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mirror of https://github.com/Unidata/netcdf-c.git synced 2024-12-21 08:39:46 +08:00
netcdf-c/libdispatch/drc.c
Dennis Heimbigner 78f259ab48 Provide Documentation for the .rc File Mechanism and API
re: Issue https://github.com/Unidata/netcdf-c/issues/2952

The documentation -- such as it is -- is lost inside
docs/auth.md. So, create docs/quickstart_env.md to describe how
.rc file mechanism is used, and include the netcdf-c API.  Also
add list of environment variables used by the netcdf-c library.
2024-07-30 13:51:32 -06:00

753 lines
19 KiB
C

/*
Copyright (c) 1998-2018 University Corporation for Atmospheric Research/Unidata
See COPYRIGHT for license information.
*/
#include "config.h"
#include <stddef.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDARG_H
#include <stdarg.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "netcdf.h"
#include "ncbytes.h"
#include "ncuri.h"
#include "ncrc.h"
#include "nclog.h"
#include "ncauth.h"
#include "ncpathmgr.h"
#include "nc4internal.h"
#include "ncs3sdk.h"
#include "ncdispatch.h"
#undef NOREAD
#undef DRCDEBUG
#undef LEXDEBUG
#undef PARSEDEBUG
#define RTAG ']'
#define LTAG '['
#undef MEMCHECK
#define MEMCHECK(x) if((x)==NULL) {goto nomem;} else {}
/* Forward */
static int NC_rcload(void);
static char* rcreadline(char** nextlinep);
static void rctrim(char* text);
static void rcorder(NClist* rc);
static int rccompile(const char* path);
static int rcequal(NCRCentry* e1, NCRCentry* e2);
static int rclocatepos(const char* key, const char* hostport, const char* urlpath);
static struct NCRCentry* rclocate(const char* key, const char* hostport, const char* urlpath);
static int rcsearch(const char* prefix, const char* rcname, char** pathp);
static void rcfreeentries(NClist* rc);
static void rcfreeentry(NCRCentry* t);
#ifdef DRCDEBUG
static void storedump(char* msg, NClist* entrys);
#endif
/* Define default rc files and aliases, also defines load order*/
static const char* rcfilenames[] = {".ncrc", ".daprc", ".dodsrc", NULL};
static int NCRCinitialized = 0;
/**************************************************/
/* User API */
/**
The most common case is to get the most general value for a key,
where most general means that the urlpath and hostport are null
So this function returns the value associated with the key
where the .rc entry has the simple form "key=value".
If that entry is not found, then return NULL.
@param key table entry key field
@param table entry key field
@return value matching the key -- caller frees
@return NULL if no entry of the form key=value exists
*/
char*
nc_rc_get(const char* key)
{
NCglobalstate* ncg = NULL;
char* value = NULL;
if(!NC_initialized) nc_initialize();
ncg = NC_getglobalstate();
assert(ncg != NULL && ncg->rcinfo != NULL && ncg->rcinfo->entries != NULL);
if(ncg->rcinfo->ignore) goto done;
value = NC_rclookup(key,NULL,NULL);
done:
value = nulldup(value);
return value;
}
/**
Set simple key=value in .rc table.
Will overwrite any existing value.
@param key
@param value
@return NC_NOERR if success
@return NC_EINVAL if fail
*/
int
nc_rc_set(const char* key, const char* value)
{
int stat = NC_NOERR;
NCglobalstate* ncg = NULL;
if(!NC_initialized) nc_initialize();
ncg = NC_getglobalstate();
assert(ncg != NULL && ncg->rcinfo != NULL && ncg->rcinfo->entries != NULL);
if(ncg->rcinfo->ignore) goto done;;
stat = NC_rcfile_insert(key,NULL,NULL,value);
done:
return stat;
}
/**************************************************/
/* External Entry Points */
/*
Initialize defaults and load:
* .ncrc
* .dodsrc
* ${HOME}/.aws/config
* ${HOME}/.aws/credentials
For debugging support, it is possible
to change where the code looks for the .aws directory.
This is set by the environment variable NC_TEST_AWS_DIR.
*/
void
ncrc_initialize(void)
{
int stat = NC_NOERR;
NCglobalstate* ncg = NULL;
if(NCRCinitialized) return;
NCRCinitialized = 1; /* prevent recursion */
ncg = NC_getglobalstate();
#ifndef NOREAD
/* Load entrys */
if((stat = NC_rcload())) {
nclog(NCLOGWARN,".rc loading failed");
}
/* Load .aws/config &/ credentials */
if((stat = NC_aws_load_credentials(ncg))) {
nclog(NCLOGWARN,"AWS config file not loaded");
}
#endif
}
static void
ncrc_setrchome(void)
{
const char* tmp = NULL;
NCglobalstate* ncg = NC_getglobalstate();
assert(ncg && ncg->home);
if(ncg->rcinfo->rchome) return;
tmp = getenv(NCRCENVHOME);
if(tmp == NULL || strlen(tmp) == 0)
tmp = ncg->home;
ncg->rcinfo->rchome = strdup(tmp);
#ifdef DRCDEBUG
fprintf(stderr,"ncrc_setrchome: %s\n",ncg->rcinfo->rchome);
#endif
}
void
NC_rcclear(NCRCinfo* info)
{
if(info == NULL) return;
nullfree(info->rcfile);
nullfree(info->rchome);
rcfreeentries(info->entries);
NC_s3freeprofilelist(info->s3profiles);
}
static void
rcfreeentry(NCRCentry* t)
{
nullfree(t->host);
nullfree(t->urlpath);
nullfree(t->key);
nullfree(t->value);
free(t);
}
static void
rcfreeentries(NClist* rc)
{
size_t i;
for(i=0;i<nclistlength(rc);i++) {
NCRCentry* t = (NCRCentry*)nclistget(rc,i);
rcfreeentry(t);
}
nclistfree(rc);
}
/* locate, read and compile the rc files, if any */
static int
NC_rcload(void)
{
size_t i;
int ret = NC_NOERR;
char* path = NULL;
NCglobalstate* globalstate = NULL;
NClist* rcfileorder = nclistnew();
if(!NCRCinitialized) ncrc_initialize();
globalstate = NC_getglobalstate();
if(globalstate->rcinfo->ignore) {
nclog(NCLOGNOTE,".rc file loading suppressed");
goto done;
}
if(globalstate->rcinfo->loaded) goto done;
/* locate the configuration files in order of use:
1. Specified by NCRCENV_RC environment variable.
2. If NCRCENV_RC is not set then merge the set of rc files in this order:
1. $HOME/.ncrc
2. $HOME/.dodsrc
3. $CWD/.ncrc
4. $CWD/.dodsrc
Entries in later files override any of the earlier files
*/
if(globalstate->rcinfo->rcfile != NULL) { /* always use this */
nclistpush(rcfileorder,strdup(globalstate->rcinfo->rcfile));
} else {
const char** rcname;
const char* dirnames[3];
const char** dir;
/* Make sure rcinfo.rchome is defined */
ncrc_setrchome();
dirnames[0] = globalstate->rcinfo->rchome;
dirnames[1] = globalstate->cwd;
dirnames[2] = NULL;
for(dir=dirnames;*dir;dir++) {
for(rcname=rcfilenames;*rcname;rcname++) {
ret = rcsearch(*dir,*rcname,&path);
if(ret == NC_NOERR && path != NULL)
nclistpush(rcfileorder,path);
path = NULL;
}
}
}
for(i=0;i<nclistlength(rcfileorder);i++) {
path = (char*)nclistget(rcfileorder,i);
if((ret=rccompile(path))) {
nclog(NCLOGWARN, "Error parsing %s\n",path);
ret = NC_NOERR; /* ignore it */
goto done;
}
}
done:
globalstate->rcinfo->loaded = 1; /* even if not exists */
nclistfreeall(rcfileorder);
return (ret);
}
/**
* Locate a entry by property key.
* If duplicate keys, first takes precedence.
* @param key to lookup
* @param hostport to use for lookup
* @param urlpath to use for lookup
* @return the value of the key or NULL if not found.
*/
char*
NC_rclookup(const char* key, const char* hostport, const char* urlpath)
{
struct NCRCentry* entry = NULL;
if(!NCRCinitialized) ncrc_initialize();
entry = rclocate(key,hostport,urlpath);
return (entry == NULL ? NULL : entry->value);
}
/**
* Locate a entry by property key and uri.
* If duplicate keys, first takes precedence.
*/
char*
NC_rclookupx(NCURI* uri, const char* key)
{
char* hostport = NULL;
char* result = NULL;
hostport = NC_combinehostport(uri);
result = NC_rclookup(key,hostport,uri->path);
nullfree(hostport);
return result;
}
#if 0
/*!
Set the absolute path to use for the rc file.
WARNING: this MUST be called before any other
call in order for this to take effect.
\param[in] rcfile The path to use. If NULL then do not use any rcfile.
\retval OC_NOERR if the request succeeded.
\retval OC_ERCFILE if the file failed to load
*/
int
NC_set_rcfile(const char* rcfile)
{
int stat = NC_NOERR;
FILE* f = NULL;
NCglobalstate* globalstate = NC_getglobalstate();
if(rcfile != NULL && strlen(rcfile) == 0)
rcfile = NULL;
f = NCfopen(rcfile,"r");
if(f == NULL) {
stat = NC_ERCFILE;
goto done;
}
fclose(f);
nullfree(globalstate->rcinfo->rcfile);
globalstate->rcinfo->rcfile = strdup(rcfile);
/* Clear globalstate->rcinfo */
NC_rcclear(&globalstate->rcinfo);
/* (re) load the rcfile and esp the entriestore*/
stat = NC_rcload();
done:
return stat;
}
#endif
/**************************************************/
/* RC processing functions */
static char*
rcreadline(char** nextlinep)
{
char* line;
char* p;
line = (p = *nextlinep);
if(*p == '\0') return NULL; /*signal done*/
for(;*p;p++) {
if(*p == '\r' && p[1] == '\n') *p = '\0';
else if(*p == '\n') break;
}
*p++ = '\0'; /* null terminate line; overwrite newline */
*nextlinep = p;
return line;
}
/* Trim TRIMCHARS from both ends of text; */
static void
rctrim(char* text)
{
char* p;
char* q;
size_t len = 0;
if(text == NULL || *text == '\0') return;
len = strlen(text);
/* elide upto first non-trimchar */
for(q=text,p=text;*p;p++) {
if(*p != ' ' && *p != '\t' && *p != '\r') {*q++ = *p;}
}
len = strlen(p);
/* locate last non-trimchar */
if(len > 0) {
for(size_t i = len; i-->0;) {
p = &text[i];
if(*p != ' ' && *p != '\t' && *p != '\r') {break;}
*p = '\0'; /* elide trailing trimchars */
}
}
}
/* Order the entries: those with urls must be first,
but otherwise relative order does not matter.
*/
static void
rcorder(NClist* rc)
{
size_t i;
size_t len = nclistlength(rc);
NClist* tmprc = NULL;
if(rc == NULL || len == 0) return;
tmprc = nclistnew();
/* Two passes: 1) pull entries with host */
for(i=0;i<len;i++) {
NCRCentry* ti = nclistget(rc,i);
if(ti->host == NULL) continue;
nclistpush(tmprc,ti);
}
/* pass 2 pull entries without host*/
for(i=0;i<len;i++) {
NCRCentry* ti = nclistget(rc,i);
if(ti->host != NULL) continue;
nclistpush(tmprc,ti);
}
/* Move tmp to rc */
nclistsetlength(rc,0);
for(i=0;i<len;i++) {
NCRCentry* ti = nclistget(tmprc,i);
nclistpush(rc,ti);
}
#ifdef DRCDEBUG
storedump("reorder:",rc);
#endif
nclistfree(tmprc);
}
/* Merge a entry store from a file*/
static int
rccompile(const char* filepath)
{
int ret = NC_NOERR;
NClist* rc = NULL;
char* contents = NULL;
NCbytes* tmp = ncbytesnew();
NCURI* uri = NULL;
char* nextline = NULL;
NCglobalstate* globalstate = NC_getglobalstate();
NCS3INFO s3;
memset(&s3,0,sizeof(s3));
if((ret=NC_readfile(filepath,tmp))) {
nclog(NCLOGWARN, "Could not open configuration file: %s",filepath);
goto done;
}
contents = ncbytesextract(tmp);
if(contents == NULL) contents = strdup("");
/* Either reuse or create new */
rc = globalstate->rcinfo->entries;
if(rc == NULL) {
rc = nclistnew();
globalstate->rcinfo->entries = rc;
}
nextline = contents;
for(;;) {
char* line;
char* key = NULL;
char* value = NULL;
char* host = NULL;
char* urlpath = NULL;
size_t llen;
NCRCentry* entry;
line = rcreadline(&nextline);
if(line == NULL) break; /* done */
rctrim(line); /* trim leading and trailing blanks */
if(line[0] == '#') continue; /* comment */
if((llen=strlen(line)) == 0) continue; /* empty line */
if(line[0] == LTAG) {
char* url = ++line;
char* rtag = strchr(line,RTAG);
if(rtag == NULL) {
nclog(NCLOGERR, "Malformed [url] in %s entry: %s",filepath,line);
continue;
}
line = rtag + 1;
*rtag = '\0';
/* compile the url and pull out the host, port, and path */
if(uri) ncurifree(uri);
if(ncuriparse(url,&uri)) {
nclog(NCLOGERR, "Malformed [url] in %s entry: %s",filepath,line);
continue;
}
if(NC_iss3(uri,NULL)) {
NCURI* newuri = NULL;
/* Rebuild the url to S3 "path" format */
NC_s3clear(&s3);
if((ret = NC_s3urlrebuild(uri,&s3,&newuri))) goto done;
ncurifree(uri);
uri = newuri;
newuri = NULL;
}
/* Get the host+port */
ncbytesclear(tmp);
ncbytescat(tmp,uri->host);
if(uri->port != NULL) {
ncbytesappend(tmp,':');
ncbytescat(tmp,uri->port);
}
ncbytesnull(tmp);
host = ncbytesextract(tmp);
if(strlen(host)==0) /* nullify host */
{free(host); host = NULL;}
/* Get the url path part */
urlpath = uri->path;
if(urlpath && strlen(urlpath)==0) urlpath = NULL; /* nullify */
}
/* split off key and value */
key=line;
value = strchr(line, '=');
if(value == NULL)
value = line + strlen(line);
else {
*value = '\0';
value++;
}
/* See if key already exists */
entry = rclocate(key,host,urlpath);
if(entry == NULL) {
entry = (NCRCentry*)calloc(1,sizeof(NCRCentry));
if(entry == NULL) {ret = NC_ENOMEM; goto done;}
nclistpush(rc,entry);
entry->host = host; host = NULL;
entry->urlpath = nulldup(urlpath);
entry->key = nulldup(key);
rctrim(entry->host);
rctrim(entry->urlpath);
rctrim(entry->key);
}
nullfree(entry->value);
entry->value = nulldup(value);
rctrim(entry->value);
#ifdef DRCDEBUG
fprintf(stderr,"rc: host=%s urlpath=%s key=%s value=%s\n",
(entry->host != NULL ? entry->host : "<null>"),
(entry->urlpath != NULL ? entry->urlpath : "<null>"),
entry->key,entry->value);
#endif
entry = NULL;
}
#ifdef DRCDEBUG
fprintf(stderr,"reorder.path=%s\n",filepath);
#endif
rcorder(rc);
done:
NC_s3clear(&s3);
if(contents) free(contents);
ncurifree(uri);
ncbytesfree(tmp);
return (ret);
}
/**
Encapsulate equality comparison: return 1|0
*/
static int
rcequal(NCRCentry* e1, NCRCentry* e2)
{
int nulltest;
if(e1->key == NULL || e2->key == NULL) return 0;
if(strcmp(e1->key,e2->key) != 0) return 0;
/* test hostport; take NULL into account*/
nulltest = 0;
if(e1->host == NULL) nulltest |= 1;
if(e2->host == NULL) nulltest |= 2;
/* Use host to decide if entry applies */
switch (nulltest) {
case 0: if(strcmp(e1->host,e2->host) != 0) {return 0;} break;
case 1: break; /* .rc->host == NULL && candidate->host != NULL */
case 2: return 0; /* .rc->host != NULL && candidate->host == NULL */
case 3: break; /* .rc->host == NULL && candidate->host == NULL */
default: return 0;
}
/* test urlpath take NULL into account*/
nulltest = 0;
if(e1->urlpath == NULL) nulltest |= 1;
if(e2->urlpath == NULL) nulltest |= 2;
switch (nulltest) {
case 0: if(strcmp(e1->urlpath,e2->urlpath) != 0) {return 0;} break;
case 1: break; /* .rc->urlpath == NULL && candidate->urlpath != NULL */
case 2: return 0; /* .rc->urlpath != NULL && candidate->urlpath == NULL */
case 3: break; /* .rc->urlpath == NULL && candidate->urlpath == NULL */
default: return 0;
}
return 1;
}
/**
* (Internal) Locate a entry by property key and host+port (may be null) and urlpath (may be null)
* If duplicate keys, first takes precedence.
*/
static int
rclocatepos(const char* key, const char* hostport, const char* urlpath)
{
size_t i;
NCglobalstate* globalstate = NC_getglobalstate();
struct NCRCinfo* info = globalstate->rcinfo;
NCRCentry* entry = NULL;
NCRCentry candidate;
NClist* rc = info->entries;
if(info->ignore) return -1;
candidate.key = (char*)key;
candidate.value = (char*)NULL;
candidate.host = (char*)hostport;
candidate.urlpath = (char*)urlpath;
for(i=0;i<nclistlength(rc);i++) {
entry = (NCRCentry*)nclistget(rc,i);
if(rcequal(entry,&candidate)) return (int)i;
}
return -1;
}
/**
* (Internal) Locate a entry by property key and host+port (may be null or "").
* If duplicate keys, first takes precedence.
*/
static struct NCRCentry*
rclocate(const char* key, const char* hostport, const char* urlpath)
{
int pos;
NCglobalstate* globalstate = NC_getglobalstate();
struct NCRCinfo* info = globalstate->rcinfo;
if(globalstate->rcinfo->ignore) return NULL;
if(key == NULL || info == NULL) return NULL;
pos = rclocatepos(key,hostport,urlpath);
if(pos < 0) return NULL;
return NC_rcfile_ith(info,(size_t)pos);
}
/**
* Locate rc file by searching in directory prefix.
*/
static
int
rcsearch(const char* prefix, const char* rcname, char** pathp)
{
char* path = NULL;
FILE* f = NULL;
size_t plen = (prefix?strlen(prefix):0);
size_t rclen = strlen(rcname);
int ret = NC_NOERR;
size_t pathlen = plen+rclen+1+1; /*+1 for '/' +1 for nul */
path = (char*)malloc(pathlen); /* +1 for nul*/
if(path == NULL) {ret = NC_ENOMEM; goto done;}
snprintf(path, pathlen, "%s/%s", prefix, rcname);
/* see if file is readable */
f = NCfopen(path,"r");
if(f != NULL)
nclog(NCLOGNOTE, "Found rc file=%s",path);
done:
if(f == NULL || ret != NC_NOERR) {
nullfree(path);
path = NULL;
}
if(f != NULL)
fclose(f);
if(pathp != NULL)
*pathp = path;
else {
nullfree(path);
path = NULL;
}
errno = 0; /* silently ignore errors */
return (ret);
}
int
NC_rcfile_insert(const char* key, const char* hostport, const char* urlpath, const char* value)
{
int ret = NC_NOERR;
/* See if this key already defined */
struct NCRCentry* entry = NULL;
NCglobalstate* globalstate = NULL;
NClist* rc = NULL;
if(!NCRCinitialized) ncrc_initialize();
if(key == NULL || value == NULL)
{ret = NC_EINVAL; goto done;}
globalstate = NC_getglobalstate();
rc = globalstate->rcinfo->entries;
if(rc == NULL) {
rc = nclistnew();
globalstate->rcinfo->entries = rc;
if(rc == NULL) {ret = NC_ENOMEM; goto done;}
}
entry = rclocate(key,hostport,urlpath);
if(entry == NULL) {
entry = (NCRCentry*)calloc(1,sizeof(NCRCentry));
if(entry == NULL) {ret = NC_ENOMEM; goto done;}
entry->key = strdup(key);
entry->value = NULL;
rctrim(entry->key);
entry->host = nulldup(hostport);
rctrim(entry->host);
entry->urlpath = nulldup(urlpath);
rctrim(entry->urlpath);
nclistpush(rc,entry);
}
if(entry->value != NULL) free(entry->value);
entry->value = strdup(value);
rctrim(entry->value);
#ifdef DRCDEBUG
storedump("NC_rcfile_insert",rc);
#endif
done:
return ret;
}
/* Obtain the count of number of entries */
size_t
NC_rcfile_length(NCRCinfo* info)
{
return nclistlength(info->entries);
}
/* Obtain the ith entry; return NULL if out of range */
NCRCentry*
NC_rcfile_ith(NCRCinfo* info, size_t i)
{
if(i >= nclistlength(info->entries))
return NULL;
return (NCRCentry*)nclistget(info->entries,i);
}
#ifdef DRCDEBUG
static void
storedump(char* msg, NClist* entries)
{
int i;
if(msg != NULL) fprintf(stderr,"%s\n",msg);
if(entries == NULL || nclistlength(entries)==0) {
fprintf(stderr,"<EMPTY>\n");
return;
}
for(i=0;i<nclistlength(entries);i++) {
NCRCentry* t = (NCRCentry*)nclistget(entries,i);
fprintf(stderr,"\t%s\t%s\t%s\n",
((t->host == NULL || strlen(t->host)==0)?"--":t->host),t->key,t->value);
}
fflush(stderr);
}
#endif