| 1 | #include <stdlib.h> |
| 2 | #include <stdio.h> |
| 3 | #include <unistd.h> |
| 4 | #include <string.h> |
| 5 | #include <errno.h> |
| 6 | #include <sys/socket.h> |
| 7 | #include <netinet/in.h> |
| 8 | #include <netdb.h> |
| 9 | #include <arpa/inet.h> |
| 10 | #include <nss.h> |
| 11 | #include <sys/types.h> |
| 12 | #include <fcntl.h> |
| 13 | |
| 14 | enum nss_status _nss_icmp_gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *result, char *buffer, size_t buflen, int *errnop, int *h_errnop) |
| 15 | { |
| 16 | int ret; |
| 17 | struct retstruct { |
| 18 | char *aliaslist[16]; |
| 19 | char *addrlist[2]; |
| 20 | char retaddr[16]; |
| 21 | } *retbuf; |
| 22 | char addrbuf[1024]; |
| 23 | int an; |
| 24 | char *p, *p2, *p3; |
| 25 | u_int8_t *ap; |
| 26 | pid_t child; |
| 27 | int pfd[2]; |
| 28 | int rl; |
| 29 | |
| 30 | retbuf = (struct retstruct *)buffer; |
| 31 | if((buflen < sizeof(*retbuf)) || (len > sizeof(retbuf->retaddr))) { |
| 32 | *errnop = ENOMEM; |
| 33 | *h_errnop = NETDB_INTERNAL; |
| 34 | return(NSS_STATUS_UNAVAIL); |
| 35 | } |
| 36 | |
| 37 | ap = (u_int8_t *)addr; |
| 38 | if(inet_ntop(af, addr, addrbuf, sizeof(addrbuf)) == NULL) { |
| 39 | *errnop = errno; |
| 40 | *h_errnop = NETDB_INTERNAL; |
| 41 | return(NSS_STATUS_UNAVAIL); |
| 42 | } |
| 43 | |
| 44 | if(pipe(pfd)) { |
| 45 | *errnop = errno; |
| 46 | *h_errnop = NETDB_INTERNAL; |
| 47 | return(NSS_STATUS_UNAVAIL); |
| 48 | } |
| 49 | /* I honestly don't know if it is considered OK to fork in other |
| 50 | * people's programs. We need a SUID worker, though, so there's |
| 51 | * little choice that I can see. */ |
| 52 | if((child = fork()) < 0) { |
| 53 | *errnop = errno; |
| 54 | *h_errnop = NETDB_INTERNAL; |
| 55 | return(NSS_STATUS_UNAVAIL); |
| 56 | } |
| 57 | |
| 58 | if(child == 0) { |
| 59 | int i, fd; |
| 60 | |
| 61 | if((fd = open("/dev/null", O_WRONLY)) < 0) |
| 62 | exit(127); |
| 63 | close(pfd[0]); |
| 64 | dup2(pfd[1], 1); |
| 65 | dup2(fd, 2); |
| 66 | for(i = 3; i < FD_SETSIZE; i++) |
| 67 | close(i); |
| 68 | |
| 69 | execlp("idnlookup", "idnlookup", addrbuf, NULL); |
| 70 | exit(127); |
| 71 | } |
| 72 | |
| 73 | close(pfd[1]); |
| 74 | |
| 75 | rl = 0; |
| 76 | do { |
| 77 | ret = read(pfd[0], addrbuf + rl, sizeof(addrbuf) - rl); |
| 78 | if(ret < 0) { |
| 79 | *errnop = errno; |
| 80 | *h_errnop = NETDB_INTERNAL; |
| 81 | close(pfd[0]); |
| 82 | return(NSS_STATUS_UNAVAIL); |
| 83 | } |
| 84 | rl += ret; |
| 85 | if(rl >= sizeof(addrbuf) - 1) { |
| 86 | *errnop = ENOMEM; |
| 87 | *h_errnop = NETDB_INTERNAL; |
| 88 | close(pfd[0]); |
| 89 | return(NSS_STATUS_UNAVAIL); |
| 90 | } |
| 91 | } while(ret != 0); |
| 92 | addrbuf[rl] = 0; |
| 93 | close(pfd[0]); |
| 94 | |
| 95 | an = 0; |
| 96 | p = addrbuf; |
| 97 | p3 = buffer + sizeof(*retbuf); |
| 98 | while((p2 = strchr(p, '\n')) != NULL) { |
| 99 | *p2 = 0; |
| 100 | if((p3 - buffer) + (p2 - p) + 1 > buflen) { |
| 101 | *errnop = ENOMEM; |
| 102 | *h_errnop = NETDB_INTERNAL; |
| 103 | return(NSS_STATUS_UNAVAIL); |
| 104 | } |
| 105 | memcpy(p3, p, (p2 - p) + 1); |
| 106 | retbuf->aliaslist[an] = p3; |
| 107 | p3 += (p2 - p) + 1; |
| 108 | p = p2 + 1; |
| 109 | if(++an == 16) { |
| 110 | *errnop = ENOMEM; |
| 111 | *h_errnop = NETDB_INTERNAL; |
| 112 | return(NSS_STATUS_UNAVAIL); |
| 113 | } |
| 114 | } |
| 115 | if(an == 0) { |
| 116 | *h_errnop = TRY_AGAIN; /* Is this correct? */ |
| 117 | return(NSS_STATUS_NOTFOUND); |
| 118 | } |
| 119 | retbuf->aliaslist[an] = NULL; |
| 120 | |
| 121 | memcpy(retbuf->retaddr, addr, len); |
| 122 | retbuf->addrlist[0] = retbuf->retaddr; |
| 123 | retbuf->addrlist[1] = NULL; |
| 124 | result->h_name = retbuf->aliaslist[0]; |
| 125 | result->h_aliases = retbuf->aliaslist; |
| 126 | result->h_addr_list = retbuf->addrlist; |
| 127 | result->h_addrtype = af; |
| 128 | result->h_length = len; |
| 129 | |
| 130 | *h_errnop = NETDB_SUCCESS; |
| 131 | return(NSS_STATUS_SUCCESS); |
| 132 | } |