/*
* This function returns an NSPR PRFileDesc * which the caller can read to
* obtain the prestine value of the shared library, before any OS related
* changes to it (usually address fixups).
*
* If prelink is installed, this
* file descriptor is a pipe connecting the output of
* /usr/sbin/prelink -u -o - {Library}
* and *pid returns the process id of the prelink child.
*
* If prelink is not installed, it returns a normal readonly handle to the
* library itself and *pid is set to '0'.
*/
PRFileDesc *
bl_OpenUnPrelink(const char *shName, int *pid)
{
char *command= strdup(FREEBL_PRELINK_COMMAND);
char *argString = NULL;
char **argv = NULL;
char *shNameArg = NULL;
char *cp;
pid_t child;
int argc = 0, argNext = 0;
struct stat statBuf;
int pipefd[2] = {-1,-1};
int ret;
*pid = 0;
/* make sure the prelink command exists first. If not, fall back to
* just reading the file */
for (cp = command; *cp ; cp++) {
if (*cp == ' ') {
*cp++ = 0;
argString = cp;
break;
}
}
memset (&statBuf, 0, sizeof(statBuf));
/* stat the file, follow the link */
ret = stat(command, &statBuf);
if (ret < 0) {
free(command);
return PR_Open(shName, PR_RDONLY, 0);
}
/* file exits, make sure it's an executable */
if (!S_ISREG(statBuf.st_mode) ||
((statBuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)) {
free(command);
return PR_Open(shName, PR_RDONLY, 0);
}
/* OK, the prelink command exists and looks correct, use it */
/* build the arglist while we can still malloc */
/* count the args if any */
if (argString && *argString) {
/* argString may have leading spaces, strip them off*/
for (cp = argString; *cp && *cp == ' '; cp++);
argString = cp;
if (*cp) {
/* there is at least one arg.. */
argc = 1;
}
/* count the rest: Note there is no provision for escaped
* spaces here */
for (cp = argString; *cp ; cp++) {
if (*cp == ' ') {
while (*cp && *cp == ' ') cp++;
if (*cp) argc++;
}
}
}
/* add the additional args: argv[0] (command), shName, NULL*/
argc += 3;
argv = PORT_NewArray(char *, argc);
if (argv == NULL) {
goto loser;
}
/* fill in the arglist */
argv[argNext++] = command;
if (argString && *argString) {
argv[argNext++] = argString;
for (cp = argString; *cp; cp++) {
if (*cp == ' ') {
*cp++ = 0;
while (*cp && *cp == ' ') cp++;
if (*cp) argv[argNext++] = cp;
}
}
}
/* exec doesn't advertise taking const char **argv, do the paranoid
* copy */
shNameArg = strdup(shName);
if (shNameArg == NULL) {
goto loser;
}
argv[argNext++] = shNameArg;
argv[argNext++] = 0;
ret = pipe(pipefd);
if (ret < 0) {
goto loser;
}
/* use vfork() so we don't trigger the pthread_at_fork() handlers */
child = vfork();
if (child < 0) goto loser;
if (child == 0) {
/* set up the file descriptors */
/* if we need to support BSD, this will need to be an open of
* /dev/null and dup2(nullFD, 0)*/
close(0);
/* associate pipefd[1] with stdout */
if (pipefd[1] != 1) dup2(pipefd[1], 1);
close(2);
close(pipefd[0]);
/* should probably close the other file descriptors? */
execv(command, argv);
/* avoid at_exit() handlers */
_exit(1); /* shouldn't reach here except on an error */
}
close(pipefd[1]);
pipefd[1] = -1;
/* this is safe because either vfork() as full fork() semantics, and thus
* already has it's own address space, or because vfork() has paused
* the parent util the exec or exit */
free(command);
free(shNameArg);
PORT_Free(argv);
*pid = child;
return PR_ImportPipe(pipefd[0]);
loser:
if (pipefd[0] != -1) {
close(pipefd[0]);
}
if (pipefd[1] != -1) {
close(pipefd[1]);
}
free(command);
free(shNameArg);
PORT_Free(argv);
return NULL;
}
PR_IMPLEMENT(PRFileDesc *) PR_GetInheritedFD(
const char *name)
{
PRFileDesc *fd;
const char *envVar;
const char *ptr;
int len = strlen(name);
PROsfd osfd;
int nColons;
PRIntn fileType;
envVar = PR_GetEnv("NSPR_INHERIT_FDS");
if (NULL == envVar || '\0' == envVar[0]) {
PR_SetError(PR_UNKNOWN_ERROR, 0);
return NULL;
}
ptr = envVar;
while (1) {
if ((ptr[len] == ':') && (strncmp(ptr, name, len) == 0)) {
ptr += len + 1;
PR_sscanf(ptr, "%d:0x%" PR_SCNxOSFD, &fileType, &osfd);
switch ((PRDescType)fileType) {
case PR_DESC_FILE:
fd = PR_ImportFile(osfd);
break;
case PR_DESC_PIPE:
fd = PR_ImportPipe(osfd);
break;
case PR_DESC_SOCKET_TCP:
fd = PR_ImportTCPSocket(osfd);
break;
case PR_DESC_SOCKET_UDP:
fd = PR_ImportUDPSocket(osfd);
break;
default:
PR_ASSERT(0);
PR_SetError(PR_UNKNOWN_ERROR, 0);
fd = NULL;
break;
}
if (fd) {
/*
* An inherited FD is inheritable by default.
* The child process needs to call PR_SetFDInheritable
* to make it non-inheritable if so desired.
*/
fd->secret->inheritable = _PR_TRI_TRUE;
}
return fd;
}
/* Skip three colons */
nColons = 0;
while (*ptr) {
if (*ptr == ':') {
if (++nColons == 3) {
break;
}
}
ptr++;
}
if (*ptr == '\0') {
PR_SetError(PR_UNKNOWN_ERROR, 0);
return NULL;
}
ptr++;
}
}
