safmq

#include <stdio.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include <fcntl.h> #include <errno.h> #include <sys/ipc.h> #include <sys/shm.h> #include <sys/sem.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/time.h> #include "uuidgen.h" struct shmuuid { unsigned char shm_mac[6]; struct timeval timestamp; unsigned short clock_seq; }; static struct sembuf _lockop = { 0, -1, 0}; static struct sembuf _unlockop = { 0, 1, 0}; /* compares two timestamps */ static int tscomp(const struct timeval* lhs, const struct timeval* rhs); /* retreives the semaphore */ static int getsem(key_t key); /* releases the semaphore */ static void releasesem(int sem); /* retreives the shared memory */ static struct shmuuid* getsharedmem(key_t shmkey); /* releases the shared memory */ static void releaseshm(struct shmuuid* shared); static void getmac(unsigned char mac[6]); static key_t getshmkey(); void uuidgen(struct uuid* puuid) { key_t shmkey; int shmseg; int sem; shmkey = getshmkey(); sem = getsem(shmkey); if (sem != -1) { struct shmuuid* shared = getsharedmem(shmkey); if (shared != (struct shmuuid*)-1) { struct timeval now; int cmp; gettimeofday(&now, NULL); if (tscomp(&(shared->timestamp),&now)) { //srand(shared->timestamp.tv_usec); srand(shared->clock_seq); shared->clock_seq = (unsigned short)rand(); memcpy(&shared->timestamp,&now,sizeof(now)); } else shared->clock_seq++; // takes bottom 12 bits of tv_sec puuid->guid.d1 = ((shared->timestamp.tv_sec<<28)&0xF0000000)|((shared->timestamp.tv_usec<<8)&0x0FFFFFFF); // takes bottom 16 of top 20 puuid->guid.d2 = (unsigned short)(((shared->timestamp.tv_sec>>4) & 0x00FFFF)); // takes top 4 of top 16 puuid->guid.d3 = (unsigned short)(((shared->timestamp.tv_sec>>16) & 0x00FF00) | 0x01); memcpy(&(puuid->guid.d4), &(shared->clock_seq), 2); puuid->guid.d4[0] = (puuid->guid.d4[0] | 0x80) & 0x9F; memcpy((puuid->guid.d4)+2, shared->shm_mac, 6); releaseshm(shared); } else perror("getting shared memory"); releasesem(sem); } else perror("getting semaphore"); } static key_t getshmkey() { static const char path[] = "/tmp/uuid"; int fd = open(path, O_CREAT, 0666); if (fd > 0) { close(fd); return ftok(path, 0); } return ftok("/", 999); } /* Gets and locks the semaphore */ static int getsem(key_t key) { int sem = semget(key, 1, IPC_CREAT | IPC_EXCL); if (sem == -1 && errno == EEXIST) { sem = semget(key, 1, 0); if (sem == -1) return -1; semop(sem, &_lockop, 1); return sem; } else if (sem == -1) { return -1; } semctl(sem, 0, SETVAL, (int)0); return sem; } static void releasesem(int sem) { semop(sem, &_unlockop, 1); } static struct shmuuid* getsharedmem(key_t shmkey) { int seg; struct shmuuid* pmem; seg = shmget(shmkey, sizeof(struct shmuuid), IPC_CREAT|IPC_EXCL|0666); if (seg == -1 && errno == EEXIST) { seg = shmget(shmkey, sizeof(struct shmuuid), 0666); if (seg == -1) return (struct shmuuid*)-1; return (struct shmuuid*)shmat(seg, NULL, 0); } pmem = (struct shmuuid*)shmat(seg, NULL, 0); if (pmem != (struct shmuuid*)-1) { memset(pmem,0,sizeof(struct shmuuid)); getmac(pmem->shm_mac); } return pmem; } static void releaseshm(struct shmuuid* shared) { shmdt(shared); } #ifdef linux #include <sys/ioctl.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <linux/if.h> #endif #ifdef HPUX #include <netio.h> #endif #ifdef AIX #include <sys/ndd_var.h> #include <sys/kinfo.h> #endif static long mac_addr_sys ( u_char *addr) { /* implementation for Linux */ #ifdef linux struct ifreq ifr; struct ifreq *IFR; struct ifconf ifc; char buf[1024]; int s, i; int ok = 0; s = socket(AF_INET, SOCK_DGRAM, 0); if (s==-1) { return -1; } ifc.ifc_len = sizeof(buf); ifc.ifc_buf = buf; ioctl(s, SIOCGIFCONF, &ifc); IFR = ifc.ifc_req; for (i = ifc.ifc_len / sizeof(struct ifreq); --i >= 0; IFR++) { strcpy(ifr.ifr_name, IFR->ifr_name); if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) { if (! (ifr.ifr_flags & IFF_LOOPBACK)) { if (ioctl(s, SIOCGIFHWADDR, &ifr) == 0) { ok = 1; break; } } } } close(s); if (ok) { bcopy( ifr.ifr_hwaddr.sa_data, addr, 6); } else { return -1; } return 0; #endif /* implementation for HP-UX */ #ifdef HPUX #define LAN_DEV0 "/dev/lan0" int fd; struct fis iocnt_block; int i; char net_buf[sizeof(LAN_DEV0)+1]; char *p; (void)sprintf(net_buf, "%s", LAN_DEV0); p = net_buf + strlen(net_buf) - 1; /* * Get 802.3 address from card by opening the driver and interrogating it. */ for (i = 0; i < 10; i++, (*p)++) { if ((fd = open (net_buf, O_RDONLY)) != -1) { iocnt_block.reqtype = LOCAL_ADDRESS; ioctl (fd, NETSTAT, &iocnt_block); close (fd); if (iocnt_block.vtype == 6) break; } } if (fd == -1 || iocnt_block.vtype != 6) { return -1; } bcopy( &iocnt_block.value.s[0], addr, 6); return 0; #endif /* HPUX */ /* implementation for AIX */ #ifdef AIX int size; struct kinfo_ndd *nddp; size = getkerninfo(KINFO_NDD, 0, 0, 0); if (size <= 0) { return -1; } nddp = (struct kinfo_ndd *)malloc(size); if (!nddp) { return -1; } if (getkerninfo(KINFO_NDD, nddp, &size, 0) < 0) { free(nddp); return -1; } bcopy(nddp->ndd_addr, addr, 6); free(nddp); return 0; #endif /* Not implemented platforms */ return -1; } static void getmac(unsigned char mac[6]) { // TODO: Get the mac address int iret = mac_addr_sys(mac); if (iret) memset(mac,1,sizeof(mac)); } static int tscomp(const struct timeval* lhs, const struct timeval* rhs) { int ret; ret = lhs->tv_sec - rhs->tv_sec; if (!ret) ret = lhs->tv_usec - rhs->tv_usec; return ret; } static void rmshm(int shmid) { printf("removeing shared memory for shmid:%ld\n", shmid); if (shmid != -1) { if (shmctl(shmid, IPC_RMID, 0) == -1) perror("removing shared memory"); } } #if 0 int main(int argc, char* argv[]) { struct uuid Uuid = {0}; int x; if (argc > 1 && strcmp(argv[1], "clear")==0) rmshm(shmget(getshmkey(), sizeof(struct shmuuid), 0)); while (98751) { uuidgen(&Uuid); printf("%08lx-%04lx-%04lx-%04lx-%02lx%02lx%02lx%02lx%02lx%02lx\n", Uuid.guid.d1,Uuid.guid.d2,Uuid.guid.d3, *(unsigned short*)Uuid.guid.d4,Uuid.guid.d4[2],Uuid.guid.d4[3], Uuid.guid.d4[4],Uuid.guid.d4[5],Uuid.guid.d4[6],Uuid.guid.d4[7]); } return 0; } #endif