diff options
Diffstat (limited to 'source3/smbwrapper/shared.c')
| -rw-r--r-- | source3/smbwrapper/shared.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/source3/smbwrapper/shared.c b/source3/smbwrapper/shared.c new file mode 100644 index 0000000000..00dd30b70e --- /dev/null +++ b/source3/smbwrapper/shared.c @@ -0,0 +1,221 @@ +/* + Unix SMB/CIFS implementation. + SMB wrapper functions - shared variables + Copyright (C) Andrew Tridgell 1998 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "includes.h" + +static int shared_fd; +static char *variables; +static int shared_size; + +/***************************************************** +setup the shared area +*******************************************************/ +void smbw_setup_shared(void) +{ + int fd; + pstring name, s; + + slprintf(name,sizeof(name)-1, "%s/smbw.XXXXXX",tmpdir()); + + fd = smb_mkstemp(name); + + if (fd == -1) goto failed; + + unlink(name); + + shared_fd = set_maxfiles(SMBW_MAX_OPEN); + + while (shared_fd && dup2(fd, shared_fd) != shared_fd) shared_fd--; + + if (shared_fd == 0) goto failed; + + close(fd); + + DEBUG(4,("created shared_fd=%d\n", shared_fd)); + + slprintf(s,sizeof(s)-1,"%d", shared_fd); + + smbw_setenv("SMBW_HANDLE", s); + + return; + + failed: + perror("Failed to setup shared variable area "); + exit(1); +} + +static int locked; + +/***************************************************** +lock the shared variable area +*******************************************************/ +static void lockit(void) +{ + if (shared_fd == 0) { + char *p = getenv("SMBW_HANDLE"); + if (!p) { + DEBUG(0,("ERROR: can't get smbw shared handle\n")); + exit(1); + } + shared_fd = atoi(p); + } + if (locked==0 && + fcntl_lock(shared_fd,SMB_F_SETLKW,0,1,F_WRLCK)==False) { + DEBUG(0,("ERROR: can't get smbw shared lock (%s)\n", strerror(errno))); + exit(1); + } + locked++; +} + +/***************************************************** +unlock the shared variable area +*******************************************************/ +static void unlockit(void) +{ + locked--; + if (locked == 0) { + fcntl_lock(shared_fd,SMB_F_SETLK,0,1,F_UNLCK); + } +} + + +/***************************************************** +get a variable from the shared area +*******************************************************/ +char *smbw_getshared(const char *name) +{ + int i; + struct stat st; + char *var; + + lockit(); + + /* maybe the area has changed */ + if (fstat(shared_fd, &st)) goto failed; + + if (st.st_size != shared_size) { + var = (char *)Realloc(variables, st.st_size); + if (!var) goto failed; + else variables = var; + shared_size = st.st_size; + lseek(shared_fd, 0, SEEK_SET); + if (read(shared_fd, variables, shared_size) != shared_size) { + goto failed; + } + } + + unlockit(); + + i=0; + while (i < shared_size) { + char *n, *v; + int l1, l2; + + l1 = SVAL(&variables[i], 0); + l2 = SVAL(&variables[i], 2); + + n = &variables[i+4]; + v = &variables[i+4+l1]; + i += 4+l1+l2; + + if (strcmp(name,n)) { + continue; + } + return v; + } + + return NULL; + + failed: + DEBUG(0,("smbw: shared variables corrupt (%s)\n", strerror(errno))); + exit(1); + return NULL; +} + + + +/***************************************************** +set a variable in the shared area +*******************************************************/ +void smbw_setshared(const char *name, const char *val) +{ + int l1, l2; + char *var; + + /* we don't allow variable overwrite */ + if (smbw_getshared(name)) return; + + lockit(); + + l1 = strlen(name)+1; + l2 = strlen(val)+1; + + var = (char *)Realloc(variables, shared_size + l1+l2+4); + + if (!var) { + DEBUG(0,("out of memory in smbw_setshared\n")); + exit(1); + } + + variables = var; + + SSVAL(&variables[shared_size], 0, l1); + SSVAL(&variables[shared_size], 2, l2); + + pstrcpy(&variables[shared_size] + 4, name); + pstrcpy(&variables[shared_size] + 4 + l1, val); + + shared_size += l1+l2+4; + + lseek(shared_fd, 0, SEEK_SET); + if (write(shared_fd, variables, shared_size) != shared_size) { + DEBUG(0,("smbw_setshared failed (%s)\n", strerror(errno))); + exit(1); + } + + unlockit(); +} + + +/***************************************************************** +set an env variable - some systems don't have this +*****************************************************************/ +int smbw_setenv(const char *name, const char *value) +{ + pstring s; + char *p; + int ret = -1; + + slprintf(s,sizeof(s)-1,"%s=%s", name, value); + + p = strdup(s); + + if (p) ret = putenv(p); + + return ret; +} + +/***************************************************************** +return true if the passed fd is the SMBW_HANDLE +*****************************************************************/ +int smbw_shared_fd(int fd) +{ + return (shared_fd && shared_fd == fd); +} |