1: #define PETSC_DESIRE_FEATURE_TEST_MACROS /* for getdomainname() */
  2: /*
  3:       Code for manipulating files.
  4: */
  5: #include <petscsys.h>
  6: #if defined(PETSC_HAVE_SYS_UTSNAME_H)
  7:   #include <sys/utsname.h>
  8: #endif
  9: #if defined(PETSC_HAVE_WINDOWS_H)
 10:   #include <windows.h>
 11: #endif
 12: #if defined(PETSC_HAVE_SYS_SYSTEMINFO_H)
 13:   #include <sys/systeminfo.h>
 14: #endif
 15: #if defined(PETSC_HAVE_UNISTD_H)
 16:   #include <unistd.h>
 17: #endif
 18: #if defined(PETSC_HAVE_NETDB_H)
 19:   #include <netdb.h>
 20: #endif
 21: #include <errno.h>

 23: /*@C
 24:   PetscGetHostName - Returns the name of the host. This attempts to
 25:   return the entire Internet name. It may not return the same name
 26:   as `MPI_Get_processor_name()`.

 28:   Not Collective

 30:   Input Parameter:
 31: . nlen - length of name

 33:   Output Parameter:
 34: . name - contains host name.  Must be long enough to hold the name
 35:            This is the fully qualified name, including the domain.

 37:   Level: developer

 39:   Fortran Note:
 40: .vb
 41:   character*(128) name
 42:   call PetscGetHostName(name,ierr)
 43: .ve

 45: .seealso: `PetscGetUserName()`, `PetscGetArchType()`
 46: @*/
 47: PetscErrorCode PetscGetHostName(char name[], size_t nlen)
 48: {
 49:   char *domain = NULL;
 50: #if defined(PETSC_HAVE_UNAME) && !defined(PETSC_HAVE_GETCOMPUTERNAME)
 51:   struct utsname utname;
 52: #endif

 54:   PetscFunctionBegin;
 55: #if defined(PETSC_HAVE_GETCOMPUTERNAME)
 56:   {
 57:     size_t nnlen = nlen;

 59:     GetComputerName((LPTSTR)name, (LPDWORD)(&nnlen));
 60:   }
 61: #elif defined(PETSC_HAVE_UNAME)
 62:   // According to IEEE Std 1003.1-1988 ("POSIX.1") and 1003.1-2024, upon successful completion, uname returns
 63:   // a non-negative value. Otherwise, -1 shall be returned and errno set to indicate the error.
 64:   PetscCheck(uname(&utname) != -1, PETSC_COMM_SELF, PETSC_ERR_SYS, "uname() due to \"%s\"", strerror(errno));
 65:   PetscCall(PetscStrncpy(name, utname.nodename, nlen));
 66: #elif defined(PETSC_HAVE_GETHOSTNAME)
 67:   PetscCheck(!gethostname(name, nlen), PETSC_COMM_SELF, PETSC_ERR_SYS, "gethostname() due to \"%s\"", strerror(errno));
 68: #endif
 69:   /* if there was not enough room then system call will not null terminate name */
 70:   name[nlen - 1] = 0;

 72:   /* See if this name includes the domain */
 73:   PetscCall(PetscStrchr(name, '.', &domain));
 74:   if (!domain) {
 75:     size_t l, ll;

 77:     PetscCall(PetscStrlen(name, &l));
 78:     if (l == nlen - 1) PetscFunctionReturn(PETSC_SUCCESS);
 79:     name[l++] = '.';
 80:     name[l]   = 0;
 81: #if defined(PETSC_HAVE_GETDOMAINNAME)
 82:     PetscCheck(!getdomainname(name + l, (int)(nlen - l)), PETSC_COMM_SELF, PETSC_ERR_SYS, "getdomainname() due to \"%s\"", strerror(errno));
 83: #endif
 84:     /* check if domain name is not a dnsdomainname and nuke it */
 85:     PetscCall(PetscStrlen(name, &ll));
 86:     if (ll > 4) {
 87:       const char *suffixes[] = {".edu", ".com", ".net", ".org", ".mil", NULL};
 88:       PetscInt    index;

 90:       PetscCall(PetscStrendswithwhich(name, suffixes, &index));
 91:       if (!suffixes[index]) {
 92:         PetscCall(PetscInfo(NULL, "Rejecting domainname, likely is NIS %s\n", name));
 93:         name[l - 1] = 0;
 94:       }
 95:     }
 96:   }
 97:   PetscFunctionReturn(PETSC_SUCCESS);
 98: }