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      1 /*
      2 **
      3 ** Copyright 2007-2014, The Android Open Source Project
      4 **
      5 ** This file is dual licensed.  It may be redistributed and/or modified
      6 ** under the terms of the Apache 2.0 License OR version 2 of the GNU
      7 ** General Public License.
      8 */
      9 
     10 #ifndef _LIBS_LOG_LOGGER_H
     11 #define _LIBS_LOG_LOGGER_H
     12 
     13 #include <stdint.h>
     14 #ifdef __linux__
     15 #include <time.h> /* clockid_t definition */
     16 #endif
     17 
     18 #include <log/log.h>
     19 #include <log/log_read.h>
     20 
     21 #ifdef __cplusplus
     22 extern "C" {
     23 #endif
     24 
     25 /*
     26  * The userspace structure for version 1 of the logger_entry ABI.
     27  * This structure is returned to userspace by the kernel logger
     28  * driver unless an upgrade to a newer ABI version is requested.
     29  */
     30 struct logger_entry {
     31     uint16_t    len;    /* length of the payload */
     32     uint16_t    __pad;  /* no matter what, we get 2 bytes of padding */
     33     int32_t     pid;    /* generating process's pid */
     34     int32_t     tid;    /* generating process's tid */
     35     int32_t     sec;    /* seconds since Epoch */
     36     int32_t     nsec;   /* nanoseconds */
     37     char        msg[0]; /* the entry's payload */
     38 } __attribute__((__packed__));
     39 
     40 /*
     41  * The userspace structure for version 2 of the logger_entry ABI.
     42  * This structure is returned to userspace if ioctl(LOGGER_SET_VERSION)
     43  * is called with version==2; or used with the user space log daemon.
     44  */
     45 struct logger_entry_v2 {
     46     uint16_t    len;       /* length of the payload */
     47     uint16_t    hdr_size;  /* sizeof(struct logger_entry_v2) */
     48     int32_t     pid;       /* generating process's pid */
     49     int32_t     tid;       /* generating process's tid */
     50     int32_t     sec;       /* seconds since Epoch */
     51     int32_t     nsec;      /* nanoseconds */
     52     uint32_t    euid;      /* effective UID of logger */
     53     char        msg[0];    /* the entry's payload */
     54 } __attribute__((__packed__));
     55 
     56 struct logger_entry_v3 {
     57     uint16_t    len;       /* length of the payload */
     58     uint16_t    hdr_size;  /* sizeof(struct logger_entry_v3) */
     59     int32_t     pid;       /* generating process's pid */
     60     int32_t     tid;       /* generating process's tid */
     61     int32_t     sec;       /* seconds since Epoch */
     62     int32_t     nsec;      /* nanoseconds */
     63     uint32_t    lid;       /* log id of the payload */
     64     char        msg[0];    /* the entry's payload */
     65 } __attribute__((__packed__));
     66 
     67 struct logger_entry_v4 {
     68     uint16_t    len;       /* length of the payload */
     69     uint16_t    hdr_size;  /* sizeof(struct logger_entry_v4) */
     70     int32_t     pid;       /* generating process's pid */
     71     uint32_t    tid;       /* generating process's tid */
     72     uint32_t    sec;       /* seconds since Epoch */
     73     uint32_t    nsec;      /* nanoseconds */
     74     uint32_t    lid;       /* log id of the payload, bottom 4 bits currently */
     75     uint32_t    uid;       /* generating process's uid */
     76     char        msg[0];    /* the entry's payload */
     77 } __attribute__((__packed__));
     78 
     79 /*
     80  * The maximum size of the log entry payload that can be
     81  * written to the logger. An attempt to write more than
     82  * this amount will result in a truncated log entry.
     83  */
     84 #define LOGGER_ENTRY_MAX_PAYLOAD	4068
     85 
     86 /*
     87  * The maximum size of a log entry which can be read from the
     88  * kernel logger driver. An attempt to read less than this amount
     89  * may result in read() returning EINVAL.
     90  */
     91 #define LOGGER_ENTRY_MAX_LEN		(5*1024)
     92 
     93 #define NS_PER_SEC 1000000000ULL
     94 
     95 struct log_msg {
     96     union {
     97         unsigned char buf[LOGGER_ENTRY_MAX_LEN + 1];
     98         struct logger_entry_v4 entry;
     99         struct logger_entry_v4 entry_v4;
    100         struct logger_entry_v3 entry_v3;
    101         struct logger_entry_v2 entry_v2;
    102         struct logger_entry    entry_v1;
    103     } __attribute__((aligned(4)));
    104 #ifdef __cplusplus
    105     /* Matching log_time operators */
    106     bool operator== (const log_msg &T) const
    107     {
    108         return (entry.sec == T.entry.sec) && (entry.nsec == T.entry.nsec);
    109     }
    110     bool operator!= (const log_msg &T) const
    111     {
    112         return !(*this == T);
    113     }
    114     bool operator< (const log_msg &T) const
    115     {
    116         return (entry.sec < T.entry.sec)
    117             || ((entry.sec == T.entry.sec)
    118              && (entry.nsec < T.entry.nsec));
    119     }
    120     bool operator>= (const log_msg &T) const
    121     {
    122         return !(*this < T);
    123     }
    124     bool operator> (const log_msg &T) const
    125     {
    126         return (entry.sec > T.entry.sec)
    127             || ((entry.sec == T.entry.sec)
    128              && (entry.nsec > T.entry.nsec));
    129     }
    130     bool operator<= (const log_msg &T) const
    131     {
    132         return !(*this > T);
    133     }
    134     uint64_t nsec() const
    135     {
    136         return static_cast<uint64_t>(entry.sec) * NS_PER_SEC + entry.nsec;
    137     }
    138 
    139     /* packet methods */
    140     log_id_t id()
    141     {
    142         return (log_id_t) entry.lid;
    143     }
    144     char *msg()
    145     {
    146         return entry.hdr_size ? (char *) buf + entry.hdr_size : entry_v1.msg;
    147     }
    148     unsigned int len()
    149     {
    150         return (entry.hdr_size ? entry.hdr_size : sizeof(entry_v1)) + entry.len;
    151     }
    152 #endif
    153 };
    154 
    155 struct logger;
    156 
    157 log_id_t android_logger_get_id(struct logger *logger);
    158 
    159 int android_logger_clear(struct logger *logger);
    160 long android_logger_get_log_size(struct logger *logger);
    161 int android_logger_set_log_size(struct logger *logger, unsigned long size);
    162 long android_logger_get_log_readable_size(struct logger *logger);
    163 int android_logger_get_log_version(struct logger *logger);
    164 
    165 struct logger_list;
    166 
    167 ssize_t android_logger_get_statistics(struct logger_list *logger_list,
    168                                       char *buf, size_t len);
    169 ssize_t android_logger_get_prune_list(struct logger_list *logger_list,
    170                                       char *buf, size_t len);
    171 int android_logger_set_prune_list(struct logger_list *logger_list,
    172                                   char *buf, size_t len);
    173 
    174 #define ANDROID_LOG_RDONLY   O_RDONLY
    175 #define ANDROID_LOG_WRONLY   O_WRONLY
    176 #define ANDROID_LOG_RDWR     O_RDWR
    177 #define ANDROID_LOG_ACCMODE  O_ACCMODE
    178 #define ANDROID_LOG_NONBLOCK O_NONBLOCK
    179 #define ANDROID_LOG_WRAP     0x40000000 /* Block until buffer about to wrap */
    180 #define ANDROID_LOG_WRAP_DEFAULT_TIMEOUT 7200 /* 2 hour default */
    181 #define ANDROID_LOG_PSTORE   0x80000000
    182 
    183 struct logger_list *android_logger_list_alloc(int mode,
    184                                               unsigned int tail,
    185                                               pid_t pid);
    186 struct logger_list *android_logger_list_alloc_time(int mode,
    187                                                    log_time start,
    188                                                    pid_t pid);
    189 void android_logger_list_free(struct logger_list *logger_list);
    190 /* In the purest sense, the following two are orthogonal interfaces */
    191 int android_logger_list_read(struct logger_list *logger_list,
    192                              struct log_msg *log_msg);
    193 
    194 /* Multiple log_id_t opens */
    195 struct logger *android_logger_open(struct logger_list *logger_list,
    196                                    log_id_t id);
    197 #define android_logger_close android_logger_free
    198 /* Single log_id_t open */
    199 struct logger_list *android_logger_list_open(log_id_t id,
    200                                              int mode,
    201                                              unsigned int tail,
    202                                              pid_t pid);
    203 #define android_logger_list_close android_logger_list_free
    204 
    205 #ifdef __linux__
    206 clockid_t android_log_clockid();
    207 #endif
    208 
    209 /*
    210  * log_id_t helpers
    211  */
    212 log_id_t android_name_to_log_id(const char *logName);
    213 const char *android_log_id_to_name(log_id_t log_id);
    214 
    215 #ifdef __cplusplus
    216 }
    217 #endif
    218 
    219 #endif /* _LIBS_LOG_LOGGER_H */
    220