONG,LAHF,PERF
cpu0: 512KB 64b/line 8-way L2 cache
cpu0: smt 0, core 0, package 0
cpu0: apic clock running at 100MHz
cpu1 at mainbus0: apid 1 (application processor)
cpu1: Genuine Intel(R) CPU @ 1.60GHz, 600.00 MHz
cpu1:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,MOVBE,NXE,LONG,LAHF,PERF
cpu1: 512KB 64b/line 8-way L2 cache
cpu1: smt 1, core 0, package 0
mpbios0: bus 0 is type PCI
mpbios0: bus 64 is type ISA
ioapic0 at mainbus0: apid 0 pa 0xfec00000, version 20, 24 pins
cpu0: unknown Enhanced SpeedStep CPU, msr 0x0615101c06000615
cpu0: using only highest and lowest power states
cpu0: Enhanced SpeedStep 600 MHz: speeds: 1600, 600 MHz
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "Intel E600 Host" rev 0x05
pchb1 at pci0 dev 1 function 0 "Intel E600 Config" rev 0x00
ppb0 at pci0 dev 23 function 0 "Intel E600 PCIE" rev 0x00
pci1 at ppb0 bus 1
ppb1 at pci1 dev 0 function 0 "Intel EG20T PCIE" rev 0x01
pci2 at ppb1 bus 2
"Intel EG20T Packet Hub" rev 0x01 at pci2 dev 0 function 0 not configured
"Intel EG20T Ethernet" rev 0x01 at pci2 dev 0 function 1 not configured
"Intel EG20T GPIO" rev 0x00 at pci2 dev 0 function 2 not configured
ohci0 at pci2 dev 2 function 0 "Intel EG20T USB" rev 0x01: apic 0 int 19,
version 1.0, legacy support
ohci1 at pci2 dev 2 function 1 "Intel EG20T USB" rev 0x01: apic 0 int 19,
version 1.0, legacy support
ohci2 at pci2 dev 2 function 2 "Intel EG20T USB" rev 0x01: apic 0 int 19,
version 1.0, legacy support
ehci0 at pci2 dev 2 function 3 "Intel EG20T USB" rev 0x01: apic 0 int 19
usb0 at ehci0: USB revision 2.0
uhub0 at usb0 "Intel EHCI root hub" rev 2.00/1.00 addr 1
"Intel EG20T USB Client" rev 0x01 at pci2 dev 2 function 4 not configured
sdhc0 at pci2 dev 4 function 0 "Intel EG20T SDIO" rev 0x01: apic 0 int 18
sdmmc0 at sdhc0
sdhc1 at pci2 dev 4 function 1 "Intel EG20T SDIO" rev 0x01: apic 0 int 18
sdmmc1 at sdhc1
ahci0 at pci2 dev 6 function 0 "Intel EG20T AHCI" rev 0x01: msi, AHCI 1.1
scsibus0 at ahci0: 32 targets
sd0 at scsibus0 targ 0 lun 0: <ATA, INTEL SSDSA2VP02, 9CV1> SCSI3 0/direct
fixed naa.5001517bb2898ff1
sd0: 19087MB, 512 bytes/sector, 39091248 sectors, thin
sd1 at scsibus0 targ 1 lun 0: <ATA, INTEL SSDSA2VP02, 9CV1> SCSI3 0/direct
fixed naa.5001517bb28994d3
sd1: 19087MB, 512 bytes/sector, 39091248 sectors, thin
ohci3 at pci2 dev 8 function 0 "Intel EG20T USB" rev 0x01: apic 0 int 16,
version 1.0, legacy support
ohci4 at pci2 dev 8 function 1 "Intel EG20T USB" rev 0x01: apic 0 int 16,
version 1.0, legacy support
ohci5 at pci2 dev 8 function 2 "Intel EG20T USB" rev 0x01: apic 0 int 16,
version 1.0, legacy support
ehci1 at pci2 dev 8 function 3 "Intel EG20T USB" rev 0x01: apic 0 int 16
usb1 at ehci1: USB revision 2.0
uhub1 at usb1 "Intel EHCI root hub" rev 2.00/1.00 addr 1
"Intel EG20T DMA" rev 0x00 at pci2 dev 10 function 0 not configured
puc0 at pci2 dev 10 function 1 "Intel EG20T Serial" rev 0x00: ports: 1 com
com4 at puc0 port 0 apic 0 int 19: ti16750, 64 byte fifo
puc1 at pci2 dev 10 function 2 "Intel EG20T Serial" rev 0x00: ports: 1 com
com5 at puc1 port 0 apic 0 int 19: ti16750, 64 byte fifo
puc2 at pci2 dev 10 function 3 "Intel EG20T Serial" rev 0x00: ports: 1 com
com6 at puc2 port 0 apic 0 int 19: ti16750, 64 byte fifo
puc3 at pci2 dev 10 function 4 "Intel EG20T Serial" rev 0x00: ports: 1 com
com7 at puc3 port 0 apic 0 int 19: ti16750, 64 byte fifo
"Intel EG20T DMA" rev 0x00 at pci2 dev 12 function 0 not configured
"Intel EG20T SPI" rev 0x00 at pci2 dev 12 function 1 not configured
"Intel EG20T I2C" rev 0x00 at pci2 dev 12 function 2 not configured
"Intel EG20T CAN" rev 0x00 at pci2 dev 12 function 3 not configured
"Intel EG20T 1588" rev 0x01 at pci2 dev 12 function 4 not configured
usb2 at ohci0: USB revision 1.0
uhub2 at usb2 "Intel OHCI root hub" rev 1.00/1.00 addr 1
usb3 at ohci1: USB revision 1.0
uhub3 at usb3 "Intel OHCI root hub" rev 1.00/1.00 addr 1
usb4 at ohci2: USB revision 1.0
uhub4 at usb4 "Intel OHCI root hub" rev 1.00/1.00 addr 1
usb5 at ohci3: USB revision 1.0
uhub5 at usb5 "Intel OHCI root hub" rev 1.00/1.00 addr 1
usb6 at ohci4: USB revision 1.0
uhub6 at usb6 "Intel OHCI root hub" rev 1.00/1.00 addr 1
usb7 at ohci5: USB revision 1.0
uhub7 at usb7 "Intel OHCI root hub" rev 1.00/1.00 addr 1
ppb2 at pci0 dev 24 function 0 "Intel E600 PCIE" rev 0x00
pci3 at ppb2 bus 3
ppb3 at pci3 dev 0 function 0 "IDT 89HPES4T4" rev 0x0e
pci4 at ppb3 bus 4
ppb4 at pci4 dev 2 function 0 "IDT 89HPES4T4" rev 0x0e
pci5 at ppb4 bus 5
em0 at pci5 dev 0 function 0 "Intel 82574L" rev 0x00: msi, address
00:00:24:cf:08:38
ppb5 at pci4 dev 3 function 0 "IDT 89HPES4T4" rev 0x0e
pci6 at ppb5 bus 6
em1 at pci6 dev 0 function 0 "Intel 82574L" rev 0x00: msi, address
00:00:24:cf:08:39
ppb6 at pci4 dev 4 function 0 "IDT 89HPES4T4" rev 0x0e
pci7 at ppb6 bus 7
ppb7 at pci0 dev 25 function 0 "Intel E600 PCIE" rev 0x00
pci8 at ppb7 bus 8
ppb8 at pci8 dev 0 function 0 "IDT 89HPES4T4" rev 0x0e
pci9 at ppb8 bus 9
ppb9 at pci9 dev 2 function 0 "IDT 89HPES4T4" rev 0x0e
pci10 at ppb9 bus 10
em2 at pci10 dev 0 function 0 "Intel 82574L" rev 0x00: msi, address
00:00:24:cf:08:3a
ppb10 at pci9 dev 3 function 0 "IDT 89HPES4T4" rev 0x0e
pci11 at ppb10 bus 11
em3 at pci11 dev 0 function 0 "Intel 82574L" rev 0x00: msi, address
00:00:24:cf:08:3b
ppb11 at pci9 dev 4 function 0 "IDT 89HPES4T4" rev 0x0e
pci12 at ppb11 bus 12
ppb12 at pci0 dev 26 function 0 "Intel E600 PCIE" rev 0x00
pci13 at ppb12 bus 13
vendor "Oxford", unknown product 0xc208 (class communications subclass serial,
rev 0x00) at pci13 dev 0 function 0 not configured
tcpcib0 at pci0 dev 31 function 0 "Intel E600 LPC" rev 0x00: 14318179 Hz timer,
watchdog
isa0 at tcpcib0
isadma0 at isa0
com0 at isa0 port 0x3f8/8 irq 4: ti16750, 64 byte fifo
com0: console
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
mtrr: Pentium Pro MTRR support
vscsi0 at root
scsibus1 at vscsi0: 256 targets
softraid0 at root
scsibus2 at softraid0: 256 targets
root on sd0a (a5c639a44063ad4f.a) swap on sd0b dump on sd0b
usbdevs:
Controller /dev/usb0:
addr 1: high speed, self powered, config 1, EHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
port 2 powered
port 3 powered
Controller /dev/usb1:
addr 1: high speed, self powered, config 1, EHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
port 2 powered
port 3 powered
Controller /dev/usb2:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
Controller /dev/usb3:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
Controller /dev/usb4:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
Controller /dev/usb5:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
Controller /dev/usb6:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
Controller /dev/usb7:
addr 1: full speed, self powered, config 1, OHCI root hub(0x0000),
Intel(0x8086), rev 1.00
port 1 powered
