diff options
| -rw-r--r-- | udev/lib/libudev-monitor.c | 42 | ||||
| -rw-r--r-- | udev/lib/libudev-private.h | 2 | ||||
| -rw-r--r-- | udev/lib/libudev-util.c | 72 |
3 files changed, 36 insertions, 80 deletions
diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c index 570fcafbb4..a0f93546f7 100644 --- a/udev/lib/libudev-monitor.c +++ b/udev/lib/libudev-monitor.c @@ -56,8 +56,9 @@ struct udev_monitor_netlink_header { unsigned short properties_off; unsigned short properties_len; /* - * crc32 of some common device properties to filter with socket filters in the client - * used in the kernel from socket filter rules; needs to be stored in network order + * hashes of some common device propertie strings to filter with socket filters in + * the client used in the kernel from socket filter rules; needs to be stored in + * network order */ unsigned int filter_subsystem; }; @@ -247,11 +248,11 @@ static int filter_apply(struct udev_monitor *udev_monitor) /* add all subsystem match values */ udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) { const char *subsys = udev_list_entry_get_name(list_entry); - unsigned int crc; + unsigned int hash; - crc = util_crc32((unsigned char *)subsys, strlen(subsys)); + hash = util_string_hash32(subsys); /* jump if value does not match */ - bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, crc, 0, 1); + bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1); /* matched, pass packet */ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff); @@ -414,8 +415,9 @@ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monito struct cmsghdr *cmsg; struct sockaddr_nl snl; struct ucred *cred; - char buf[4096]; - size_t bufpos; + char buf[8192]; + ssize_t buflen; + ssize_t bufpos; struct udev_monitor_netlink_header *nlh; int devpath_set = 0; int subsystem_set = 0; @@ -440,12 +442,18 @@ retry: smsg.msg_namelen = sizeof(snl); } - if (recvmsg(udev_monitor->sock, &smsg, 0) < 0) { + buflen = recvmsg(udev_monitor->sock, &smsg, 0); + if (buflen < 0) { if (errno != EINTR) info(udev_monitor->udev, "unable to receive message\n"); return NULL; } + if (buflen < 32 || (size_t)buflen >= sizeof(buf)) { + info(udev_monitor->udev, "invalid message length\n"); + return NULL; + } + if (udev_monitor->snl.nl_family != 0) { if (snl.nl_groups == 0) { info(udev_monitor->udev, "unicast netlink message ignored\n"); @@ -469,18 +477,20 @@ retry: return NULL; } - nlh = (struct udev_monitor_netlink_header *) buf; - if (nlh->magic == ntohl(UDEV_MONITOR_MAGIC)) { - /* udev message with version magic */ + if (strncmp(buf, "udev-", 5) == 0) { + /* udev message needs proper version magic */ + nlh = (struct udev_monitor_netlink_header *) buf; + if (nlh->magic != htonl(UDEV_MONITOR_MAGIC)) + return NULL; if (nlh->properties_off < sizeof(struct udev_monitor_netlink_header)) return NULL; - if (nlh->properties_off+32U > sizeof(buf)) + if (nlh->properties_off+32U > buflen) return NULL; bufpos = nlh->properties_off; } else { /* kernel message with header */ bufpos = strlen(buf) + 1; - if (bufpos < sizeof("a@/d") || bufpos >= sizeof(buf)) { + if ((size_t)bufpos < sizeof("a@/d") || bufpos >= buflen) { info(udev_monitor->udev, "invalid message length\n"); return NULL; } @@ -497,7 +507,7 @@ retry: return NULL; } - while (bufpos < sizeof(buf)) { + while (bufpos < buflen) { char *key; size_t keylen; @@ -629,7 +639,6 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi smsg.msg_namelen = udev_monitor->addrlen; } else if (udev_monitor->snl.nl_family != 0) { const char *val; - size_t vlen; struct udev_monitor_netlink_header nlh; @@ -638,8 +647,7 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi util_strlcpy(nlh.version, "udev-" VERSION, sizeof(nlh.version)); nlh.magic = htonl(UDEV_MONITOR_MAGIC); val = udev_device_get_subsystem(udev_device); - vlen = strlen(val); - nlh.filter_subsystem = htonl(util_crc32((unsigned char *)val, vlen)); + nlh.filter_subsystem = htonl(util_string_hash32(val)); iov[0].iov_base = &nlh; iov[0].iov_len = sizeof(struct udev_monitor_netlink_header); diff --git a/udev/lib/libudev-private.h b/udev/lib/libudev-private.h index 178004c485..0756efea81 100644 --- a/udev/lib/libudev-private.h +++ b/udev/lib/libudev-private.h @@ -173,5 +173,5 @@ extern int udev_util_replace_whitespace(const char *str, char *to, size_t len); extern int udev_util_replace_chars(char *str, const char *white); extern int udev_util_encode_string(const char *str, char *str_enc, size_t len); extern void util_set_fd_cloexec(int fd); -extern unsigned int util_crc32(const unsigned char *buf, size_t len); +extern unsigned int util_string_hash32(const char *str); #endif diff --git a/udev/lib/libudev-util.c b/udev/lib/libudev-util.c index 018e2cdb08..2b8cda59f6 100644 --- a/udev/lib/libudev-util.c +++ b/udev/lib/libudev-util.c @@ -462,67 +462,15 @@ void util_set_fd_cloexec(int fd) fcntl(fd, F_SETFD, flags); } -unsigned int util_crc32(const unsigned char *buf, size_t len) +unsigned int util_string_hash32(const char *str) { - unsigned int crc; - const unsigned char *end; - static const unsigned int crc32_table[256] = { - 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, - 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, - 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, - 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, - 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, - 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, - 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, - 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, - 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, - 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, - 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, - 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, - 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, - 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, - 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, - 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, - 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, - 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, - 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, - 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, - 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, - 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, - 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, - 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, - 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, - 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, - 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, - 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, - 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, - 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, - 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, - 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, - 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, - 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, - 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, - 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, - 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, - 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, - 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, - 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, - 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, - 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, - 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, - 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, - 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, - 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, - 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, - 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, - 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, - 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, - 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, - 0x2d02ef8d - }; - - crc = 0xffffffff; - for (end = buf + len; buf < end; ++buf) - crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); - return ~crc; + unsigned int hash = 0; + + while (str[0] != '\0') { + hash += str[0] << 4; + hash += str[0] >> 4; + hash *= 11; + str++; + } + return hash; } |