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Diffstat (limited to 'src/os.c')
| -rw-r--r-- | src/os.c | 971 |
1 files changed, 971 insertions, 0 deletions
diff --git a/src/os.c b/src/os.c new file mode 100644 index 0000000..ac5f61b --- /dev/null +++ b/src/os.c @@ -0,0 +1,971 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) The Exim Maintainers 2021 - 2022 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ +/* See the file NOTICE for conditions of use and distribution. */ + +#ifdef STAND_ALONE +# include <signal.h> +# include <stdio.h> +# include <time.h> +#endif + +#ifndef CS +# define CS (char *) +# define US (unsigned char *) +#endif + +/* This source file contains "default" system-dependent functions which +provide functionality (or lack of it) in cases where the OS-specific os.c +file has not. Some of them are tailored by macros defined in os.h files. */ + + +#ifndef OS_RESTARTING_SIGNAL +/************************************************* +* Set up restarting signal * +*************************************************/ + +/* This function has the same functionality as the ANSI C signal() function, +except that it arranges that, if the signal happens during a system call, the +system call gets restarted. (Also, it doesn't return a result.) Different +versions of Unix have different defaults, and different ways of setting up a +restarting signal handler. If the functionality is not available, the signal +should be set to be ignored. This function is used only for catching SIGUSR1. +*/ + +void +os_restarting_signal(int sig, void (*handler)(int)) +{ +/* Many systems have the SA_RESTART sigaction for specifying that a signal +should restart system calls. These include SunOS5, AIX, BSDI, IRIX, FreeBSD, +OSF1, Linux and HP-UX 10 (but *not* HP-UX 9). */ + +#ifdef SA_RESTART +struct sigaction act; +act.sa_handler = handler; +sigemptyset(&(act.sa_mask)); +act.sa_flags = SA_RESTART; +sigaction(sig, &act, NULL); + +#ifdef STAND_ALONE +printf("Used SA_RESTART\n"); +#endif + +/* SunOS4 and Ultrix default to non-interruptable signals, with SV_INTERRUPT +for making them interruptable. This seems to be a dying fashion. */ + +#elif defined SV_INTERRUPT +signal(sig, handler); + +#ifdef STAND_ALONE +printf("Used default signal()\n"); +#endif + + +/* If neither SA_RESTART nor SV_INTERRUPT is available we don't know how to +set up a restarting signal, so simply suppress the facility. */ + +#else +signal(sig, SIG_IGN); + +#ifdef STAND_ALONE +printf("Used SIG_IGN\n"); +#endif + +#endif +} + +#endif /* OS_RESTARTING_SIGNAL */ + + +#ifndef OS_NON_RESTARTING_SIGNAL +/************************************************* +* Set up non-restarting signal * +*************************************************/ + +/* This function has the same functionality as the ANSI C signal() function, +except that it arranges that, if the signal happens during a system call, the +system call gets interrupted. (Also, it doesn't return a result.) Different +versions of Unix have different defaults, and different ways of setting up a +non-restarting signal handler. For systems for which we don't know what to do, +just use the normal signal() function and hope for the best. */ + +void +os_non_restarting_signal(int sig, void (*handler)(int)) +{ +/* Many systems have the SA_RESTART sigaction for specifying that a signal +should restart system calls. These include SunOS5, AIX, BSDI, IRIX, FreeBSD, +OSF1, Linux and HP-UX 10 (but *not* HP-UX 9). */ + +#ifdef SA_RESTART +struct sigaction act; +act.sa_handler = handler; +sigemptyset(&(act.sa_mask)); +act.sa_flags = 0; +sigaction(sig, &act, NULL); + +#ifdef STAND_ALONE +printf("Used sigaction() with flags = 0\n"); +#endif + +/* SunOS4 and Ultrix default to non-interruptable signals, with SV_INTERRUPT +for making them interruptable. This seems to be a dying fashion. */ + +#elif defined SV_INTERRUPT +struct sigvec sv; +sv.sv_handler = handler; +sv.sv_flags = SV_INTERRUPT; +sv.sv_mask = -1; +sigvec(sig, &sv, NULL); + +#ifdef STAND_ALONE +printf("Used sigvec() with flags = SV_INTERRUPT\n"); +#endif + +/* If neither SA_RESTART nor SV_INTERRUPT is available we don't know how to +set up a restarting signal, so just use the standard signal() function. */ + +#else +signal(sig, handler); + +#ifdef STAND_ALONE +printf("Used default signal()\n"); +#endif + +#endif +} + +#endif /* OS_NON_RESTARTING_SIGNAL */ + + + +#ifdef STRERROR_FROM_ERRLIST +/************************************************* +* Provide strerror() for non-ANSI libraries * +*************************************************/ + +/* Some old-fashioned systems still around (e.g. SunOS4) don't have strerror() +in their libraries, but can provide the same facility by this simple +alternative function. */ + +char * +strerror(int n) +{ +if (n < 0 || n >= sys_nerr) return "unknown error number"; +return sys_errlist[n]; +} +#endif /* STRERROR_FROM_ERRLIST */ + + + +#ifndef OS_STRSIGNAL +/************************************************* +* Provide strsignal() for systems without * +*************************************************/ + +/* Some systems have strsignal() to turn signal numbers into names; others +may have other means of doing this. This function is used for those systems +that have nothing. It provides a basic translation for the common standard +signal numbers. I've been extra cautious with the ifdef's here. Probably more +than is necessary... */ + +const char * +os_strsignal(const int n) +{ +switch (n) + { + #ifdef SIGHUP + case SIGHUP: return "hangup"; + #endif + + #ifdef SIGINT + case SIGINT: return "interrupt"; + #endif + + #ifdef SIGQUIT + case SIGQUIT: return "quit"; + #endif + + #ifdef SIGILL + case SIGILL: return "illegal instruction"; + #endif + + #ifdef SIGTRAP + case SIGTRAP: return "trace trap"; + #endif + + #ifdef SIGABRT + case SIGABRT: return "abort"; + #endif + + #ifdef SIGEMT + case SIGEMT: return "EMT instruction"; + #endif + + #ifdef SIGFPE + case SIGFPE: return "arithmetic exception"; + #endif + + #ifdef SIGKILL + case SIGKILL: return "killed"; + #endif + + #ifdef SIGBUS + case SIGBUS: return "bus error"; + #endif + + #ifdef SIGSEGV + case SIGSEGV: return "segmentation fault"; + #endif + + #ifdef SIGSYS + case SIGSYS: return "bad system call"; + #endif + + #ifdef SIGPIPE + case SIGPIPE: return "broken pipe"; + #endif + + #ifdef SIGALRM + case SIGALRM: return "alarm"; + #endif + + #ifdef SIGTERM + case SIGTERM: return "terminated"; + #endif + + #ifdef SIGUSR1 + case SIGUSR1: return "user signal 1"; + #endif + + #ifdef SIGUSR2 + case SIGUSR2: return "user signal 2"; + #endif + + #ifdef SIGCHLD + case SIGCHLD: return "child stop or exit"; + #endif + + #ifdef SIGPWR + case SIGPWR: return "power fail/restart"; + #endif + + #ifdef SIGURG + case SIGURG: return "urgent condition on I/O channel"; + #endif + + #ifdef SIGSTOP + case SIGSTOP: return "stop"; + #endif + + #ifdef SIGTSTP + case SIGTSTP: return "stop from tty"; + #endif + + #ifdef SIGXCPU + case SIGXCPU: return "exceeded CPU limit"; + #endif + + #ifdef SIGXFSZ + case SIGXFSZ: return "exceeded file size limit"; + #endif + + default: return "unrecognized signal number"; + } +} +#endif /* OS_STRSIGNAL */ + + + +#ifndef OS_STREXIT +/************************************************* +* Provide strexit() for systems without * +*************************************************/ + +/* Actually, I don't know of any system that has a strexit() function to turn +exit codes into text, but this function is implemented this way so that if any +OS does have such a thing, it could be used instead of this build-in one. */ + +const char * +os_strexit(const int n) +{ +switch (n) + { + /* On systems without sysexits.h we can assume only those exit codes + that are given a default value in exim.h. */ + + #ifndef NO_SYSEXITS + case EX_USAGE: return "(could mean usage or syntax error)"; + case EX_DATAERR: return "(could mean error in input data)"; + case EX_NOINPUT: return "(could mean input data missing)"; + case EX_NOUSER: return "(could mean user nonexistent)"; + case EX_NOHOST: return "(could mean host nonexistent)"; + case EX_SOFTWARE: return "(could mean internal software error)"; + case EX_OSERR: return "(could mean internal operating system error)"; + case EX_OSFILE: return "(could mean system file missing)"; + case EX_IOERR: return "(could mean input/output error)"; + case EX_PROTOCOL: return "(could mean protocol error)"; + case EX_NOPERM: return "(could mean permission denied)"; + #endif + + case EX_EXECFAILED: return "(could mean unable to exec or command does not exist)"; + case EX_UNAVAILABLE: return "(could mean service or program unavailable)"; + case EX_CANTCREAT: return "(could mean can't create output file)"; + case EX_TEMPFAIL: return "(could mean temporary error)"; + case EX_CONFIG: return "(could mean configuration error)"; + default: return ""; + } +} +#endif /* OS_STREXIT */ + + + + +/*********************************************************** +* Load average function * +***********************************************************/ + +/* Although every Unix seems to have a different way of getting the load +average, a number of them have things in common. Some common variants are +provided below, but if an OS has unique requirements it can be handled in +a specific os.c file. What is required is a function called os_getloadavg +which takes no arguments and passes back the load average * 1000 as an int, +or -1 if no data is available. */ + + +/* ----------------------------------------------------------------------- */ +/* If the OS has got a BSD getloadavg() function, life is very easy. */ + +#if !defined(OS_LOAD_AVERAGE) && defined(HAVE_BSD_GETLOADAVG) +#define OS_LOAD_AVERAGE + +int +os_getloadavg(void) +{ +double avg; +int loads = getloadavg (&avg, 1); +if (loads != 1) return -1; +return (int)(avg * 1000.0); +} +#endif +/* ----------------------------------------------------------------------- */ + + + +/* ----------------------------------------------------------------------- */ +/* Only SunOS5 has the kstat functions as far as I know, but put the code +here as there is the -hal variant, and other systems might follow this road one +day. */ + +#if !defined(OS_LOAD_AVERAGE) && defined(HAVE_KSTAT) +#define OS_LOAD_AVERAGE + +#include <kstat.h> + +int +os_getloadavg(void) +{ +int avg; +kstat_ctl_t *kc; +kstat_t *ksp; +kstat_named_t *kn; + +if ((kc = kstat_open()) == NULL || + (ksp = kstat_lookup(kc, LOAD_AVG_KSTAT_MODULE, 0, LOAD_AVG_KSTAT)) + == NULL || + kstat_read(kc, ksp, NULL) < 0 || + (kn = kstat_data_lookup(ksp, LOAD_AVG_SYMBOL)) == NULL) + return -1; + +avg = (int)(((double)(kn->LOAD_AVG_FIELD)/FSCALE) * 1000.0); + +kstat_close(kc); +return avg; +} + +#endif +/* ----------------------------------------------------------------------- */ + + + +/* ----------------------------------------------------------------------- */ +/* Handle OS where a kernel symbol has to be read from /dev/kmem */ + +#if !defined(OS_LOAD_AVERAGE) && defined(HAVE_DEV_KMEM) +#define OS_LOAD_AVERAGE + +#include <nlist.h> + +static int avg_kd = -1; +static long avg_offset; + +int +os_getloadavg(void) +{ +LOAD_AVG_TYPE avg; + +if (avg_kd < 0) + { + struct nlist nl[2]; + nl[0].n_name = LOAD_AVG_SYMBOL; + nl[1].n_name = ""; + nlist (KERNEL_PATH, nl); + avg_offset = (long)nl[0].n_value; + avg_kd = open ("/dev/kmem", 0); + if (avg_kd < 0) return -1; + (void) fcntl(avg_kd, F_SETFD, FD_CLOEXEC); + } + +if (lseek (avg_kd, avg_offset, 0) == -1L + || read (avg_kd, CS (&avg), sizeof (avg)) != sizeof(avg)) + return -1; + +return (int)(((double)avg/FSCALE)*1000.0); +} + +#endif +/* ----------------------------------------------------------------------- */ + + + +/* ----------------------------------------------------------------------- */ +/* If nothing is known about this OS, then the load average facility is +not available. */ + +#ifndef OS_LOAD_AVERAGE + +int +os_getloadavg(void) +{ +return -1; +} + +#endif + +/* ----------------------------------------------------------------------- */ + + + +#if !defined FIND_RUNNING_INTERFACES +/************************************************* +* Find all the running network interfaces * +*************************************************/ + +/* Finding all the running interfaces is something that has os-dependent +tweaks, even in the IPv4 case, and it gets worse for IPv6, which is why this +code is now in the os-dependent source file. There is a common function which +works on most OS (except IRIX) for IPv4 interfaces, and, with some variations +controlled by macros, on at least one OS for IPv6 and IPv4 interfaces. On Linux +with IPv6, the common function is used for the IPv4 interfaces and additional +code used for IPv6. Consequently, the real function is called +os_common_find_running_interfaces() so that it can be called from the Linux +function. On non-Linux systems, the macro for os_find_running_interfaces just +calls the common function; on Linux it calls the Linux function. + +This function finds the addresses of all the running interfaces on the machine. +A chain of blocks containing the textual form of the addresses is returned. + +getifaddrs() provides a sane consistent way to query this on modern OSs, +otherwise fall back to a maze of twisty ioctl() calls + +Arguments: none +Returns: a chain of ip_address_items, each pointing to a textual + version of an IP address, with the port field set to zero +*/ + + +#ifndef NO_FIND_INTERFACES + +#ifdef HAVE_GETIFADDRS + +#include <ifaddrs.h> + +ip_address_item * +os_common_find_running_interfaces(void) +{ +struct ifaddrs *ifalist = NULL; +ip_address_item *yield = NULL; +ip_address_item *last = NULL; +ip_address_item *next; + +if (getifaddrs(&ifalist) != 0) + log_write(0, LOG_PANIC_DIE, "Unable to call getifaddrs: %d %s", + errno, strerror(errno)); + +for (struct ifaddrs * ifa = ifalist; ifa; ifa = ifa->ifa_next) + { + struct sockaddr * ifa_addr = ifa->ifa_addr; + if (!ifa_addr) continue; + if (ifa_addr->sa_family != AF_INET +#if HAVE_IPV6 + && ifa_addr->sa_family != AF_INET6 +#endif /* HAVE_IPV6 */ + ) + continue; + + if ( !(ifa->ifa_flags & IFF_UP) ) /* Only want 'UP' interfaces */ + continue; + + /* Create a data block for the address, fill in the data, and put it on the + chain. */ + + next = store_get(sizeof(ip_address_item), GET_UNTAINTED); + next->next = NULL; + next->port = 0; + (void)host_ntoa(-1, ifa_addr, next->address, NULL); + + if (!yield) + yield = last = next; + else + { + last->next = next; + last = next; + } + + DEBUG(D_interface) debug_printf("Actual local interface address is %s (%s)\n", + last->address, ifa->ifa_name); + } + +/* free the list of addresses, and return the chain of data blocks. */ + +freeifaddrs (ifalist); +return yield; +} + +#else /* HAVE_GETIFADDRS */ + +/* +Problems: + + (1) Solaris 2 has the SIOGIFNUM call to get the number of interfaces, but + other OS (including Solaris 1) appear not to. So just screw in a largeish + fixed number, defined by MAX_INTERFACES. This is in the config.h file and + can be changed in Local/Makefile. Unfortunately, the www addressing scheme + means that some hosts have a very large number of virtual interfaces. Such + hosts are recommended to set local_interfaces to avoid problems with this. + + (2) If the standard code is run on IRIX, it does not return any alias + interfaces. There is special purpose code for that operating system, which + uses the sysctl() function. The code is in OS/os.c-IRIX, and this code isn't + used on that OS. + + (3) Some experimental/developing OS (e.g. GNU/Hurd) do not have any means + of finding the interfaces. If NO_FIND_INTERFACES is set, a fudge-up is used + instead. + + (4) Some operating systems set the IP address in what SIOCGIFCONF returns; + others do not, and require SIOCGIFADDR to be called to get it. For most of + the former, calling the latter does no harm, but it causes grief on Linux and + BSD systems in the case of IP aliasing, so a means of cutting it out is + provided. +*/ + +/* If there is IPv6 support, and SIOCGLIFCONF is defined, define macros to +use these new, longer versions of the old IPv4 interfaces. Otherwise, define +the macros to use the historical versions. */ + +#if HAVE_IPV6 && defined SIOCGLIFCONF +#define V_ifconf lifconf +#define V_ifreq lifreq +#define V_GIFADDR SIOCGLIFADDR +#define V_GIFCONF SIOCGLIFCONF +#define V_GIFFLAGS SIOCGLIFFLAGS +#define V_ifc_buf lifc_buf +#define V_ifc_family lifc_family +#define V_ifc_flags lifc_flags +#define V_ifc_len lifc_len +#define V_ifr_addr lifr_addr +#define V_ifr_flags lifr_flags +#define V_ifr_name lifr_name +#define V_FAMILY_QUERY AF_UNSPEC +#define V_family ss_family +#else +#define V_ifconf ifconf +#define V_ifreq ifreq +#define V_GIFADDR SIOCGIFADDR +#define V_GIFCONF SIOCGIFCONF +#define V_GIFFLAGS SIOCGIFFLAGS +#define V_ifc_buf ifc_buf +#define V_ifc_family ifc_family +#define V_ifc_flags ifc_flags +#define V_ifc_len ifc_len +#define V_ifr_addr ifr_addr +#define V_ifr_flags ifr_flags +#define V_ifr_name ifr_name +#define V_family sa_family +#endif + +/* In all cases of IPv6 support, use an IPv6 socket. Otherwise (at least on +Solaris 8) the call to read the flags doesn't work for IPv6 interfaces. If +we find we can't actually make an IPv6 socket, the code will revert to trying +an IPv4 socket. */ + +#if HAVE_IPV6 +#define FAMILY AF_INET6 +#else +#define FAMILY AF_INET +#endif + +/* OK, after all that preliminary stuff, here's the code. */ + +ip_address_item * +os_common_find_running_interfaces(void) +{ +struct V_ifconf ifc; +struct V_ifreq ifreq; +int vs; +ip_address_item *yield = NULL; +ip_address_item *last = NULL; +ip_address_item *next; +char buf[MAX_INTERFACES*sizeof(struct V_ifreq)]; +struct sockaddr *addrp; +size_t len = 0; +char addrbuf[512]; + +/* We have to create a socket in order to do ioctls on it to find out +what we want to know. */ + +if ((vs = socket(FAMILY, SOCK_DGRAM, 0)) < 0) + { + #if HAVE_IPV6 + DEBUG(D_interface) + debug_printf("Unable to create IPv6 socket to find interface addresses:\n " + "error %d %s\nTrying for an IPv4 socket\n", errno, strerror(errno)); + vs = socket(AF_INET, SOCK_DGRAM, 0); + if (vs < 0) + #endif + log_write(0, LOG_PANIC_DIE, "Unable to create IPv4 socket to find interface " + "addresses: %d %s", errno, strerror(errno)); + } + +/* Get the interface configuration. Some additional data is required when the +new structures are in use. */ + +ifc.V_ifc_len = sizeof(buf); +ifc.V_ifc_buf = buf; + +#ifdef V_FAMILY_QUERY +ifc.V_ifc_family = V_FAMILY_QUERY; +ifc.V_ifc_flags = 0; +#endif + +if (ioctl(vs, V_GIFCONF, CS &ifc) < 0) + log_write(0, LOG_PANIC_DIE, "Unable to get interface configuration: %d %s", + errno, strerror(errno)); + +/* If the buffer is big enough, the ioctl sets the value of ifc.V_ifc_len to +the amount actually used. If the buffer isn't big enough, at least on some +operating systems, ifc.V_ifc_len still gets set to correspond to the total +number of interfaces, even though they don't all fit in the buffer. */ + +if (ifc.V_ifc_len > sizeof(buf)) + { + ifc.V_ifc_len = sizeof(buf); + DEBUG(D_interface) + debug_printf("more than %d interfaces found: remainder not used\n" + "(set MAX_INTERFACES in Local/Makefile and rebuild if you want more)\n", + MAX_INTERFACES); + } + +/* For each interface, check it is an IP interface, get its flags, and see if +it is up; if not, skip. + +BSD systems differ from others in what SIOCGIFCONF returns. Other systems +return a vector of ifreq structures whose size is as defined by the structure. +BSD systems allow sockaddrs to be longer than their sizeof, which in turn makes +the ifreq structures longer than their sizeof. The code below has its origins +in amd and ifconfig; it uses the sa_len field of each sockaddr to determine +each item's length. + +This is complicated by the fact that, at least on BSD systems, the data in the +buffer is not guaranteed to be aligned. Thus, we must first copy the basic +struct to some aligned memory before looking at the field in the fixed part to +find its length, and then recopy the correct length. */ + +for (char * cp = buf; cp < buf + ifc.V_ifc_len; cp += len) + { + memcpy(CS &ifreq, cp, sizeof(ifreq)); + + #ifndef HAVE_SA_LEN + len = sizeof(struct V_ifreq); + + #else + len = ((ifreq.ifr_addr.sa_len > sizeof(ifreq.ifr_addr))? + ifreq.ifr_addr.sa_len : sizeof(ifreq.ifr_addr)) + + sizeof(ifreq.V_ifr_name); + if (len > sizeof(addrbuf)) + log_write(0, LOG_PANIC_DIE, "Address for %s interface is absurdly long", + ifreq.V_ifr_name); + + #endif + + /* If not an IP interface, skip */ + + if (ifreq.V_ifr_addr.V_family != AF_INET + #if HAVE_IPV6 + && ifreq.V_ifr_addr.V_family != AF_INET6 + #endif + ) continue; + + /* Get the interface flags, and if the interface is down, continue. Formerly, + we treated the inability to get the flags as a panic-die error. However, it + seems that on some OS (Solaris 9 being the case noted), it is possible to + have an interface in this list for which this call fails because the + interface hasn't been "plumbed" to any protocol (IPv4 or IPv6). Therefore, + we now just treat this case as "down" as well. */ + + if (ioctl(vs, V_GIFFLAGS, CS &ifreq) < 0) + { + continue; + /************* + log_write(0, LOG_PANIC_DIE, "Unable to get flags for %s interface: %d %s", + ifreq.V_ifr_name, errno, strerror(errno)); + *************/ + } + if ((ifreq.V_ifr_flags & IFF_UP) == 0) continue; + + /* On some operating systems we have to get the IP address of the interface + by another call. On others, it's already there, but we must copy the full + length because we only copied the basic length above, and anyway, + GIFFLAGS may have wrecked the data. */ + + #ifndef SIOCGIFCONF_GIVES_ADDR + if (ioctl(vs, V_GIFADDR, CS &ifreq) < 0) + log_write(0, LOG_PANIC_DIE, "Unable to get IP address for %s interface: " + "%d %s", ifreq.V_ifr_name, errno, strerror(errno)); + addrp = &ifreq.V_ifr_addr; + + #else + memcpy(addrbuf, cp + offsetof(struct V_ifreq, V_ifr_addr), + len - sizeof(ifreq.V_ifr_name)); + addrp = (struct sockaddr *)addrbuf; + #endif + + /* Create a data block for the address, fill in the data, and put it on the + chain. */ + + next = store_get(sizeof(ip_address_item), GET_UNTAINTED); + next->next = NULL; + next->port = 0; + (void)host_ntoa(-1, addrp, next->address, NULL); + + if (yield == NULL) yield = last = next; else + { + last->next = next; + last = next; + } + + DEBUG(D_interface) debug_printf("Actual local interface address is %s (%s)\n", + last->address, ifreq.V_ifr_name); + } + +/* Close the socket, and return the chain of data blocks. */ + +(void)close(vs); +return yield; +} + +#endif /* HAVE_GETIFADDRS */ + +#else /* NO_FIND_INTERFACES */ + +/* Some experimental or developing OS (e.g. GNU/Hurd) do not have the ioctls, +and there is no other way to get a list of the (IP addresses of) local +interfaces. We just return the loopback address(es). */ + +ip_address_item * +os_common_find_running_interfaces(void) +{ +ip_address_item *yield = store_get(sizeof(address_item), GET_UNTAINTED); +yield->address = US"127.0.0.1"; +yield->port = 0; +yield->next = NULL; + +#if HAVE_IPV6 +yield->next = store_get(sizeof(address_item), GET_UNTAINTED); +yield->next->address = US"::1"; +yield->next->port = 0; +yield->next->next = NULL; +#endif + +DEBUG(D_interface) debug_printf("Unable to find local interface addresses " + "on this OS: returning loopback address(es)\n"); +return yield; +} + +#endif /* NO_FIND_INTERFACES */ +#endif /* FIND_RUNNING_INTERFACES */ + + + + +/* ----------------------------------------------------------------------- */ + +/*********************************************************** +* DNS Resolver Base Finder * +***********************************************************/ + +/* We need to be able to set options for the system resolver(5), historically +made available as _res. At least one OS (NetBSD) now no longer provides this +directly, instead making you call a function per thread to get a handle. +Other OSs handle thread-safe resolver differently, in ways which fail if the +programmer creates their own structs. */ + +#if !defined(OS_GET_DNS_RESOLVER_RES) && !defined(COMPILE_UTILITY) + +#include <resolv.h> + +/* confirmed that res_state is typedef'd as a struct* on BSD and Linux, will +find out how unportable it is on other OSes, but most resolver implementations +should be descended from ISC's bind. + +Linux and BSD do: + define _res (*__res_state()) +identically. We just can't rely on __foo functions. It's surprising that use +of _res has been as portable as it has, for so long. + +So, since _res works everywhere, and everything can decode the struct, I'm +going to gamble that res_state is a typedef everywhere and use that as the +return type. +*/ + +res_state +os_get_dns_resolver_res(void) +{ +return &_res; +} + +#endif /* OS_GET_DNS_RESOLVER_RES */ + +/* ----------------------------------------------------------------------- */ + +/*********************************************************** +* unsetenv() * +***********************************************************/ + +/* Most modern systems define int unsetenv(const char*), +* some don't. */ + +#if !defined(OS_UNSETENV) +int +os_unsetenv(const unsigned char * name) +{ +return unsetenv(CS name); +} +#endif + +/* ----------------------------------------------------------------------- */ + +/*********************************************************** +* getcwd() * +***********************************************************/ + +/* Glibc allows getcwd(NULL, 0) to do auto-allocation. Some systems +do auto-allocation, but need the size of the buffer, and others +may not even do this. If the OS supports getcwd(NULL, 0) we'll use +this, for all other systems we provide our own getcwd() */ + +#if !defined(OS_GETCWD) +unsigned char * +os_getcwd(unsigned char * buffer, size_t size) +{ +return US getcwd(CS buffer, size); +} +#else +#ifndef PATH_MAX +# define PATH_MAX 4096 +#endif +unsigned char * +os_getcwd(unsigned char * buffer, size_t size) +{ +char * b = CS buffer; + +if (!size) size = PATH_MAX; +if (!b && !(b = malloc(size))) return NULL; +if (!(b = getcwd(b, size))) return NULL; +return buffer ? buffer : realloc(b, strlen(b) + 1); +} +#endif + +/* ----------------------------------------------------------------------- */ + + + + +/************************************************* +************************************************** +* Stand-alone test program * +************************************************** +*************************************************/ + + +#ifdef STAND_ALONE + +#ifdef CLOCKS_PER_SEC +#define REAL_CLOCK_TICK CLOCKS_PER_SEC +#else + #ifdef CLK_TCK + #define REAL_CLOCK_TICK CLK_TCK + #else + #define REAL_CLOCK_TICK 1000000 /* SunOS4 */ + #endif +#endif + + +int main(int argc, char **argv) +{ +char buffer[128]; +int fd = fileno(stdin); +int rc; + +printf("Testing restarting signal; wait for handler message, then type a line\n"); +strcpy(buffer, "*** default ***\n"); +os_restarting_signal(SIGALRM, sigalrm_handler); +ALARM(2); +if ((rc = read(fd, buffer, sizeof(buffer))) < 0) + printf("No data read\n"); +else + { + buffer[rc] = 0; + printf("Read: %s", buffer); + } +ALARM_CLR(0); + +printf("Testing non-restarting signal; should read no data after handler message\n"); +strcpy(buffer, "*** default ***\n"); +os_non_restarting_signal(SIGALRM, sigalrm_handler); +ALARM(2); +if ((rc = read(fd, buffer, sizeof(buffer))) < 0) + printf("No data read\n"); +else + { + buffer[rc] = 0; + printf("Read: %s", buffer); + } +ALARM_CLR(0); + +printf("Testing load averages (last test - ^C to kill)\n"); +for (;;) + { + int avg; + clock_t used; + clock_t before = clock(); + avg = os_getloadavg(); + used = clock() - before; + printf("cpu time = %.2f ", (double)used/REAL_CLOCK_TICK); + if (avg < 0) + { + printf("load average not available\n"); + break; + } + printf("load average = %.2f\n", (double)avg/1000.0); + sleep(2); + } +return 0; +} + +#endif + +/* End of os.c */ |