cdrom.image/updates/checkbootloader.py

#!/usr/bin/python
#
# Check to see whether it looks like GRUB or LILO is the boot loader
# being used on the system.
#
# Jeremy Katz <katzj@redhat.com>
# Peter Jones <pjones@redhat.com>
#
# Copyright 2001,2005 Red Hat, Inc.
#
# This software may be freely redistributed under the terms of the GNU
# library public license.
#
# You should have received a copy of the GNU Library Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

import os
import string

grubConfigFile = "/boot/grub/grub.conf"
liloConfigFile = "/etc/lilo.conf"
yabootConfigFile = "/etc/yaboot.conf"
siloConfigFile = "/etc/silo.conf"


# XXX: this is cut and pasted directly from booty/bootloaderInfo.py
# should eventually just go from there
def getDiskPart(dev):
    """Return (disk, partition number) tuple for dev"""
    cut = len(dev)
    if (dev[:3] == "rd/" or dev[:4] == "ida/" or
        dev[:6] == "cciss/"):
        if dev[-2] == 'p':
            cut = -1
        elif dev[-3] == 'p':
            cut = -2
    else:
        if dev[-2] in string.digits:
            cut = -2
        elif dev[-1] in string.digits:
            cut = -1

    name = dev[:cut]
    
    # hack off the trailing 'p' from /dev/cciss/*, for example
    if name[-1] == 'p':
        for letter in name:
            if letter not in string.letters and letter != "/":
                name = name[:-1]
                break

    if cut < 0:
        partNum = int(dev[cut:]) - 1
    else:
        partNum = None

    return (name, partNum)


def getRaidDisks(raidDevice, raidLevel=None, stripPart=1):
    rc = []
    if raidLevel is not None:
        try:
            raidLevel = "raid%d" % (int(raidLevel),)
        except ValueError:
            pass

    try:
        f = open("/proc/mdstat", "r")
        lines = f.readlines()
        f.close()
    except:
        return rc
    
    for line in lines:
        fields = string.split(line, ' ')
        if fields[0] == raidDevice:
            if raidLevel is not None and fields[3] != raidLevel:
                continue
            for field in fields[4:]:
                if string.find(field, "[") == -1:
                    continue
                dev = string.split(field, '[')[0]
                if len(dev) == 0:
                    continue
                if stripPart:
                    disk = getDiskPart(dev)[0]
                    rc.append(disk)
                else:
                    rc.append(dev)

    return rc
            

def getBootBlock(bootDev, instRoot, seekBlocks=0):
    """Get the boot block from bootDev.  Return a 512 byte string."""
    block = " " * 512
    if bootDev is None:
        return block

    # get the devices in the raid device
    if bootDev[5:7] == "md":
        bootDevs = getRaidDisks(bootDev[5:])
        bootDevs.sort()
    else:
        bootDevs = [ bootDev[5:] ]

    # FIXME: this is kind of a hack
    # look at all of the devs in the raid device until we can read the
    # boot block for one of them.  should do this better at some point
    # by looking at all of the drives properly
    for dev in bootDevs:
        try:
            fd = os.open("%s/dev/%s" % (instRoot, dev), os.O_RDONLY)
            if seekBlocks > 0:
                os.lseek(fd, seekBlocks * 512, 0)
            block = os.read(fd, 512)
            os.close(fd)
            return block
        except:
            pass
    return block

# takes a line like #boot=/dev/hda and returns /dev/hda
# also handles cases like quoted versions and other nonsense
def getBootDevString(line):
    dev = string.split(line, '=')[1]
    dev = string.strip(dev)
    dev = string.replace(dev, '"', '')
    dev = string.replace(dev, "'", "")
    return dev

def getBootloaderTypeAndBoot(instRoot = "/"):
    haveGrubConf = 1
    haveLiloConf = 1
    haveYabootConf = 1
    haveSiloConf = 1
    
    bootDev = None
    
    # make sure they have the config file, otherwise we definitely can't
    # use that bootloader
    if not os.access(instRoot + grubConfigFile, os.R_OK):
        haveGrubConf = 0
    if not os.access(instRoot + liloConfigFile, os.R_OK):
        haveLiloConf = 0
    if not os.access(instRoot + yabootConfigFile, os.R_OK):
        haveYabootConf = 0
    if not os.access(instRoot + siloConfigFile, os.R_OK):
        haveSiloConf = 0

    if haveGrubConf:
        bootDev = None
        for (fn, stanza) in [ ("/etc/sysconfig/grub", "boot="),
                              (grubConfigFile, "#boot=") ]:
            try:
                f = open(instRoot + fn, "r")
            except:
                continue
        
            # the following bits of code are straight from checkbootloader.py
            lines = f.readlines()
            f.close()
            for line in lines:
                if line.startswith(stanza):
                    bootDev = getBootDevString(line)
                    break
            if bootDev is not None:
                break

        if bootDev is not None:
            block = getBootBlock(bootDev, instRoot)
            # XXX I don't like this, but it's what the maintainer suggested :(
            if string.find(block, "GRUB") >= 0:
                return ("GRUB", bootDev)

    if haveLiloConf:
        f = open(instRoot + liloConfigFile, "r")
        lines = f.readlines()
        for line in lines:
            if line[0:5] == "boot=":
                bootDev = getBootDevString(line)                
                break

        block = getBootBlock(bootDev, instRoot)
        # this at least is well-defined
        if block[6:10] == "LILO":
            return ("LILO", bootDev)

    if haveYabootConf:
        f = open(instRoot + yabootConfigFile, "r")
        lines = f.readlines()
        for line in lines:
            if line[0:5] == "boot=":
                bootDev = getBootDevString(line)                

        if bootDev:
                return ("YABOOT", bootDev)

    if haveSiloConf:
        bootDev = None
        # We've never done the /etc/sysconfig/silo thing, but maybe 
        # we should start...
        for (fn, stanza) in [ ("/etc/sysconfig/silo", "boot="),
                              (grubConfigFile, "#boot=") ]:
            try:
                f = open(instRoot + fn, "r")
            except:
                continue

            lines = f.readlines()
            f.close()
            for line in lines:
                if line.startswith(stanza):
                    bootDev = getBootDevString(line)
                    break
            if bootDev is not None:
                break

        if bootDev is not None:
            # XXX SILO sucks just like grub.
            if getDiskPart(bootDev)[1] != 3:
                block = getBootBlock(bootDev, instRoot, 1)
                if block[24:28] == "SILO":
                    return ("SILO", bootDev)

    return (None, None)

def whichBootLoader(instRoot = "/"):        
    ret = getBootloaderTypeAndBoot(instRoot)
    if not ret:
        return None
    else:
        return ret[0]

if __name__ == "__main__":
    bootloader = whichBootLoader()
    if bootloader:
        print "Found %s." % (bootloader)
    else:
        print "Unable to determine boot loader."
1	#!/usr/bin/python
2	#
3	# Check to see whether it looks like GRUB or LILO is the boot loader
4	# being used on the system.
5	#
6	# Jeremy Katz <katzj@redhat.com>
7	# Peter Jones <pjones@redhat.com>
8	#
9	# Copyright 2001,2005 Red Hat, Inc.
10	#
11	# This software may be freely redistributed under the terms of the GNU
12	# library public license.
13	#
14	# You should have received a copy of the GNU Library Public License
15	# along with this program; if not, write to the Free Software
16	# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17
18	import os
19	import string
20
21	grubConfigFile = "/boot/grub/grub.conf"
22	liloConfigFile = "/etc/lilo.conf"
23	yabootConfigFile = "/etc/yaboot.conf"
24	siloConfigFile = "/etc/silo.conf"
25
26
27	# XXX: this is cut and pasted directly from booty/bootloaderInfo.py
28	# should eventually just go from there
29	def getDiskPart(dev):
30	"""Return (disk, partition number) tuple for dev"""
31	cut = len(dev)
32	if (dev[:3] == "rd/" or dev[:4] == "ida/" or
33	dev[:6] == "cciss/"):
34	if dev[-2] == 'p':
35	cut = -1
36	elif dev[-3] == 'p':
37	cut = -2
38	else:
39	if dev[-2] in string.digits:
40	cut = -2
41	elif dev[-1] in string.digits:
42	cut = -1
43
44	name = dev[:cut]
45
46	# hack off the trailing 'p' from /dev/cciss/*, for example
47	if name[-1] == 'p':
48	for letter in name:
49	if letter not in string.letters and letter != "/":
50	name = name[:-1]
51	break
52
53	if cut < 0:
54	partNum = int(dev[cut:]) - 1
55	else:
56	partNum = None
57
58	return (name, partNum)
59
60
61	def getRaidDisks(raidDevice, raidLevel=None, stripPart=1):
62	rc = []
63	if raidLevel is not None:
64	try:
65	raidLevel = "raid%d" % (int(raidLevel),)
66	except ValueError:
67	pass
68
69	try:
70	f = open("/proc/mdstat", "r")
71	lines = f.readlines()
72	f.close()
73	except:
74	return rc
75
76	for line in lines:
77	fields = string.split(line, ' ')
78	if fields[0] == raidDevice:
79	if raidLevel is not None and fields[3] != raidLevel:
80	continue
81	for field in fields[4:]:
82	if string.find(field, "[") == -1:
83	continue
84	dev = string.split(field, '[')[0]
85	if len(dev) == 0:
86	continue
87	if stripPart:
88	disk = getDiskPart(dev)[0]
89	rc.append(disk)
90	else:
91	rc.append(dev)
92
93	return rc
94
95
96	def getBootBlock(bootDev, instRoot, seekBlocks=0):
97	"""Get the boot block from bootDev. Return a 512 byte string."""
98	block = " " * 512
99	if bootDev is None:
100	return block
101
102	# get the devices in the raid device
103	if bootDev[5:7] == "md":
104	bootDevs = getRaidDisks(bootDev[5:])
105	bootDevs.sort()
106	else:
107	bootDevs = [ bootDev[5:] ]
108
109	# FIXME: this is kind of a hack
110	# look at all of the devs in the raid device until we can read the
111	# boot block for one of them. should do this better at some point
112	# by looking at all of the drives properly
113	for dev in bootDevs:
114	try:
115	fd = os.open("%s/dev/%s" % (instRoot, dev), os.O_RDONLY)
116	if seekBlocks > 0:
117	os.lseek(fd, seekBlocks * 512, 0)
118	block = os.read(fd, 512)
119	os.close(fd)
120	return block
121	except:
122	pass
123	return block
124
125	# takes a line like #boot=/dev/hda and returns /dev/hda
126	# also handles cases like quoted versions and other nonsense
127	def getBootDevString(line):
128	dev = string.split(line, '=')[1]
129	dev = string.strip(dev)
130	dev = string.replace(dev, '"', '')
131	dev = string.replace(dev, "'", "")
132	return dev
133
134	def getBootloaderTypeAndBoot(instRoot = "/"):
135	haveGrubConf = 1
136	haveLiloConf = 1
137	haveYabootConf = 1
138	haveSiloConf = 1
139
140	bootDev = None
141
142	# make sure they have the config file, otherwise we definitely can't
143	# use that bootloader
144	if not os.access(instRoot + grubConfigFile, os.R_OK):
145	haveGrubConf = 0
146	if not os.access(instRoot + liloConfigFile, os.R_OK):
147	haveLiloConf = 0
148	if not os.access(instRoot + yabootConfigFile, os.R_OK):
149	haveYabootConf = 0
150	if not os.access(instRoot + siloConfigFile, os.R_OK):
151	haveSiloConf = 0
152
153	if haveGrubConf:
154	bootDev = None
155	for (fn, stanza) in [ ("/etc/sysconfig/grub", "boot="),
156	(grubConfigFile, "#boot=") ]:
157	try:
158	f = open(instRoot + fn, "r")
159	except:
160	continue
161
162	# the following bits of code are straight from checkbootloader.py
163	lines = f.readlines()
164	f.close()
165	for line in lines:
166	if line.startswith(stanza):
167	bootDev = getBootDevString(line)
168	break
169	if bootDev is not None:
170	break
171
172	if bootDev is not None:
173	block = getBootBlock(bootDev, instRoot)
174	# XXX I don't like this, but it's what the maintainer suggested :(
175	if string.find(block, "GRUB") >= 0:
176	return ("GRUB", bootDev)
177
178	if haveLiloConf:
179	f = open(instRoot + liloConfigFile, "r")
180	lines = f.readlines()
181	for line in lines:
182	if line[0:5] == "boot=":
183	bootDev = getBootDevString(line)
184	break
185
186	block = getBootBlock(bootDev, instRoot)
187	# this at least is well-defined
188	if block[6:10] == "LILO":
189	return ("LILO", bootDev)
190
191	if haveYabootConf:
192	f = open(instRoot + yabootConfigFile, "r")
193	lines = f.readlines()
194	for line in lines:
195	if line[0:5] == "boot=":
196	bootDev = getBootDevString(line)
197
198	if bootDev:
199	return ("YABOOT", bootDev)
200
201	if haveSiloConf:
202	bootDev = None
203	# We've never done the /etc/sysconfig/silo thing, but maybe
204	# we should start...
205	for (fn, stanza) in [ ("/etc/sysconfig/silo", "boot="),
206	(grubConfigFile, "#boot=") ]:
207	try:
208	f = open(instRoot + fn, "r")
209	except:
210	continue
211
212	lines = f.readlines()
213	f.close()
214	for line in lines:
215	if line.startswith(stanza):
216	bootDev = getBootDevString(line)
217	break
218	if bootDev is not None:
219	break
220
221	if bootDev is not None:
222	# XXX SILO sucks just like grub.
223	if getDiskPart(bootDev)[1] != 3:
224	block = getBootBlock(bootDev, instRoot, 1)
225	if block[24:28] == "SILO":
226	return ("SILO", bootDev)
227
228	return (None, None)
229
230	def whichBootLoader(instRoot = "/"):
231	ret = getBootloaderTypeAndBoot(instRoot)
232	if not ret:
233	return None
234	else:
235	return ret[0]
236
237	if __name__ == "__main__":
238	bootloader = whichBootLoader()
239	if bootloader:
240	print "Found %s." % (bootloader)
241	else:
242	print "Unable to determine boot loader."