cups/scheduler/util.c

449 lines
8.6 KiB
C

/*
* Mini-daemon utility functions for CUPS.
*
* Copyright 2007-2014 by Apple Inc.
* Copyright 1997-2005 by Easy Software Products.
*
* Licensed under Apache License v2.0. See the file "LICENSE" for more information.
*/
/*
* Include necessary headers...
*/
#include "util.h"
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef __APPLE__
# include <libgen.h>
extern char **environ;
#endif /* __APPLE__ */
/*
* 'cupsdCompareNames()' - Compare two names.
*
* This function basically does a _cups_strcasecmp() of the two strings,
* but is also aware of numbers so that "a2" < "a100".
*/
int /* O - Result of comparison */
cupsdCompareNames(const char *s, /* I - First string */
const char *t) /* I - Second string */
{
int diff, /* Difference between digits */
digits; /* Number of digits */
/*
* Loop through both names, returning only when a difference is
* seen. Also, compare whole numbers rather than just characters, too!
*/
while (*s && *t)
{
if (isdigit(*s & 255) && isdigit(*t & 255))
{
/*
* Got a number; start by skipping leading 0's...
*/
while (*s == '0')
s ++;
while (*t == '0')
t ++;
/*
* Skip equal digits...
*/
while (isdigit(*s & 255) && *s == *t)
{
s ++;
t ++;
}
/*
* Bounce out if *s and *t aren't both digits...
*/
if (isdigit(*s & 255) && !isdigit(*t & 255))
return (1);
else if (!isdigit(*s & 255) && isdigit(*t & 255))
return (-1);
else if (!isdigit(*s & 255) || !isdigit(*t & 255))
continue;
if (*s < *t)
diff = -1;
else
diff = 1;
/*
* Figure out how many more digits there are...
*/
digits = 0;
s ++;
t ++;
while (isdigit(*s & 255))
{
digits ++;
s ++;
}
while (isdigit(*t & 255))
{
digits --;
t ++;
}
/*
* Return if the number or value of the digits is different...
*/
if (digits < 0)
return (-1);
else if (digits > 0)
return (1);
else if (diff)
return (diff);
}
else if (tolower(*s) < tolower(*t))
return (-1);
else if (tolower(*s) > tolower(*t))
return (1);
else
{
s ++;
t ++;
}
}
/*
* Return the results of the final comparison...
*/
if (*s)
return (1);
else if (*t)
return (-1);
else
return (0);
}
/*
* 'cupsdCreateStringsArray()' - Create a CUPS array of strings.
*/
cups_array_t * /* O - CUPS array */
cupsdCreateStringsArray(const char *s) /* I - Comma-delimited strings */
{
if (!s || !*s)
return (NULL);
else
return (_cupsArrayNewStrings(s, ','));
}
/*
* 'cupsdExec()' - Run a program with the correct environment.
*
* On macOS, we need to update the CFProcessPath environment variable that
* is passed in the environment so the child can access its bundled resources.
*/
int /* O - exec() status */
cupsdExec(const char *command, /* I - Full path to program */
char **argv) /* I - Command-line arguments */
{
#ifdef __APPLE__
int i, j; /* Looping vars */
char *envp[500], /* Array of environment variables */
cfprocesspath[1024], /* CFProcessPath environment variable */
linkpath[1024]; /* Link path for symlinks... */
int linkbytes; /* Bytes for link path */
/*
* Some macOS programs are bundled and need the CFProcessPath environment
* variable defined. If the command is a symlink, resolve the link and point
* to the resolved location, otherwise, use the command path itself.
*/
if ((linkbytes = readlink(command, linkpath, sizeof(linkpath) - 1)) > 0)
{
/*
* Yes, this is a symlink to the actual program, nul-terminate and
* use it...
*/
linkpath[linkbytes] = '\0';
if (linkpath[0] == '/')
snprintf(cfprocesspath, sizeof(cfprocesspath), "CFProcessPath=%s",
linkpath);
else
snprintf(cfprocesspath, sizeof(cfprocesspath), "CFProcessPath=%s/%s",
dirname((char *)command), linkpath);
}
else
snprintf(cfprocesspath, sizeof(cfprocesspath), "CFProcessPath=%s", command);
envp[0] = cfprocesspath;
/*
* Copy the rest of the environment except for any CFProcessPath that may
* already be there...
*/
for (i = 1, j = 0;
environ[j] && i < (int)(sizeof(envp) / sizeof(envp[0]) - 1);
j ++)
if (strncmp(environ[j], "CFProcessPath=", 14))
envp[i ++] = environ[j];
envp[i] = NULL;
/*
* Use execve() to run the program...
*/
return (execve(command, argv, envp));
#else
/*
* On other operating systems, just call execv() to use the same environment
* variables as the parent...
*/
return (execv(command, argv));
#endif /* __APPLE__ */
}
/*
* 'cupsdPipeCommand()' - Read output from a command.
*/
cups_file_t * /* O - CUPS file or NULL on error */
cupsdPipeCommand(int *pid, /* O - Process ID or 0 on error */
const char *command, /* I - Command to run */
char **argv, /* I - Arguments to pass to command */
uid_t user) /* I - User to run as or 0 for current */
{
int fd, /* Temporary file descriptor */
fds[2]; /* Pipe file descriptors */
/*
* First create the pipe...
*/
if (pipe(fds))
{
*pid = 0;
return (NULL);
}
/*
* Set the "close on exec" flag on each end of the pipe...
*/
if (fcntl(fds[0], F_SETFD, fcntl(fds[0], F_GETFD) | FD_CLOEXEC))
{
close(fds[0]);
close(fds[1]);
*pid = 0;
return (NULL);
}
if (fcntl(fds[1], F_SETFD, fcntl(fds[1], F_GETFD) | FD_CLOEXEC))
{
close(fds[0]);
close(fds[1]);
*pid = 0;
return (NULL);
}
/*
* Then run the command...
*/
if ((*pid = fork()) < 0)
{
/*
* Unable to fork!
*/
*pid = 0;
close(fds[0]);
close(fds[1]);
return (NULL);
}
else if (!*pid)
{
/*
* Child comes here...
*/
if (!getuid() && user)
setuid(user); /* Run as restricted user */
if ((fd = open("/dev/null", O_RDONLY)) > 0)
{
dup2(fd, 0); /* </dev/null */
close(fd);
}
dup2(fds[1], 1); /* >pipe */
close(fds[1]);
cupsdExec(command, argv);
exit(errno);
}
/*
* Parent comes here, open the input side of the pipe...
*/
close(fds[1]);
return (cupsFileOpenFd(fds[0], "r"));
}
/*
* 'cupsdSendIPPGroup()' - Send a group tag.
*/
void
cupsdSendIPPGroup(ipp_tag_t group_tag) /* I - Group tag */
{
/*
* Send IPP group tag (1 byte)...
*/
putchar(group_tag);
}
/*
* 'cupsdSendIPPHeader()' - Send the IPP response header.
*/
void
cupsdSendIPPHeader(
ipp_status_t status_code, /* I - Status code */
int request_id) /* I - Request ID */
{
/*
* Send IPP/1.1 response header: version number (2 bytes), status code
* (2 bytes), and request ID (4 bytes)...
*
* TODO: Add version number (IPP/2.x and IPP/1.0) support.
*/
putchar(1);
putchar(1);
putchar(status_code >> 8);
putchar(status_code);
putchar(request_id >> 24);
putchar(request_id >> 16);
putchar(request_id >> 8);
putchar(request_id);
}
/*
* 'cupsdSendIPPInteger()' - Send an integer attribute.
*/
void
cupsdSendIPPInteger(
ipp_tag_t value_tag, /* I - Value tag */
const char *name, /* I - Attribute name */
int value) /* I - Attribute value */
{
size_t len; /* Length of attribute name */
/*
* Send IPP integer value: value tag (1 byte), name length (2 bytes),
* name string (without nul), value length (2 bytes), and value (4 bytes)...
*/
putchar(value_tag);
len = strlen(name);
putchar((int)(len >> 8));
putchar((int)len);
fputs(name, stdout);
putchar(0);
putchar(4);
putchar(value >> 24);
putchar(value >> 16);
putchar(value >> 8);
putchar(value);
}
/*
* 'cupsdSendIPPString()' - Send a string attribute.
*/
void
cupsdSendIPPString(
ipp_tag_t value_tag, /* I - Value tag */
const char *name, /* I - Attribute name */
const char *value) /* I - Attribute value */
{
size_t len; /* Length of attribute name */
/*
* Send IPP string value: value tag (1 byte), name length (2 bytes),
* name string (without nul), value length (2 bytes), and value string
* (without nul)...
*/
putchar(value_tag);
len = strlen(name);
putchar((int)(len >> 8));
putchar((int)len);
fputs(name, stdout);
len = strlen(value);
putchar((int)(len >> 8));
putchar((int)len);
fputs(value, stdout);
}
/*
* 'cupsdSendIPPTrailer()' - Send the end-of-message tag.
*/
void
cupsdSendIPPTrailer(void)
{
putchar(IPP_TAG_END);
fflush(stdout);
}